diff --git a/blocks/classes/output/block_contents.php b/blocks/classes/output/block_contents.php
index aeb12971102..6d8f7850e4c 100644
--- a/blocks/classes/output/block_contents.php
+++ b/blocks/classes/output/block_contents.php
@@ -30,7 +30,7 @@ namespace core_block\output;
  * @copyright 2009 Tim Hunt
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since Moodle 2.0
- * @package core
+ * @package core_block
  * @category output
  */
 class block_contents {
@@ -51,7 +51,7 @@ class block_contents {
     /**
      * @var int All the blocks (or things that look like blocks) printed on
      * a page are given a unique number that can be used to construct id="" attributes.
-     * This is set automatically be the {@link prepare()} method.
+     * This is set automatically be the {@see prepare()} method.
      * Do not try to set it manually.
      */
     public $skipid;
@@ -71,7 +71,7 @@ class block_contents {
 
     /**
      * @var array An array of attribute => value pairs that are put on the outer div of this
-     * block. {@link $id} and {@link $classes} attributes should be set separately.
+     * block. {@see $id} and {@see $classes} attributes should be set separately.
      */
     public $attributes;
 
@@ -122,23 +122,24 @@ class block_contents {
      * this array should be an array('url' => $url, 'icon' => $icon, 'caption' => $caption).
      * $icon is the icon name. Fed to $OUTPUT->image_url.
      */
-    public $controls = array();
+    public $controls = [];
 
 
     /**
-     * Create new instance of block content
-     * @param array $attributes
+     * Create new instance of block content.
+     *
+     * @param null|array $attributes
      */
-    public function __construct(array $attributes = null) {
+    public function __construct(?array $attributes = null) {
         $this->skipid = self::$idcounter;
         self::$idcounter += 1;
 
         if ($attributes) {
-            // standard block
+            // Standard block.
             $this->attributes = $attributes;
         } else {
-            // simple "fake" blocks used in some modules and "Add new block" block
-            $this->attributes = array('class'=>'block');
+            // Simple "fake" blocks used in some modules and "Add new block" block.
+            $this->attributes = ['class' => 'block'];
         }
     }
 
@@ -148,7 +149,7 @@ class block_contents {
      * @param string $class
      */
     public function add_class($class) {
-        $this->attributes['class'] .= ' '.$class;
+        $this->attributes['class'] .= ' ' . $class;
     }
 
     /**
diff --git a/blocks/classes/output/block_move_target.php b/blocks/classes/output/block_move_target.php
index d698ac21c7d..d305a901daa 100644
--- a/blocks/classes/output/block_move_target.php
+++ b/blocks/classes/output/block_move_target.php
@@ -28,7 +28,7 @@ use moodle_url;
  * @copyright 2009 Tim Hunt
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since Moodle 2.0
- * @package core
+ * @package core_block
  * @category output
  */
 class block_move_target {
diff --git a/lib/classes/output/action_link.php b/lib/classes/output/action_link.php
index bb094108d05..c34d69ef17a 100644
--- a/lib/classes/output/action_link.php
+++ b/lib/classes/output/action_link.php
@@ -59,15 +59,17 @@ class action_link implements renderable {
      * Constructor
      * @param moodle_url $url
      * @param string $text HTML fragment
-     * @param component_action $action
-     * @param array $attributes associative array of html link attributes + disabled
-     * @param pix_icon $icon optional pix_icon to render with the link text
+     * @param null|component_action $action
+     * @param null|array $attributes associative array of html link attributes + disabled
+     * @param null|pix_icon $icon optional pix_icon to render with the link text
      */
-    public function __construct(moodle_url $url,
+    public function __construct(
+        moodle_url $url,
         $text,
-        component_action $action=null,
-        array $attributes=null,
-        pix_icon $icon=null) {
+        ?component_action $action = null,
+        ?array $attributes = null,
+        ?pix_icon $icon = null
+    ) {
         $this->url = clone($url);
         $this->text = $text;
         if (empty($attributes['id'])) {
@@ -144,14 +146,14 @@ class action_link implements renderable {
         $data->classes = isset($attributes['class']) ? $attributes['class'] : '';
         unset($attributes['class']);
 
-        $data->attributes = array_map(function($key, $value) {
+        $data->attributes = array_map(function ($key, $value) {
             return [
                 'name' => $key,
-                'value' => $value
+                'value' => $value,
             ];
         }, array_keys($attributes), $attributes);
 
-        $data->actions = array_map(function($action) use ($output) {
+        $data->actions = array_map(function ($action) use ($output) {
             return $action->export_for_template($output);
         }, !empty($this->actions) ? $this->actions : []);
         $data->hasactions = !empty($this->actions);
diff --git a/lib/classes/output/action_menu.php b/lib/classes/output/action_menu.php
index 1bbdeb22cc2..588753e652e 100644
--- a/lib/classes/output/action_menu.php
+++ b/lib/classes/output/action_menu.php
@@ -64,35 +64,35 @@ class action_menu implements renderable, templatable {
     protected $instance = 0;
 
     /**
-     * An array of primary actions. Please use {@link action_menu::add_primary_action()} to add actions.
+     * An array of primary actions. Please use {@see action_menu::add_primary_action()} to add actions.
      * @var array
      */
-    protected $primaryactions = array();
+    protected $primaryactions = [];
 
     /**
-     * An array of secondary actions. Please use {@link action_menu::add_secondary_action()} to add actions.
+     * An array of secondary actions. Please use {@see action_menu::add_secondary_action()} to add actions.
      * @var array
      */
-    protected $secondaryactions = array();
+    protected $secondaryactions = [];
 
     /**
      * An array of attributes added to the container of the action menu.
      * Initialised with defaults during construction.
      * @var array
      */
-    public $attributes = array();
+    public $attributes = [];
     /**
      * An array of attributes added to the container of the primary actions.
      * Initialised with defaults during construction.
      * @var array
      */
-    public $attributesprimary = array();
+    public $attributesprimary = [];
     /**
      * An array of attributes added to the container of the secondary actions.
      * Initialised with defaults during construction.
      * @var array
      */
-    public $attributessecondary = array();
+    public $attributessecondary = [];
 
     /**
      * The string to use next to the icon for the action icon relating to the secondary (dropdown) menu.
@@ -147,27 +147,27 @@ class action_menu implements renderable, templatable {
      *
      * @param array $actions An array of actions (action_menu_link|pix_icon|string).
      */
-    public function __construct(array $actions = array()) {
+    public function __construct(array $actions = []) {
         static $initialised = 0;
         $this->instance = $initialised;
         $initialised++;
 
-        $this->attributes = array(
-            'id' => 'action-menu-'.$this->instance,
+        $this->attributes = [
+            'id' => 'action-menu-' . $this->instance,
             'class' => 'moodle-actionmenu',
-            'data-enhance' => 'moodle-core-actionmenu'
-        );
-        $this->attributesprimary = array(
-            'id' => 'action-menu-'.$this->instance.'-menubar',
+            'data-enhance' => 'moodle-core-actionmenu',
+        ];
+        $this->attributesprimary = [
+            'id' => 'action-menu-' . $this->instance . '-menubar',
             'class' => 'menubar',
-        );
-        $this->attributessecondary = array(
-            'id' => 'action-menu-'.$this->instance.'-menu',
+        ];
+        $this->attributessecondary = [
+            'id' => 'action-menu-' . $this->instance . '-menu',
             'class' => 'menu',
             'data-rel' => 'menu-content',
-            'aria-labelledby' => 'action-menu-toggle-'.$this->instance,
-            'role' => 'menu'
-        );
+            'aria-labelledby' => 'action-menu-toggle-' . $this->instance,
+            'role' => 'menu',
+        ];
         $this->dropdownalignment = 'dropdown-menu-right';
         foreach ($actions as $action) {
             $this->add($action);
@@ -207,8 +207,11 @@ class action_menu implements renderable, templatable {
      * @param string|null $extraclasses extra classes for the trigger {@see self::set_menu_trigger()}
      * @throws coding_exception
      */
-    public function set_kebab_trigger(?string $triggername = null, ?core_renderer $output = null,
-        ?string $extraclasses = '') {
+    public function set_kebab_trigger(
+        ?string $triggername = null,
+        ?core_renderer $output = null,
+        ?string $extraclasses = ''
+    ) {
         global $OUTPUT;
         if (empty($output)) {
             $output = $OUTPUT;
@@ -307,16 +310,16 @@ class action_menu implements renderable, templatable {
     /**
      * Returns the primary actions ready to be rendered.
      *
-     * @param core_renderer $output The renderer to use for getting icons.
+     * @param null|core_renderer $output The renderer to use for getting icons.
      * @return array
      */
-    public function get_primary_actions(core_renderer $output = null) {
+    public function get_primary_actions(?core_renderer $output = null) {
         global $OUTPUT;
         if ($output === null) {
             $output = $OUTPUT;
         }
         $pixicon = $this->actionicon;
-        $linkclasses = array('toggle-display');
+        $linkclasses = ['toggle-display'];
 
         $title = '';
         if (!empty($this->menutrigger)) {
@@ -328,7 +331,7 @@ class action_menu implements renderable, templatable {
                 't/edit_menu',
                 '',
                 'moodle',
-                array('class' => 'iconsmall actionmenu', 'title' => '')
+                ['class' => 'iconsmall actionmenu', 'title' => '']
             );
             $pixicon = $this->actionicon;
         }
@@ -349,14 +352,14 @@ class action_menu implements renderable, templatable {
             $label = $title;
         }
         $actions = $this->primaryactions;
-        $attributes = array(
+        $attributes = [
             'class' => implode(' ', $linkclasses),
             'title' => $title,
             'aria-label' => $label,
-            'id' => 'action-menu-toggle-'.$this->instance,
+            'id' => 'action-menu-toggle-' . $this->instance,
             'role' => 'menuitem',
             'tabindex' => '-1',
-        );
+        ];
         $link = html_writer::link('#', $string . $this->menutrigger . $pixicon, $attributes);
         if ($this->prioritise) {
             array_unshift($actions, $link);
@@ -395,12 +398,12 @@ class action_menu implements renderable, templatable {
         if (isset($this->attributessecondary['data-align'])) {
             // We've already got one set, lets remove the old class so as to avoid troubles.
             $class = $this->attributessecondary['class'];
-            $search = 'align-'.$this->attributessecondary['data-align'];
+            $search = 'align-' . $this->attributessecondary['data-align'];
             $this->attributessecondary['class'] = str_replace($search, '', $class);
         }
         $align = $this->get_align_string($dialogue) . '-' . $this->get_align_string($button);
         $this->attributessecondary['data-align'] = $align;
-        $this->attributessecondary['class'] .= ' align-'.$align;
+        $this->attributessecondary['class'] .= ' align-' . $align;
     }
 
     /**
@@ -411,15 +414,15 @@ class action_menu implements renderable, templatable {
      */
     protected function get_align_string($align) {
         switch ($align) {
-            case self::TL :
+            case self::TL:
                 return 'tl';
-            case self::TR :
+            case self::TR:
                 return 'tr';
-            case self::BL :
+            case self::BL:
                 return 'bl';
-            case self::BR :
+            case self::BR:
                 return 'br';
-            default :
+            default:
                 return 'tl';
         }
     }
@@ -502,7 +505,7 @@ class action_menu implements renderable, templatable {
             $pos = strpos($this->attributes['class'], $class);
             if ($value === true && $pos === false) {
                 // The value is true and the class has not been set yet. Add it.
-                $this->attributes['class'] .= ' '.$class;
+                $this->attributes['class'] .= ' ' . $class;
             } else if ($value === false && $pos !== false) {
                 // The value is false and the class has been set. Remove it.
                 $this->attributes['class'] = substr($this->attributes['class'], $pos, strlen($class));
@@ -520,7 +523,7 @@ class action_menu implements renderable, templatable {
      */
     public function set_additional_classes(string $class = '') {
         if (!empty($this->attributes['class'])) {
-            $this->attributes['class'] .= " ".$class;
+            $this->attributes['class'] .= " " . $class;
         } else {
             $this->attributes['class'] = $class;
         }
@@ -547,7 +550,7 @@ class action_menu implements renderable, templatable {
         $data->classes = isset($attributes['class']) ? $attributes['class'] : '';
         unset($attributes['class']);
 
-        $data->attributes = array_map(function($key, $value) {
+        $data->attributes = array_map(function ($key, $value) {
             return [ 'name' => $key, 'value' => $value ];
         }, array_keys($attributes), $attributes);
 
diff --git a/lib/classes/output/action_menu/link.php b/lib/classes/output/action_menu/link.php
index af440be5ec3..ea6b2da25f2 100644
--- a/lib/classes/output/action_menu/link.php
+++ b/lib/classes/output/action_menu/link.php
@@ -33,7 +33,6 @@ use stdClass;
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class link extends action_link implements renderable {
-
     /**
      * True if this is a primary action. False if not.
      * @var bool
@@ -49,8 +48,8 @@ class link extends action_link implements renderable {
     /**
      * The number of instances of this action menu link (and its subclasses).
      *
-     * @deprecated since Moodle 4.4.
      * @var int
+     * @deprecated since Moodle 4.4.
      */
     protected static $instance = 1;
 
@@ -63,7 +62,7 @@ class link extends action_link implements renderable {
      * @param bool $primary Whether this is a primary action or not.
      * @param array $attributes Any attribtues associated with the action.
      */
-    public function __construct(moodle_url $url, ?pix_icon $icon, $text, $primary = true, array $attributes = array()) {
+    public function __construct(moodle_url $url, ?pix_icon $icon, $text, $primary = true, array $attributes = []) {
         parent::__construct($url, $text, null, $attributes, $icon);
         $this->primary = (bool)$primary;
         $this->add_class('menu-action');
@@ -104,10 +103,10 @@ class link extends action_link implements renderable {
         $data->disabled = !empty($attributes['disabled']);
         unset($attributes['disabled']);
 
-        $data->attributes = array_map(function($key, $value) {
+        $data->attributes = array_map(function ($key, $value) {
             return [
                 'name' => $key,
-                'value' => $value
+                'value' => $value,
             ];
         }, array_keys($attributes), $attributes);
 
diff --git a/lib/classes/output/action_menu/link_primary.php b/lib/classes/output/action_menu/link_primary.php
index 3a251d93023..c7d314b98ce 100644
--- a/lib/classes/output/action_menu/link_primary.php
+++ b/lib/classes/output/action_menu/link_primary.php
@@ -36,7 +36,7 @@ class link_primary extends link {
      * @param string $text
      * @param array $attributes
      */
-    public function __construct(moodle_url $url, ?pix_icon $icon, $text, array $attributes = array()) {
+    public function __construct(moodle_url $url, ?pix_icon $icon, $text, array $attributes = []) {
         parent::__construct($url, $icon, $text, true, $attributes);
     }
 }
diff --git a/lib/classes/output/action_menu/link_secondary.php b/lib/classes/output/action_menu/link_secondary.php
index 5f71598ac15..dac7767f2ef 100644
--- a/lib/classes/output/action_menu/link_secondary.php
+++ b/lib/classes/output/action_menu/link_secondary.php
@@ -36,7 +36,7 @@ class link_secondary extends link {
      * @param string $text
      * @param array $attributes
      */
-    public function __construct(moodle_url $url, ?pix_icon $icon, $text, array $attributes = array()) {
+    public function __construct(moodle_url $url, ?pix_icon $icon, $text, array $attributes = []) {
         parent::__construct($url, $icon, $text, false, $attributes);
     }
 }
diff --git a/lib/classes/output/actions/component_action.php b/lib/classes/output/actions/component_action.php
index 39b73c218f6..e8af7e60dbf 100644
--- a/lib/classes/output/actions/component_action.php
+++ b/lib/classes/output/actions/component_action.php
@@ -31,7 +31,6 @@ use stdClass;
  * @category output
  */
 class component_action implements templatable {
-
     /**
      * @var string $event The DOM event that will trigger this action when caught
      */
@@ -48,7 +47,7 @@ class component_action implements templatable {
     /**
      * @var array An array of arguments to pass to the JS function
      */
-    public $jsfunctionargs = array();
+    public $jsfunctionargs = [];
 
     /**
      * Constructor
@@ -56,7 +55,7 @@ class component_action implements templatable {
      * @param string $jsfunction An optional JS function. Required if jsfunctionargs is given
      * @param array $jsfunctionargs An array of arguments to pass to the jsfunction
      */
-    public function __construct($event, $jsfunction, $jsfunctionargs=array()) {
+    public function __construct($event, $jsfunction, $jsfunctionargs = []) {
         $this->event = $event;
 
         $this->jsfunction = $jsfunction;
diff --git a/lib/classes/output/actions/confirm_action.php b/lib/classes/output/actions/confirm_action.php
index e49d80b3963..f18ce1c1fbd 100644
--- a/lib/classes/output/actions/confirm_action.php
+++ b/lib/classes/output/actions/confirm_action.php
@@ -37,14 +37,18 @@ class confirm_action extends component_action {
      */
     public function __construct($message, $callback = null, $continuelabel = null, $cancellabel = null) {
         if ($callback !== null) {
-            debugging('The callback argument to new confirm_action() has been deprecated.' .
+            debugging(
+                'The callback argument to new confirm_action() has been deprecated.' .
                     ' If you need to use a callback, please write Javascript to use moodle-core-notification-confirmation ' .
                     'and attach to the provided events.',
-                    DEBUG_DEVELOPER);
+                DEBUG_DEVELOPER,
+            );
         }
-        parent::__construct('click', 'M.util.show_confirm_dialog', array(
-                'message' => $message,
-                'continuelabel' => $continuelabel, 'cancellabel' => $cancellabel));
+        parent::__construct('click', 'M.util.show_confirm_dialog', [
+            'message' => $message,
+            'continuelabel' => $continuelabel,
+            'cancellabel' => $cancellabel,
+        ]);
     }
 }
 
diff --git a/lib/classes/output/actions/popup_action.php b/lib/classes/output/actions/popup_action.php
index bf1d20af3a6..9dcd3291f0a 100644
--- a/lib/classes/output/actions/popup_action.php
+++ b/lib/classes/output/actions/popup_action.php
@@ -37,20 +37,21 @@ class popup_action extends component_action {
     /**
      * @var array An array of parameters that will be passed to the openpopup JS function
      */
-    public $params = array(
-            'height' =>  400,
-            'width' => 500,
-            'top' => 0,
-            'left' => 0,
-            'menubar' => false,
-            'location' => false,
-            'scrollbars' => true,
-            'resizable' => true,
-            'toolbar' => true,
-            'status' => true,
-            'directories' => false,
-            'fullscreen' => false,
-            'dependent' => true);
+    public $params = [
+        'height' => 400,
+        'width' => 500,
+        'top' => 0,
+        'left' => 0,
+        'menubar' => false,
+        'location' => false,
+        'scrollbars' => true,
+        'resizable' => true,
+        'toolbar' => true,
+        'status' => true,
+        'directories' => false,
+        'fullscreen' => false,
+        'dependent' => true,
+    ];
 
     /**
      * Constructor
@@ -60,18 +61,18 @@ class popup_action extends component_action {
      * @param string $name The JS function to call for the popup (default 'popup')
      * @param array  $params An array of popup parameters
      */
-    public function __construct($event, $url, $name='popup', $params=array()) {
+    public function __construct($event, $url, $name = 'popup', $params = []) {
         global $CFG;
 
         $url = new moodle_url($url);
 
         if ($name) {
-            $_name = $name;
-            if (($_name = preg_replace("/\s/", '_', $_name)) != $name) {
+            $checkname = $name;
+            if (($checkname = preg_replace("/\s/", '_', $checkname)) != $name) {
                 throw new coding_exception(
-                    'The $name of a popup window shouldn\'t contain spaces - string modified. ' . $name . ' changed to ' . $_name,
+                    "The {$name} of a popup window shouldn't contain spaces - string modified. {$name} changed to {$checkname}",
                 );
-                $name = $_name;
+                $name = $checkname;
             }
         } else {
             $name = 'popup';
@@ -83,7 +84,7 @@ class popup_action extends component_action {
             }
         }
 
-        $attributes = array('url' => $url->out(false), 'name' => $name, 'options' => $this->get_js_options($params));
+        $attributes = ['url' => $url->out(false), 'name' => $name, 'options' => $this->get_js_options($params)];
         if (!empty($params['fullscreen'])) {
             $attributes['fullscreen'] = 1;
         }
@@ -102,7 +103,7 @@ class popup_action extends component_action {
         foreach ($this->params as $var => $val) {
             if (is_string($val) || is_int($val)) {
                 $jsoptions .= "$var=$val,";
-            } elseif (is_bool($val)) {
+            } else if (is_bool($val)) {
                 $jsoptions .= ($val) ? "$var," : "$var=0,";
             }
         }
diff --git a/lib/classes/output/activity_header.php b/lib/classes/output/activity_header.php
index 10c4b7f0c24..01bfd470931 100644
--- a/lib/classes/output/activity_header.php
+++ b/lib/classes/output/activity_header.php
@@ -64,8 +64,10 @@ class activity_header implements renderable, templatable {
                 $this->title = format_string($page->activityrecord->name);
             }
 
-            if (empty($layoutoptions['nodescription']) && !empty($page->activityrecord->intro) &&
-                    trim($page->activityrecord->intro)) {
+            if (
+                empty($layoutoptions['nodescription']) && !empty($page->activityrecord->intro) &&
+                    trim($page->activityrecord->intro)
+            ) {
                 $this->description = format_module_intro($this->page->activityname, $page->activityrecord, $page->cm->id);
             }
         }
diff --git a/lib/classes/output/choicelist.php b/lib/classes/output/choicelist.php
index 57d9bdc71ee..65a47919a54 100644
--- a/lib/classes/output/choicelist.php
+++ b/lib/classes/output/choicelist.php
@@ -97,13 +97,13 @@ class choicelist implements named_templatable, renderable {
      * @return \stdClass[]
      */
     public function get_selectable_options(): array {
-        $selectableOptions = [];
+        $selectableoptions = [];
         foreach ($this->options as $option) {
             if ($option['value'] !== $this->selected && !$option['disabled']) {
-                $selectableOptions[] = (object) $option;
+                $selectableoptions[] = (object) $option;
             }
         }
-        return $selectableOptions;
+        return $selectableoptions;
     }
 
     /**
diff --git a/lib/classes/output/chooser.php b/lib/classes/output/chooser.php
index 268e4285c43..0f7c86df65a 100644
--- a/lib/classes/output/chooser.php
+++ b/lib/classes/output/chooser.php
@@ -36,7 +36,6 @@ use stdClass;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class chooser implements renderable, templatable {
-
     /** @var moodle_url The form action URL. */
     public $actionurl;
     /** @var lang_string The instructions to display. */
@@ -81,7 +80,7 @@ class chooser implements renderable, templatable {
         $this->params[] = [
             'name' => $name,
             'value' => $value,
-            'id' => $id
+            'id' => $id,
         ];
     }
 
@@ -120,11 +119,10 @@ class chooser implements renderable, templatable {
         $data->sesskey = sesskey();
         $data->title = (string) $this->title;
 
-        $data->sections = array_map(function($section) use ($output) {
+        $data->sections = array_map(function ($section) use ($output) {
             return $section->export_for_template($output);
         }, $this->sections);
 
         return $data;
     }
-
 }
diff --git a/lib/classes/output/chooser_item.php b/lib/classes/output/chooser_item.php
index e1a7e99281a..c90d6f115b8 100644
--- a/lib/classes/output/chooser_item.php
+++ b/lib/classes/output/chooser_item.php
@@ -36,7 +36,6 @@ use stdClass;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class chooser_item implements renderable, templatable {
-
     /** @var string An identifier for the item. */
     public $id;
     /** @var string The label of this item. */
@@ -89,11 +88,17 @@ class chooser_item implements renderable, templatable {
 
         $data->description = '';
         if (!empty($this->description)) {
-            list($data->description) = \core_external\util::format_text((string) $this->description, FORMAT_MARKDOWN,
-                $this->context->id, null, null, null, $options);
+            [$data->description] = \core_external\util::format_text(
+                (string) $this->description,
+                FORMAT_MARKDOWN,
+                $this->context->id,
+                null,
+                null,
+                null,
+                $options
+            );
         }
 
         return $data;
     }
-
 }
diff --git a/lib/classes/output/chooser_section.php b/lib/classes/output/chooser_section.php
index ed071058cc0..b4e85d24581 100644
--- a/lib/classes/output/chooser_section.php
+++ b/lib/classes/output/chooser_section.php
@@ -35,7 +35,6 @@ use stdClass;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class chooser_section implements renderable, templatable {
-
     /** @var string $id An identifier for the section. */
     public $id;
     /** @var lang_string $label The label of the section. */
@@ -66,10 +65,9 @@ class chooser_section implements renderable, templatable {
         $data = new stdClass();
         $data->id = $this->id;
         $data->label = (string) $this->label;
-        $data->items = array_map(function($item) use ($output) {
+        $data->items = array_map(function ($item) use ($output) {
             return $item->export_for_template($output);
         }, array_values($this->items));
         return $data;
     }
-
 }
diff --git a/lib/classes/output/comboboxsearch.php b/lib/classes/output/comboboxsearch.php
index b8ec7ea8b79..f0120c8874a 100644
--- a/lib/classes/output/comboboxsearch.php
+++ b/lib/classes/output/comboboxsearch.php
@@ -21,12 +21,11 @@ use core\exception\moodle_exception;
 /**
  * Renderable class for the comboboxsearch.
  *
- * @package    core_output
+ * @package    core
  * @copyright  2022 Mathew May <Mathew.solutions>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class comboboxsearch implements renderable, templatable {
-
     /** @var bool $renderlater Should the dropdown render straightaway? We sometimes need to output the component without all of the
      * data and leave the rendering of any defaults and actual data to the caller. We will give you a basic placeholder that can
      * then be easily replaced.*/
@@ -50,7 +49,7 @@ class comboboxsearch implements renderable, templatable {
     /** @var null|string $buttonheader If the button item in the tertiary nav needs an extra top header for context. */
     protected $buttonheader;
 
-    /** @var boolean $usesbutton Whether to provide a A11y button. */
+    /** @var bool $usesbutton Whether to provide a A11y button. */
     protected $usesbutton;
 
     /** @var null|string $label The label of the combobox. */
@@ -96,15 +95,16 @@ class comboboxsearch implements renderable, templatable {
             throw new moodle_exception(
                 'incorrectdropdownvars',
                 'core',
-                '', null,
+                '',
+                null,
                 'Dropdown content must be set to render later.'
             );
         }
 
         if ($usebutton && !$label) {
             debugging(
-                    'You have requested to use the button but have not provided a label for the combobox.',
-                    DEBUG_DEVELOPER
+                'You have requested to use the button but have not provided a label for the combobox.',
+                DEBUG_DEVELOPER
             );
         }
 
@@ -137,7 +137,7 @@ class comboboxsearch implements renderable, templatable {
     public function export_for_template(renderer_base $output): array {
         return [
             'renderlater' => $this->renderlater,
-            'buttoncontent' => $this->buttoncontent ,
+            'buttoncontent' => $this->buttoncontent,
             'dropdowncontent' => $this->dropdowncontent,
             'parentclasses' => $this->parentclasses,
             'buttonclasses' => $this->buttonclasses,
diff --git a/lib/classes/output/context_header.php b/lib/classes/output/context_header.php
index fc6a056118f..b3030ced3af 100644
--- a/lib/classes/output/context_header.php
+++ b/lib/classes/output/context_header.php
@@ -26,18 +26,15 @@ namespace core\output;
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class context_header implements renderable, templatable {
-/**
-     * @var string $heading Main heading.
-     */
+    /** @var string $heading Main heading */
     public $heading;
-    /**
-     * @var int $headinglevel Main heading 'h' tag level.
-     */
+
+    /** @var int $headinglevel Main heading 'h' tag level */
     public $headinglevel;
-    /**
-     * @var string|null $imagedata HTML code for the picture in the page header.
-     */
+
+    /** @var string|null $imagedata HTML code for the picture in the page header */
     public $imagedata;
+
     /**
      * @var array $additionalbuttons Additional buttons for the header e.g. Messaging button for the user header.
      *      array elements - title => alternate text for the image, or if no image is available the button text.
@@ -47,9 +44,8 @@ class context_header implements renderable, templatable {
      *                       page => page object. Don't include if the image is an external image.
      */
     public $additionalbuttons;
-    /**
-     * @var string $prefix A string that is before the title.
-     */
+
+    /** @var string $prefix A string that is before the title */
     public $prefix;
 
     /**
@@ -62,7 +58,6 @@ class context_header implements renderable, templatable {
      * @param string $prefix Text that precedes the heading.
      */
     public function __construct($heading = null, $headinglevel = 1, $imagedata = null, $additionalbuttons = null, $prefix = null) {
-
         $this->heading = $heading;
         $this->headinglevel = $headinglevel;
         $this->imagedata = $imagedata;
@@ -101,8 +96,10 @@ class context_header implements renderable, templatable {
                 $class = 'btn';
             }
             // Add the bootstrap 'btn' class for formatting.
-            $this->additionalbuttons[$buttontype]['linkattributes'] = array_merge($button['linkattributes'],
-                array('class' => $class));
+            $this->additionalbuttons[$buttontype]['linkattributes'] = array_merge(
+                $button['linkattributes'],
+                ['class' => $class]
+            );
         }
     }
 
diff --git a/lib/classes/output/core_renderer.php b/lib/classes/output/core_renderer.php
index 038ef4a7c5d..e56a8dbeeea 100644
--- a/lib/classes/output/core_renderer.php
+++ b/lib/classes/output/core_renderer.php
@@ -69,36 +69,36 @@ class core_renderer extends renderer_base {
      * Do NOT use, please use <?php echo $OUTPUT->main_content() ?>
      * in layout files instead.
      * @deprecated
-     * @var string used in {@link core_renderer::header()}.
+     * @var string used in {@see core_renderer::header()}.
      */
     const MAIN_CONTENT_TOKEN = '[MAIN CONTENT GOES HERE]';
 
     /**
-     * @var string Used to pass information from {@link core_renderer::doctype()} to
-     * {@link core_renderer::standard_head_html()}.
+     * @var string Used to pass information from {@see core_renderer::doctype()} to
+     * @see core_renderer::standard_head_html()
      */
     protected $contenttype;
 
     /**
-     * @var string Used by {@link core_renderer::redirect_message()} method to communicate
-     * with {@link core_renderer::header()}.
+     * @var string Used by {@see core_renderer::redirect_message()} method to communicate
+     * with {@see core_renderer::header()}.
      */
     protected $metarefreshtag = '';
 
     /**
      * @var string Unique token for the closing HTML
      */
-    protected $unique_end_html_token;
+    protected $unique_end_html_token; // phpcs:ignore moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
 
     /**
      * @var string Unique token for performance information
      */
-    protected $unique_performance_info_token;
+    protected $unique_performance_info_token; // phpcs:ignore moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
 
     /**
      * @var string Unique token for the main content.
      */
-    protected $unique_main_content_token;
+    protected $unique_main_content_token; // phpcs:ignore moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
 
     /** @var custom_menu_item language The language menu if created */
     protected $language = null;
@@ -120,9 +120,9 @@ class core_renderer extends renderer_base {
         $this->page = $page;
         $this->target = $target;
 
-        $this->unique_end_html_token = '%%ENDHTML-'.sesskey().'%%';
-        $this->unique_performance_info_token = '%%PERFORMANCEINFO-'.sesskey().'%%';
-        $this->unique_main_content_token = '[MAIN CONTENT GOES HERE - '.sesskey().']';
+        $this->unique_end_html_token = '%%ENDHTML-' . sesskey() . '%%';
+        $this->unique_performance_info_token = '%%PERFORMANCEINFO-' . sesskey() . '%%';
+        $this->unique_main_content_token = '[MAIN CONTENT GOES HERE - ' . sesskey() . ']';
     }
 
     /**
@@ -135,11 +135,9 @@ class core_renderer extends renderer_base {
         if ($this->page->theme->doctype === 'html5') {
             $this->contenttype = 'text/html; charset=utf-8';
             return "<!DOCTYPE html>\n";
-
         } else if ($this->page->theme->doctype === 'xhtml5') {
             $this->contenttype = 'application/xhtml+xml; charset=utf-8';
             return "<!DOCTYPE html>\n";
-
         } else {
             // legacy xhtml 1.0
             $this->contenttype = 'text/html; charset=utf-8';
@@ -207,16 +205,16 @@ class core_renderer extends renderer_base {
 
         $hook->add_html('<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />' . "\n");
         $hook->add_html('<meta name="keywords" content="moodle, ' . $this->page->title . '" />' . "\n");
-        // This is only set by the {@link redirect()} method
+        // This is only set by the {@see redirect()} method
         $hook->add_html($this->metarefreshtag);
 
         // Check if a periodic refresh delay has been set and make sure we arn't
         // already meta refreshing
-        if ($this->metarefreshtag=='' && $this->page->periodicrefreshdelay!==null) {
+        if ($this->metarefreshtag == '' && $this->page->periodicrefreshdelay !== null) {
             $hook->add_html(
                 html_writer::empty_tag('meta', [
                     'http-equiv' => 'refresh',
-                    'content' => $this->page->periodicrefreshdelay . ';url='.$this->page->url->out(),
+                    'content' => $this->page->periodicrefreshdelay . ';url=' . $this->page->url->out(),
                 ]),
             );
         }
@@ -231,14 +229,14 @@ class core_renderer extends renderer_base {
             if (preg_match("#forms\['([a-zA-Z0-9]+)'\].elements\['([a-zA-Z0-9]+)'\]#", $focus, $matches)) {
                 // This is a horrifically bad way to handle focus but it is passed in
                 // through messy formslib::moodleform
-                $this->page->requires->js_function_call('old_onload_focus', array($matches[1], $matches[2]));
-            } else if (strpos($focus, '.')!==false) {
+                $this->page->requires->js_function_call('old_onload_focus', [$matches[1], $matches[2]]);
+            } else if (strpos($focus, '.') !== false) {
                 // Old style of focus, bad way to do it
                 debugging('This code is using the old style focus event, Please update this code to focus on an element id or the moodleform focus method.', DEBUG_DEVELOPER);
                 $this->page->requires->js_function_call('old_onload_focus', explode('.', $focus, 2));
             } else {
                 // Focus element with given id
-                $this->page->requires->js_function_call('focuscontrol', array($focus));
+                $this->page->requires->js_function_call('focuscontrol', [$focus]);
             }
         }
 
@@ -262,13 +260,17 @@ class core_renderer extends renderer_base {
 
         // List alternate versions.
         foreach ($this->page->alternateversions as $type => $alt) {
-            $output .= html_writer::empty_tag('link', array('rel' => 'alternate',
-                    'type' => $type, 'title' => $alt->title, 'href' => $alt->url));
+            $output .= html_writer::empty_tag('link', [
+                'rel' => 'alternate',
+                'type' => $type,
+                'title' => $alt->title,
+                'href' => $alt->url,
+            ]);
         }
 
         // Add noindex tag if relevant page and setting applied.
         $allowindexing = isset($CFG->allowindexing) ? $CFG->allowindexing : 0;
-        $loginpages = array('login-index', 'login-signup');
+        $loginpages = ['login-index', 'login-signup'];
         if ($allowindexing == 2 || ($allowindexing == 0 && in_array($this->page->pagetype, $loginpages))) {
             if (!isset($CFG->additionalhtmlhead)) {
                 $CFG->additionalhtmlhead = '';
@@ -277,7 +279,7 @@ class core_renderer extends renderer_base {
         }
 
         if (!empty($CFG->additionalhtmlhead)) {
-            $output .= "\n".$CFG->additionalhtmlhead;
+            $output .= "\n" . $CFG->additionalhtmlhead;
         }
 
         if ($this->page->pagelayout == 'frontpage') {
@@ -300,7 +302,7 @@ class core_renderer extends renderer_base {
         global $CFG;
         $output = $this->page->requires->get_top_of_body_code($this);
         if ($this->page->pagelayout !== 'embedded' && !empty($CFG->additionalhtmltopofbody)) {
-            $output .= "\n".$CFG->additionalhtmltopofbody;
+            $output .= "\n" . $CFG->additionalhtmltopofbody;
         }
 
         // Allow components to add content to the top of the body.
@@ -342,11 +344,15 @@ class core_renderer extends renderer_base {
             }
 
             $output .= $this->box_end();
-            $this->page->requires->yui_module('moodle-core-maintenancemodetimer', 'M.core.maintenancemodetimer',
-                    array(array('timeleftinsec' => $timeleft)));
+            $this->page->requires->yui_module(
+                'moodle-core-maintenancemodetimer',
+                'M.core.maintenancemodetimer',
+                [['timeleftinsec' => $timeleft]]
+            );
             $this->page->requires->strings_for_js(
-                    array('maintenancemodeisscheduled', 'maintenancemodeisscheduledlong', 'sitemaintenance'),
-                    'admin');
+                ['maintenancemodeisscheduled', 'maintenancemodeisscheduledlong', 'sitemaintenance'],
+                'admin'
+            );
         }
         return $output;
     }
@@ -371,7 +377,7 @@ class core_renderer extends renderer_base {
 
         if ($this->page->devicetypeinuse == 'legacy') {
             // The legacy theme is in use print the notification
-            $output .= html_writer::tag('div', get_string('legacythemeinuse'), array('class'=>'legacythemeinuse'));
+            $output .= html_writer::tag('div', get_string('legacythemeinuse'), ['class' => 'legacythemeinuse']);
         }
 
         // Get links to switch device types (only shown for users not on a default device)
@@ -400,21 +406,26 @@ class core_renderer extends renderer_base {
         $output .= $this->unique_performance_info_token;
 
         if (!empty($CFG->debugpageinfo)) {
-            $output .= '<div class="performanceinfo pageinfo">' . get_string('pageinfodebugsummary', 'core_admin',
-                $this->page->debug_summary()) . '</div>';
+            $output .= '<div class="performanceinfo pageinfo">' . get_string(
+                'pageinfodebugsummary',
+                'core_admin',
+                $this->page->debug_summary()
+            ) . '</div>';
         }
         if (debugging(null, DEBUG_DEVELOPER) and has_capability('moodle/site:config', context_system::instance())) {  // Only in developer mode
-
             // Add link to profiling report if necessary
             if (function_exists('profiling_is_running') && profiling_is_running()) {
                 $txt = get_string('profiledscript', 'admin');
                 $title = get_string('profiledscriptview', 'admin');
                 $url = $CFG->wwwroot . '/admin/tool/profiling/index.php?script=' . urlencode($SCRIPT);
-                $link= '<a title="' . $title . '" href="' . $url . '">' . $txt . '</a>';
+                $link = '<a title="' . $title . '" href="' . $url . '">' . $txt . '</a>';
                 $output .= '<div class="profilingfooter">' . $link . '</div>';
             }
-            $purgeurl = new moodle_url('/admin/purgecaches.php', array('confirm' => 1,
-                'sesskey' => sesskey(), 'returnurl' => $this->page->url->out_as_local_url(false)));
+            $purgeurl = new moodle_url('/admin/purgecaches.php', [
+                'confirm' => 1,
+                'sesskey' => sesskey(),
+                'returnurl' => $this->page->url->out_as_local_url(false),
+            ]);
             $output .= '<div class="purgecaches">' .
                     html_writer::link($purgeurl, get_string('purgecaches', 'admin')) . '</div>';
 
@@ -427,7 +438,7 @@ class core_renderer extends renderer_base {
             $waveurl = new moodle_url('https://wave.webaim.org/report#/' . urlencode($siteurl));
             $validatorlinks = [
                 html_writer::link($nuurl, get_string('validatehtml')),
-                html_writer::link($waveurl, get_string('wcagcheck'))
+                html_writer::link($waveurl, get_string('wcagcheck')),
             ];
             $validatorlinkslist = html_writer::alist($validatorlinks, ['class' => 'list-unstyled ml-1']);
             $output .= html_writer::div($validatorlinkslist, 'validators');
@@ -448,7 +459,7 @@ class core_renderer extends renderer_base {
         // This is an unfortunate hack. DO NO EVER add anything more here.
         // DO NOT add classes.
         // DO NOT add an id.
-        return '<div role="main">'.$this->unique_main_content_token.'</div>';
+        return '<div role="main">' . $this->unique_main_content_token . '</div>';
     }
 
     /**
@@ -481,8 +492,10 @@ class core_renderer extends renderer_base {
     public function activity_navigation() {
         // First we should check if we want to add navigation.
         $context = $this->page->context;
-        if (($this->page->pagelayout !== 'incourse' && $this->page->pagelayout !== 'frametop')
-            || $context->contextlevel != CONTEXT_MODULE) {
+        if (
+            ($this->page->pagelayout !== 'incourse' && $this->page->pagelayout !== 'frametop')
+            || $context->contextlevel != CONTEXT_MODULE
+        ) {
             return '';
         }
 
@@ -496,8 +509,10 @@ class core_renderer extends renderer_base {
 
         // If the theme implements course index and the current course format uses course index and the current
         // page layout is not 'frametop' (this layout does not support course index), show no links.
-        if ($this->page->theme->usescourseindex && $courseformat->uses_course_index() &&
-                $this->page->pagelayout !== 'frametop') {
+        if (
+            $this->page->theme->usescourseindex && $courseformat->uses_course_index() &&
+                $this->page->pagelayout !== 'frametop'
+        ) {
             return '';
         }
 
@@ -525,7 +540,7 @@ class core_renderer extends renderer_base {
                 $modname .= ' ' . get_string('hiddenwithbrackets');
             }
             // Module URL.
-            $linkurl = new moodle_url($module->url, array('forceview' => 1));
+            $linkurl = new moodle_url($module->url, ['forceview' => 1]);
             // Add module URL (as key) and name (as value) to the activity list array.
             $activitylist[$linkurl->out(false)] = $modname;
         }
@@ -570,12 +585,12 @@ class core_renderer extends renderer_base {
     public function standard_end_of_body_html() {
         global $CFG;
 
-        // This function is normally called from a layout.php file in {@link core_renderer::header()}
+        // This function is normally called from a layout.php file in {@see core_renderer::header()}
         // but some of the content won't be known until later, so we return a placeholder
-        // for now. This will be replaced with the real content in {@link core_renderer::footer()}.
+        // for now. This will be replaced with the real content in {@see core_renderer::footer()}.
         $output = '';
         if ($this->page->pagelayout !== 'embedded' && !empty($CFG->additionalhtmlfooter)) {
-            $output .= "\n".$CFG->additionalhtmlfooter;
+            $output .= "\n" . $CFG->additionalhtmlfooter;
         }
         $output .= $this->unique_end_html_token;
         return $output;
@@ -628,8 +643,8 @@ class core_renderer extends renderer_base {
             $fullname = fullname($realuser);
             if ($withlinks) {
                 $loginastitle = get_string('loginas');
-                $realuserinfo = " [<a href=\"$CFG->wwwroot/course/loginas.php?id=$course->id&amp;sesskey=".sesskey()."\"";
-                $realuserinfo .= "title =\"".$loginastitle."\">$fullname</a>] ";
+                $realuserinfo = " [<a href=\"$CFG->wwwroot/course/loginas.php?id=$course->id&amp;sesskey=" . sesskey() . "\"";
+                $realuserinfo .= "title =\"" . $loginastitle . "\">$fullname</a>] ";
             } else {
                 $realuserinfo = " [$fullname] ";
             }
@@ -654,7 +669,7 @@ class core_renderer extends renderer_base {
             } else {
                 $username = $fullname;
             }
-            if (is_mnet_remote_user($USER) and $idprovider = $DB->get_record('mnet_host', array('id'=>$USER->mnethostid))) {
+            if (is_mnet_remote_user($USER) and $idprovider = $DB->get_record('mnet_host', ['id' => $USER->mnethostid])) {
                 if ($withlinks) {
                     $username .= " from <a href=\"{$idprovider->wwwroot}\">{$idprovider->name}</a>";
                 } else {
@@ -662,34 +677,34 @@ class core_renderer extends renderer_base {
                 }
             }
             if (isguestuser()) {
-                $loggedinas = $realuserinfo.get_string('loggedinasguest');
+                $loggedinas = $realuserinfo . get_string('loggedinasguest');
                 if (!$loginpage && $withlinks) {
-                    $loggedinas .= " (<a href=\"$loginurl\">".get_string('login').'</a>)';
+                    $loggedinas .= " (<a href=\"$loginurl\">" . get_string('login') . '</a>)';
                 }
             } else if (is_role_switched($course->id)) { // Has switched roles
                 $rolename = '';
-                if ($role = $DB->get_record('role', array('id'=>$USER->access['rsw'][$context->path]))) {
-                    $rolename = ': '.role_get_name($role, $context);
+                if ($role = $DB->get_record('role', ['id' => $USER->access['rsw'][$context->path]])) {
+                    $rolename = ': ' . role_get_name($role, $context);
                 }
-                $loggedinas = get_string('loggedinas', 'moodle', $username).$rolename;
+                $loggedinas = get_string('loggedinas', 'moodle', $username) . $rolename;
                 if ($withlinks) {
-                    $url = new moodle_url('/course/switchrole.php', array('id'=>$course->id,'sesskey'=>sesskey(), 'switchrole'=>0, 'returnurl'=>$this->page->url->out_as_local_url(false)));
-                    $loggedinas .= ' ('.html_writer::tag('a', get_string('switchrolereturn'), array('href' => $url)).')';
+                    $url = new moodle_url('/course/switchrole.php', ['id' => $course->id, 'sesskey' => sesskey(), 'switchrole' => 0, 'returnurl' => $this->page->url->out_as_local_url(false)]);
+                    $loggedinas .= ' (' . html_writer::tag('a', get_string('switchrolereturn'), ['href' => $url]) . ')';
                 }
             } else {
-                $loggedinas = $realuserinfo.get_string('loggedinas', 'moodle', $username);
+                $loggedinas = $realuserinfo . get_string('loggedinas', 'moodle', $username);
                 if ($withlinks) {
-                    $loggedinas .= " (<a href=\"$CFG->wwwroot/login/logout.php?sesskey=".sesskey()."\">".get_string('logout').'</a>)';
+                    $loggedinas .= " (<a href=\"$CFG->wwwroot/login/logout.php?sesskey=" . sesskey() . "\">" . get_string('logout') . '</a>)';
                 }
             }
         } else {
             $loggedinas = get_string('loggedinnot', 'moodle');
             if (!$loginpage && $withlinks) {
-                $loggedinas .= " (<a href=\"$loginurl\">".get_string('login').'</a>)';
+                $loggedinas .= " (<a href=\"$loginurl\">" . get_string('login') . '</a>)';
             }
         }
 
-        $loggedinas = '<div class="logininfo">'.$loggedinas.'</div>';
+        $loggedinas = '<div class="logininfo">' . $loggedinas . '</div>';
 
         if (isset($SESSION->justloggedin)) {
             unset($SESSION->justloggedin);
@@ -702,8 +717,11 @@ class core_renderer extends renderer_base {
                     $a->attempts = $count;
                     $loggedinas .= get_string('failedloginattempts', '', $a);
                     if (file_exists("$CFG->dirroot/report/log/index.php") and has_capability('report/log:view', context_system::instance())) {
-                        $loggedinas .= ' ('.html_writer::link(new moodle_url('/report/log/index.php', array('chooselog' => 1,
-                                'id' => 0 , 'modid' => 'site_errors')), get_string('logs')).')';
+                        $loggedinas .= ' (' . html_writer::link(new moodle_url('/report/log/index.php', [
+                            'chooselog' => 1,
+                            'id' => 0,
+                            'modid' => 'site_errors',
+                        ]), get_string('logs')) . ')';
                     }
                     $loggedinas .= '</div>';
                 }
@@ -724,11 +742,11 @@ class core_renderer extends renderer_base {
         // In fact the login pages should be only these two pages and as exposing this as an option for all pages
         // could lead to abuse (or at least unneedingly complex code) the hack is the way to go.
         return in_array(
-            $this->page->url->out_as_local_url(false, array()),
-            array(
+            $this->page->url->out_as_local_url(false, []),
+            [
                 '/login/index.php',
                 '/login/forgot_password.php',
-            )
+            ]
         );
     }
 
@@ -744,21 +762,18 @@ class core_renderer extends renderer_base {
             // Special case for site home page - please do not remove
             return '<div class="sitelink">' .
                    '<a title="Moodle" class="d-inline-block aalink" href="http://moodle.org/">' .
-                   '<img src="' . $this->image_url('moodlelogo_grayhat') . '" alt="'.get_string('moodlelogo').'" /></a></div>';
-
+                   '<img src="' . $this->image_url('moodlelogo_grayhat') . '" alt="' . get_string('moodlelogo') . '" /></a></div>';
         } else if (!empty($CFG->target_release) && $CFG->target_release != $CFG->release) {
             // Special case for during install/upgrade.
-            return '<div class="sitelink">'.
+            return '<div class="sitelink">' .
                    '<a title="Moodle" href="http://docs.moodle.org/en/Administrator_documentation" onclick="this.target=\'_blank\'">' .
-                   '<img src="' . $this->image_url('moodlelogo_grayhat') . '" alt="'.get_string('moodlelogo').'" /></a></div>';
-
+                   '<img src="' . $this->image_url('moodlelogo_grayhat') . '" alt="' . get_string('moodlelogo') . '" /></a></div>';
         } else if ($this->page->course->id == $SITE->id || strpos($this->page->pagetype, 'course-view') === 0) {
             return '<div class="homelink"><a href="' . $CFG->wwwroot . '/">' .
                     get_string('home') . '</a></div>';
-
         } else {
             return '<div class="homelink"><a href="' . $CFG->wwwroot . '/course/view.php?id=' . $this->page->course->id . '">' .
-                    format_string($this->page->course->shortname, true, array('context' => $this->page->context)) . '</a></div>';
+                    format_string($this->page->course->shortname, true, ['context' => $this->page->context]) . '</a></div>';
         }
     }
 
@@ -783,7 +798,6 @@ class core_renderer extends renderer_base {
      * @return string The HTML to display to the user before dying, may contain
      *         meta refresh, javascript refresh, and may have set header redirects
      */
-
     public function redirect_message(
         $encodedurl,
         $message,
@@ -795,36 +809,36 @@ class core_renderer extends renderer_base {
         $url = str_replace('&amp;', '&', $encodedurl);
 
         switch ($this->page->state) {
-            case moodle_page::STATE_BEFORE_HEADER :
+            case moodle_page::STATE_BEFORE_HEADER:
                 // No output yet it is safe to delivery the full arsenal of redirect methods
                 if (!$debugdisableredirect) {
                     // Don't use exactly the same time here, it can cause problems when both redirects fire at the same time.
-                    $this->metarefreshtag = '<meta http-equiv="refresh" content="'. $delay .'; url='. $encodedurl .'" />'."\n";
-                    $this->page->requires->js_function_call('document.location.replace', array($url), false, ($delay + 3));
+                    $this->metarefreshtag = '<meta http-equiv="refresh" content="' . $delay . '; url=' . $encodedurl . '" />' . "\n";
+                    $this->page->requires->js_function_call('document.location.replace', [$url], false, ($delay + 3));
                 }
                 $output = $this->header();
                 break;
-            case moodle_page::STATE_PRINTING_HEADER :
+            case moodle_page::STATE_PRINTING_HEADER:
                 // We should hopefully never get here
                 throw new coding_exception('You cannot redirect while printing the page header');
                 break;
-            case moodle_page::STATE_IN_BODY :
+            case moodle_page::STATE_IN_BODY:
                 // We really shouldn't be here but we can deal with this
                 debugging("You should really redirect before you start page output");
                 if (!$debugdisableredirect) {
-                    $this->page->requires->js_function_call('document.location.replace', array($url), false, $delay);
+                    $this->page->requires->js_function_call('document.location.replace', [$url], false, $delay);
                 }
                 $output = $this->opencontainers->pop_all_but_last();
                 break;
-            case moodle_page::STATE_DONE :
+            case moodle_page::STATE_DONE:
                 // Too late to be calling redirect now
                 throw new coding_exception('You cannot redirect after the entire page has been generated');
                 break;
         }
         $output .= $this->notification($message, $messagetype);
-        $output .= '<div class="continuebutton">(<a href="'. $encodedurl .'">'. get_string('continue') .'</a>)</div>';
+        $output .= '<div class="continuebutton">(<a href="' . $encodedurl . '">' . get_string('continue') . '</a>)</div>';
         if ($debugdisableredirect) {
-            $output .= '<p><strong>'.get_string('erroroutput', 'error').'</strong></p>';
+            $output .= '<p><strong>' . get_string('erroroutput', 'error') . '</strong></p>';
         }
         $output .= $this->footer();
         return $output;
@@ -896,8 +910,10 @@ class core_renderer extends renderer_base {
         }
 
         // If this theme version is below 2.4 release and this is a course view page
-        if ((!isset($this->page->theme->settings->version) || $this->page->theme->settings->version < 2012101500) &&
-                $this->page->pagelayout === 'course' && $this->page->url->compare(new moodle_url('/course/view.php'), URL_MATCH_BASE)) {
+        if (
+            (!isset($this->page->theme->settings->version) || $this->page->theme->settings->version < 2012101500) &&
+                $this->page->pagelayout === 'course' && $this->page->url->compare(new moodle_url('/course/view.php'), URL_MATCH_BASE)
+        ) {
             // check if course content header/footer have not been output during render of theme layout
             $coursecontentheader = $this->course_content_header(true);
             $coursecontentfooter = $this->course_content_footer(true);
@@ -908,7 +924,7 @@ class core_renderer extends renderer_base {
                 // Besides the content header and footer are not displayed on any other course page
                 debugging('The current theme is not optimised for 2.4, the course-specific header and footer defined in course format will not be output', DEBUG_DEVELOPER);
                 $header .= $coursecontentheader;
-                $footer = $coursecontentfooter. $footer;
+                $footer = $coursecontentfooter . $footer;
             }
         }
 
@@ -981,12 +997,14 @@ class core_renderer extends renderer_base {
                     // If the output buffer was off then we render a placeholder and stream the
                     // performance debugging into it at the very end in the shutdown handler.
                     $PERF->perfdebugdeferred = true;
-                    $performanceinfo .= html_writer::tag('div',
+                    $performanceinfo .= html_writer::tag(
+                        'div',
                         get_string('perfdebugdeferred', 'admin'),
                         [
                             'id' => 'perfdebugfooter',
                             'style' => 'min-height: 30em',
-                        ]);
+                        ]
+                    );
                 } else {
                     $perf = get_performance_info();
                     $performanceinfo = $perf['html'];
@@ -1002,10 +1020,10 @@ class core_renderer extends renderer_base {
 
         // Only show notifications when the current page has a context id.
         if (!empty($this->page->context->id)) {
-            $this->page->requires->js_call_amd('core/notification', 'init', array(
+            $this->page->requires->js_call_amd('core/notification', 'init', [
                 $this->page->context->id,
-                \core\notification::fetch_as_array($this)
-            ));
+                \core\notification::fetch_as_array($this),
+            ]);
         }
         $footer = str_replace($this->unique_end_html_token, $this->page->requires->get_end_code(), $footer);
 
@@ -1062,19 +1080,19 @@ class core_renderer extends renderer_base {
         $bodynotifications = '';
         foreach ($notifications as $notification) {
             $bodynotifications .= $this->render_from_template(
-                    $notification->get_template_name(),
-                    $notification->export_for_template($this)
-                );
+                $notification->get_template_name(),
+                $notification->export_for_template($this)
+            );
         }
 
-        $output = html_writer::span($bodynotifications, 'notifications', array('id' => 'user-notifications'));
+        $output = html_writer::span($bodynotifications, 'notifications', ['id' => 'user-notifications']);
 
         if ($this->page->course->id == SITEID) {
             // return immediately and do not include /course/lib.php if not necessary
             return $output;
         }
 
-        require_once($CFG->dirroot.'/course/lib.php');
+        require_once($CFG->dirroot . '/course/lib.php');
         $functioncalled = true;
         $courseformat = course_get_format($this->page->course);
         if (($obj = $courseformat->course_content_header()) !== null) {
@@ -1102,7 +1120,7 @@ class core_renderer extends renderer_base {
             return '';
         }
         $functioncalled = true;
-        require_once($CFG->dirroot.'/course/lib.php');
+        require_once($CFG->dirroot . '/course/lib.php');
         $courseformat = course_get_format($this->page->course);
         if (($obj = $courseformat->course_content_footer()) !== null) {
             return html_writer::div($courseformat->get_renderer($this->page)->render($obj), 'course-content-footer');
@@ -1122,7 +1140,7 @@ class core_renderer extends renderer_base {
             // return immediately and do not include /course/lib.php if not necessary
             return '';
         }
-        require_once($CFG->dirroot.'/course/lib.php');
+        require_once($CFG->dirroot . '/course/lib.php');
         $courseformat = course_get_format($this->page->course);
         if (($obj = $courseformat->course_header()) !== null) {
             return $courseformat->get_renderer($this->page)->render($obj);
@@ -1142,7 +1160,7 @@ class core_renderer extends renderer_base {
             // return immediately and do not include /course/lib.php if not necessary
             return '';
         }
-        require_once($CFG->dirroot.'/course/lib.php');
+        require_once($CFG->dirroot . '/course/lib.php');
         $courseformat = course_get_format($this->page->course);
         if (($obj = $courseformat->course_footer()) !== null) {
             return $courseformat->get_renderer($this->page)->render($obj);
@@ -1209,7 +1227,7 @@ class core_renderer extends renderer_base {
     /**
      * Returns lang menu or '', this method also checks forcing of languages in courses.
      *
-     * This function calls {@link core_renderer::render_single_select()} to actually display the language menu.
+     * This function calls {@see core_renderer::render_single_select()} to actually display the language menu.
      *
      * @return string The lang menu HTML or empty string
      */
@@ -1225,8 +1243,8 @@ class core_renderer extends renderer_base {
     /**
      * Output the row of editing icons for a block, as defined by the controls array.
      *
-     * @param array $controls an array like {@link block_contents::$controls}.
-     * @param string $blockid The ID given to the block.
+     * @param array $actions an array like {@see block_contents::$controls}.
+     * @param null|string $blockid The ID given to the block.
      * @return string HTML fragment.
      */
     public function block_controls($actions, $blockid = null) {
@@ -1235,7 +1253,7 @@ class core_renderer extends renderer_base {
         }
         $menu = new action_menu($actions);
         if ($blockid !== null) {
-            $menu->set_owner_selector('#'.$blockid);
+            $menu->set_owner_selector('#' . $blockid);
         }
         $menu->attributes['class'] .= ' block-control-actions commands';
         return $this->render($menu);
@@ -1262,7 +1280,7 @@ class core_renderer extends renderer_base {
             'name' => $name,
             'value' => $value,
             'rows' => $rows,
-            'cols' => $cols
+            'cols' => $cols,
         ];
 
         return $this->render_from_template('core_form/editor_textarea', $context);
@@ -1451,18 +1469,18 @@ class core_renderer extends renderer_base {
      */
     public function list_block_contents($icons, $items) {
         $row = 0;
-        $lis = array();
+        $lis = [];
         foreach ($items as $key => $string) {
-            $item = html_writer::start_tag('li', array('class' => 'r' . $row));
-            if (!empty($icons[$key])) { //test if the content has an assigned icon
-                $item .= html_writer::tag('div', $icons[$key], array('class' => 'icon column c0'));
+            $item = html_writer::start_tag('li', ['class' => 'r' . $row]);
+            if (!empty($icons[$key])) { // test if the content has an assigned icon
+                $item .= html_writer::tag('div', $icons[$key], ['class' => 'icon column c0']);
             }
-            $item .= html_writer::tag('div', $string, array('class' => 'column c1'));
+            $item .= html_writer::tag('div', $string, ['class' => 'column c1']);
             $item .= html_writer::end_tag('li');
             $lis[] = $item;
             $row = 1 - $row; // Flip even/odd.
         }
-        return html_writer::tag('ul', implode("\n", $lis), array('class' => 'unlist'));
+        return html_writer::tag('ul', implode("\n", $lis), ['class' => 'unlist']);
     }
 
     /**
@@ -1475,7 +1493,7 @@ class core_renderer extends renderer_base {
     public function blocks_for_region($region, $fakeblocksonly = false) {
         $blockcontents = $this->page->blocks->get_content_for_region($region, $this);
         $lastblock = null;
-        $zones = array();
+        $zones = [];
         foreach ($blockcontents as $bc) {
             if ($bc instanceof block_contents) {
                 $zones[] = $bc->title;
@@ -1523,23 +1541,23 @@ class core_renderer extends renderer_base {
         } else {
             $position = get_string('moveblockafter', 'block', $previous);
         }
-        return html_writer::tag('a', html_writer::tag('span', $position, array('class' => 'accesshide')), array('href' => $target->url, 'class' => 'blockmovetarget'));
+        return html_writer::tag('a', html_writer::tag('span', $position, ['class' => 'accesshide']), ['href' => $target->url, 'class' => 'blockmovetarget']);
     }
 
     /**
      * Renders a special html link with attached action
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_action_link()} instead.
+     * {@see core_renderer::render_action_link()} instead.
      *
      * @param string|moodle_url $url
      * @param string $text HTML fragment
-     * @param component_action $action
-     * @param array $attributes associative array of html link attributes + disabled
-     * @param pix_icon optional pix icon to render with the link
+     * @param null|component_action $action
+     * @param null|array $attributes associative array of html link attributes + disabled
+     * @param null|pix_icon optional pix icon to render with the link
      * @return string HTML fragment
      */
-    public function action_link($url, $text, component_action $action = null, array $attributes = null, $icon = null) {
+    public function action_link($url, $text, ?component_action $action = null, ?array $attributes = null, $icon = null) {
         if (!($url instanceof moodle_url)) {
             $url = new moodle_url($url);
         }
@@ -1552,7 +1570,7 @@ class core_renderer extends renderer_base {
      * Renders an action_link object.
      *
      * The provided link is renderer and the HTML returned. At the same time the
-     * associated actions are setup in JS by {@link core_renderer::add_action_handler()}
+     * associated actions are setup in JS by {@see core_renderer::add_action_handler()}
      *
      * @param action_link $link
      * @return string HTML fragment
@@ -1564,22 +1582,28 @@ class core_renderer extends renderer_base {
     /**
      * Renders an action_icon.
      *
-     * This function uses the {@link core_renderer::action_link()} method for the
+     * This function uses the {@see core_renderer::action_link()} method for the
      * most part. What it does different is prepare the icon as HTML and use it
      * as the link text.
      *
      * Theme developers: If you want to change how action links and/or icons are rendered,
-     * consider overriding function {@link core_renderer::render_action_link()} and
-     * {@link core_renderer::render_pix_icon()}.
+     * consider overriding function {@see core_renderer::render_action_link()} and
+     * {@see core_renderer::render_pix_icon()}.
      *
      * @param string|moodle_url $url A string URL or moodel_url
      * @param pix_icon $pixicon
-     * @param component_action $action
-     * @param array $attributes associative array of html link attributes + disabled
+     * @param null|component_action $action
+     * @param null|array $attributes associative array of html link attributes + disabled
      * @param bool $linktext show title next to image in link
      * @return string HTML fragment
      */
-    public function action_icon($url, pix_icon $pixicon, component_action $action = null, array $attributes = null, $linktext=false) {
+    public function action_icon(
+        $url,
+        pix_icon $pixicon,
+        ?component_action $action = null,
+        ?array $attributes = null,
+        $linktext = false,
+    ) {
         if (!($url instanceof moodle_url)) {
             $url = new moodle_url($url);
         }
@@ -1603,7 +1627,7 @@ class core_renderer extends renderer_base {
 
         $icon = $this->render($pixicon);
 
-        return $this->action_link($url, $text.$icon, $action, $attributes);
+        return $this->action_link($url, $text . $icon, $action, $attributes);
     }
 
    /**
@@ -1630,11 +1654,19 @@ class core_renderer extends renderer_base {
                 $continue->type = single_button::BUTTON_PRIMARY;
             }
         } else if (is_string($continue)) {
-            $continue = new single_button(new moodle_url($continue), $displayoptions['continuestr'], 'post',
-                $displayoptions['type'] ?? single_button::BUTTON_PRIMARY);
+            $continue = new single_button(
+                new moodle_url($continue),
+                $displayoptions['continuestr'],
+                'post',
+                $displayoptions['type'] ?? single_button::BUTTON_PRIMARY
+            );
         } else if ($continue instanceof moodle_url) {
-            $continue = new single_button($continue, $displayoptions['continuestr'], 'post',
-                $displayoptions['type'] ?? single_button::BUTTON_PRIMARY);
+            $continue = new single_button(
+                $continue,
+                $displayoptions['continuestr'],
+                'post',
+                $displayoptions['type'] ?? single_button::BUTTON_PRIMARY
+            );
         } else {
             throw new coding_exception('The continue param to $OUTPUT->confirm() must be either a URL (string/moodle_url) or a single_button instance.');
         }
@@ -1650,10 +1682,10 @@ class core_renderer extends renderer_base {
         }
 
         $attributes = [
-            'role'=>'alertdialog',
-            'aria-labelledby'=>'modal-header',
-            'aria-describedby'=>'modal-body',
-            'aria-modal'=>'true'
+            'role' => 'alertdialog',
+            'aria-labelledby' => 'modal-header',
+            'aria-describedby' => 'modal-body',
+            'aria-modal' => 'true',
         ];
 
         $output = $this->box_start('generalbox modal modal-dialog modal-in-page show', 'notice', $attributes);
@@ -1662,8 +1694,8 @@ class core_renderer extends renderer_base {
         $output .= html_writer::tag('h4', $displayoptions['confirmtitle']);
         $output .= $this->box_end();
         $attributes = [
-            'role'=>'alert',
-            'data-aria-autofocus'=>'true'
+            'role' => 'alert',
+            'data-aria-autofocus' => 'true',
         ];
         $output .= $this->box_start('modal-body', 'modal-body', $attributes);
         $output .= html_writer::tag('p', $message);
@@ -1680,21 +1712,21 @@ class core_renderer extends renderer_base {
      * Returns a form with a single button.
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_single_button()} instead.
+     * {@see core_renderer::render_single_button()} instead.
      *
      * @param string|moodle_url $url
      * @param string $label button text
      * @param string $method get or post submit method
-     * @param array $options associative array {disabled, title, etc.}
+     * @param null|array $options associative array {disabled, title, etc.}
      * @return string HTML fragment
      */
-    public function single_button($url, $label, $method='post', array $options=null) {
+    public function single_button($url, $label, $method = 'post', ?array $options = null) {
         if (!($url instanceof moodle_url)) {
             $url = new moodle_url($url);
         }
         $button = new single_button($url, $label, $method);
 
-        foreach ((array)$options as $key=>$value) {
+        foreach ((array)$options as $key => $value) {
             if (property_exists($button, $key)) {
                 $button->$key = $value;
             } else {
@@ -1721,7 +1753,7 @@ class core_renderer extends renderer_base {
      * Returns a form with a single select widget.
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_single_select()} instead.
+     * {@see core_renderer::render_single_select()} instead.
      *
      * @param moodle_url $url form action target, includes hidden fields
      * @param string $name name of selection field - the changing parameter in url
@@ -1732,8 +1764,15 @@ class core_renderer extends renderer_base {
      * @param array $attributes other attributes for the single select
      * @return string HTML fragment
      */
-    public function single_select($url, $name, array $options, $selected = '',
-                                $nothing = array('' => 'choosedots'), $formid = null, $attributes = array()) {
+    public function single_select(
+        $url,
+        $name,
+        array $options,
+        $selected = '',
+        $nothing = ['' => 'choosedots'],
+        $formid = null,
+        $attributes = []
+    ) {
         if (!($url instanceof moodle_url)) {
             $url = new moodle_url($url);
         }
@@ -1762,20 +1801,20 @@ class core_renderer extends renderer_base {
         $options = [];
         foreach ($formats as $format) {
             if ($format->is_enabled()) {
-                $options[] = array(
+                $options[] = [
                     'value' => $format->name,
                     'label' => get_string('dataformat', $format->component),
-                );
+                ];
             }
         }
-        $hiddenparams = array();
+        $hiddenparams = [];
         foreach ($params as $key => $value) {
-            $hiddenparams[] = array(
+            $hiddenparams[] = [
                 'name' => $key,
                 'value' => $value,
-            );
+            ];
         }
-        $data = array(
+        $data = [
             'label' => $label,
             'base' => $base,
             'name' => $name,
@@ -1783,7 +1822,7 @@ class core_renderer extends renderer_base {
             'options' => $options,
             'sesskey' => sesskey(),
             'submit' => get_string('download'),
-        );
+        ];
 
         return $this->render_from_template('core/dataformat_selector', $data);
     }
@@ -1803,7 +1842,7 @@ class core_renderer extends renderer_base {
      * Returns a form with a url select widget.
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_url_select()} instead.
+     * {@see core_renderer::render_url_select()} instead.
      *
      * @param array $urls list of urls - array('/course/view.php?id=1'=>'Frontpage', ....)
      * @param string $selected selected element
@@ -1811,7 +1850,7 @@ class core_renderer extends renderer_base {
      * @param string $formid
      * @return string HTML fragment
      */
-    public function url_select(array $urls, $selected, $nothing = array('' => 'choosedots'), $formid = null) {
+    public function url_select(array $urls, $selected, $nothing = ['' => 'choosedots'], $formid = null) {
         $select = new url_select($urls, $selected, $nothing, $formid);
         return $this->render($select);
     }
@@ -1839,14 +1878,18 @@ class core_renderer extends renderer_base {
     public function doc_link($path, $text = '', $forcepopup = false, array $attributes = []) {
         global $CFG;
 
-        $icon = $this->pix_icon('book', '', 'moodle', array('class' => 'iconhelp icon-pre'));
+        $icon = $this->pix_icon('book', '', 'moodle', ['class' => 'iconhelp icon-pre']);
 
         $attributes['href'] = new moodle_url(get_docs_url($path));
         $newwindowicon = '';
         if (!empty($CFG->doctonewwindow) || $forcepopup) {
             $attributes['target'] = '_blank';
-            $newwindowicon = $this->pix_icon('i/externallink', get_string('opensinnewwindow'), 'moodle',
-            ['class' => 'fa fa-externallink fa-fw']);
+            $newwindowicon = $this->pix_icon(
+                'i/externallink',
+                get_string('opensinnewwindow'),
+                'moodle',
+                ['class' => 'fa fa-externallink fa-fw']
+            );
         }
 
         return html_writer::tag('a', $icon . $text . $newwindowicon, $attributes);
@@ -1856,15 +1899,15 @@ class core_renderer extends renderer_base {
      * Return HTML for an image_icon.
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_image_icon()} instead.
+     * {@see core_renderer::render_image_icon()} instead.
      *
      * @param string $pix short pix name
      * @param string $alt mandatory alt attribute
      * @param string $component standard compoennt name like 'moodle', 'mod_forum', etc.
-     * @param array $attributes htm attributes
+     * @param null|array $attributes htm attributes
      * @return string HTML fragment
      */
-    public function image_icon($pix, $alt, $component='moodle', array $attributes = null) {
+    public function image_icon($pix, $alt, $component = 'moodle', ?array $attributes = null) {
         $icon = new image_icon($pix, $alt, $component, $attributes);
         return $this->render($icon);
     }
@@ -1884,15 +1927,15 @@ class core_renderer extends renderer_base {
      * Return HTML for a pix_icon.
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_pix_icon()} instead.
+     * {@see core_renderer::render_pix_icon()} instead.
      *
      * @param string $pix short pix name
      * @param string $alt mandatory alt attribute
      * @param string $component standard compoennt name like 'moodle', 'mod_forum', etc.
-     * @param array $attributes htm lattributes
+     * @param null|array $attributes htm lattributes
      * @return string HTML fragment
      */
-    public function pix_icon($pix, $alt, $component='moodle', array $attributes = null) {
+    public function pix_icon($pix, $alt, $component = 'moodle', ?array $attributes = null) {
         $icon = new pix_icon($pix, $alt, $component, $attributes);
         return $this->render($icon);
     }
@@ -1929,7 +1972,7 @@ class core_renderer extends renderer_base {
         global $CFG, $USER;
 
         if ($rating->settings->aggregationmethod == RATING_AGGREGATE_NONE) {
-            return null;//ratings are turned off
+            return null;// ratings are turned off
         }
 
         $ratingmanager = new rating_manager();
@@ -1937,73 +1980,70 @@ class core_renderer extends renderer_base {
         $ratingmanager->initialise_rating_javascript($this->page);
 
         $strrate = get_string("rate", "rating");
-        $ratinghtml = ''; //the string we'll return
+        $ratinghtml = ''; // the string we'll return
 
         // permissions check - can they view the aggregate?
         if ($rating->user_can_view_aggregate()) {
-
             $aggregatelabel = $ratingmanager->get_aggregate_label($rating->settings->aggregationmethod);
-            $aggregatelabel = html_writer::tag('span', $aggregatelabel, array('class'=>'rating-aggregate-label'));
+            $aggregatelabel = html_writer::tag('span', $aggregatelabel, ['class' => 'rating-aggregate-label']);
             $aggregatestr   = $rating->get_aggregate_string();
 
-            $aggregatehtml  = html_writer::tag('span', $aggregatestr, array('id' => 'ratingaggregate'.$rating->itemid, 'class' => 'ratingaggregate')).' ';
+            $aggregatehtml  = html_writer::tag('span', $aggregatestr, ['id' => 'ratingaggregate' . $rating->itemid, 'class' => 'ratingaggregate']) . ' ';
             if ($rating->count > 0) {
                 $countstr = "({$rating->count})";
             } else {
                 $countstr = '-';
             }
-            $aggregatehtml .= html_writer::tag('span', $countstr, array('id'=>"ratingcount{$rating->itemid}", 'class' => 'ratingcount')).' ';
+            $aggregatehtml .= html_writer::tag('span', $countstr, ['id' => "ratingcount{$rating->itemid}", 'class' => 'ratingcount']) . ' ';
 
             if ($rating->settings->permissions->viewall && $rating->settings->pluginpermissions->viewall) {
-
                 $nonpopuplink = $rating->get_view_ratings_url();
                 $popuplink = $rating->get_view_ratings_url(true);
 
-                $action = new popup_action('click', $popuplink, 'ratings', array('height' => 400, 'width' => 600));
+                $action = new popup_action('click', $popuplink, 'ratings', ['height' => 400, 'width' => 600]);
                 $aggregatehtml = $this->action_link($nonpopuplink, $aggregatehtml, $action);
             }
 
-            $ratinghtml .= html_writer::tag('span', $aggregatelabel . $aggregatehtml, array('class' => 'rating-aggregate-container'));
+            $ratinghtml .= html_writer::tag('span', $aggregatelabel . $aggregatehtml, ['class' => 'rating-aggregate-container']);
         }
 
         $formstart = null;
         // if the item doesn't belong to the current user, the user has permission to rate
         // and we're within the assessable period
         if ($rating->user_can_rate()) {
-
             $rateurl = $rating->get_rate_url();
             $inputs = $rateurl->params();
 
-            //start the rating form
-            $formattrs = array(
+            // start the rating form
+            $formattrs = [
                 'id'     => "postrating{$rating->itemid}",
                 'class'  => 'postratingform',
                 'method' => 'post',
-                'action' => $rateurl->out_omit_querystring()
-            );
+                'action' => $rateurl->out_omit_querystring(),
+            ];
             $formstart  = html_writer::start_tag('form', $formattrs);
-            $formstart .= html_writer::start_tag('div', array('class' => 'ratingform'));
+            $formstart .= html_writer::start_tag('div', ['class' => 'ratingform']);
 
             // add the hidden inputs
             foreach ($inputs as $name => $value) {
-                $attributes = array('type' => 'hidden', 'class' => 'ratinginput', 'name' => $name, 'value' => $value);
+                $attributes = ['type' => 'hidden', 'class' => 'ratinginput', 'name' => $name, 'value' => $value];
                 $formstart .= html_writer::empty_tag('input', $attributes);
             }
 
             if (empty($ratinghtml)) {
-                $ratinghtml .= $strrate.': ';
+                $ratinghtml .= $strrate . ': ';
             }
-            $ratinghtml = $formstart.$ratinghtml;
+            $ratinghtml = $formstart . $ratinghtml;
 
-            $scalearray = array(RATING_UNSET_RATING => $strrate.'...') + $rating->settings->scale->scaleitems;
-            $scaleattrs = array('class'=>'postratingmenu ratinginput','id'=>'menurating'.$rating->itemid);
-            $ratinghtml .= html_writer::label($rating->rating, 'menurating'.$rating->itemid, false, array('class' => 'accesshide'));
+            $scalearray = [RATING_UNSET_RATING => $strrate . '...'] + $rating->settings->scale->scaleitems;
+            $scaleattrs = ['class' => 'postratingmenu ratinginput', 'id' => 'menurating' . $rating->itemid];
+            $ratinghtml .= html_writer::label($rating->rating, 'menurating' . $rating->itemid, false, ['class' => 'accesshide']);
             $ratinghtml .= html_writer::select($scalearray, 'rating', $rating->rating, false, $scaleattrs);
 
-            //output submit button
-            $ratinghtml .= html_writer::start_tag('span', array('class'=>"ratingsubmit"));
+            // output submit button
+            $ratinghtml .= html_writer::start_tag('span', ['class' => "ratingsubmit"]);
 
-            $attributes = array('type' => 'submit', 'class' => 'postratingmenusubmit', 'id' => 'postratingsubmit'.$rating->itemid, 'value' => s(get_string('rate', 'rating')));
+            $attributes = ['type' => 'submit', 'class' => 'postratingmenusubmit', 'id' => 'postratingsubmit' . $rating->itemid, 'value' => s(get_string('rate', 'rating'))];
             $ratinghtml .= html_writer::empty_tag('input', $attributes);
 
             if (!$rating->settings->scale->isnumeric) {
@@ -2039,7 +2079,7 @@ class core_renderer extends renderer_base {
     public function heading_with_help($text, $helpidentifier, $component = 'moodle', $icon = '', $iconalt = '', $level = 2, $classnames = null) {
         $image = '';
         if ($icon) {
-            $image = $this->pix_icon($icon, $iconalt, $component, array('class'=>'icon iconlarge'));
+            $image = $this->pix_icon($icon, $iconalt, $component, ['class' => 'icon iconlarge']);
         }
 
         $help = '';
@@ -2047,7 +2087,7 @@ class core_renderer extends renderer_base {
             $help = $this->help_icon($helpidentifier, $component);
         }
 
-        return $this->heading($image.$text.$help, $level, $classnames);
+        return $this->heading($image . $text . $help, $level, $classnames);
     }
 
     /**
@@ -2063,7 +2103,7 @@ class core_renderer extends renderer_base {
      * Returns HTML to display a help icon.
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_help_icon()} instead.
+     * {@see core_renderer::render_help_icon()} instead.
      *
      * @param string $identifier The keyword that defines a help page
      * @param string $component component name
@@ -2104,27 +2144,27 @@ class core_renderer extends renderer_base {
     public function help_icon_scale($courseid, stdClass $scale) {
         global $CFG;
 
-        $title = get_string('helpprefix2', '', $scale->name) .' ('.get_string('newwindow').')';
+        $title = get_string('helpprefix2', '', $scale->name) . ' (' . get_string('newwindow') . ')';
 
-        $icon = $this->pix_icon('help', get_string('scales'), 'moodle', array('class'=>'iconhelp'));
+        $icon = $this->pix_icon('help', get_string('scales'), 'moodle', ['class' => 'iconhelp']);
 
         $scaleid = abs($scale->id);
 
-        $link = new moodle_url('/course/scales.php', array('id' => $courseid, 'list' => true, 'scaleid' => $scaleid));
+        $link = new moodle_url('/course/scales.php', ['id' => $courseid, 'list' => true, 'scaleid' => $scaleid]);
         $action = new popup_action('click', $link, 'ratingscale');
 
-        return html_writer::tag('span', $this->action_link($link, $icon, $action), array('class' => 'helplink'));
+        return html_writer::tag('span', $this->action_link($link, $icon, $action), ['class' => 'helplink']);
     }
 
     /**
      * Creates and returns a spacer image with optional line break.
      *
-     * @param array $attributes Any HTML attributes to add to the spaced.
+     * @param null|array $attributes Any HTML attributes to add to the spaced.
      * @param bool $br Include a BR after the spacer.... DON'T USE THIS. Don't be
      *     laxy do it with CSS which is a much better solution.
      * @return string HTML fragment
      */
-    public function spacer(array $attributes = null, $br = false) {
+    public function spacer(?array $attributes = null, $br = false) {
         $attributes = (array)$attributes;
         if (empty($attributes['width'])) {
             $attributes['width'] = 1;
@@ -2160,12 +2200,12 @@ class core_renderer extends renderer_base {
      * </pre>
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_user_picture()} instead.
+     * {@see core_renderer::render_user_picture()} instead.
      *
      * @param stdClass $user Object with at least fields id, picture, imagealt, firstname, lastname
      *     If any of these are missing, the database is queried. Avoid this
      *     if at all possible, particularly for reports. It is very bad for performance.
-     * @param array $options associative array with user picture options, used only if not a user_picture object,
+     * @param null|array $options associative array with user picture options, used only if not a user_picture object,
      *     options are:
      *     - courseid=$this->page->course->id (course id of user profile in link)
      *     - size=35 (size of image)
@@ -2178,9 +2218,9 @@ class core_renderer extends renderer_base {
      *     - includetoken = false (whether to use a token for authentication. True for current user, int value for other user id)
      * @return string HTML fragment
      */
-    public function user_picture(stdClass $user, array $options = null) {
+    public function user_picture(stdClass $user, ?array $options = null) {
         $userpicture = new user_picture($user);
-        foreach ((array)$options as $key=>$value) {
+        foreach ((array)$options as $key => $value) {
             if (property_exists($userpicture, $key)) {
                 $userpicture->$key = $value;
             }
@@ -2231,7 +2271,7 @@ class core_renderer extends renderer_base {
 
         $src = $userpicture->get_url($this->page, $this);
 
-        $attributes = array('src' => $src, 'class' => $class, 'width' => $size, 'height' => $size);
+        $attributes = ['src' => $src, 'class' => $class, 'width' => $size, 'height' => $size];
         if (!$userpicture->visibletoscreenreaders) {
             $alt = '';
         }
@@ -2247,7 +2287,8 @@ class core_renderer extends renderer_base {
             $fullname = fullname($userpicture->user, $canviewfullnames);
             // Don't modify in corner cases where neither the firstname nor the lastname appears.
             $output = html_writer::tag(
-                'span', $initials,
+                'span',
+                $initials,
                 [
                     'class' => 'userinitials size-' . $size,
                     'title' => $fullname,
@@ -2270,18 +2311,20 @@ class core_renderer extends renderer_base {
             $courseid = $userpicture->courseid;
         }
         if ($courseid == SITEID) {
-            $url = new moodle_url('/user/profile.php', array('id' => $user->id));
+            $url = new moodle_url('/user/profile.php', ['id' => $user->id]);
         } else {
-            $url = new moodle_url('/user/view.php', array('id' => $user->id, 'course' => $courseid));
+            $url = new moodle_url('/user/view.php', ['id' => $user->id, 'course' => $courseid]);
         }
 
         // Then wrap it in link if needed. Also we don't wrap it in link if the link redirects to itself.
-        if (!$userpicture->link ||
-                ($this->page->has_set_url() && $this->page->url == $url)) { // Protect against unset page->url.
+        if (
+            !$userpicture->link ||
+                ($this->page->has_set_url() && $this->page->url == $url)
+        ) { // Protect against unset page->url.
             return $output;
         }
 
-        $attributes = array('href' => $url, 'class' => 'd-inline-block aabtn');
+        $attributes = ['href' => $url, 'class' => 'd-inline-block aabtn'];
         if (!$userpicture->visibletoscreenreaders) {
             $attributes['tabindex'] = '-1';
             $attributes['aria-hidden'] = 'true';
@@ -2311,7 +2354,7 @@ class core_renderer extends renderer_base {
      * </pre>
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_file_picker()} instead.
+     * {@see core_renderer::render_file_picker()} instead.
      *
      * @param stdClass $options file manager options
      *   options are:
@@ -2342,7 +2385,7 @@ class core_renderer extends renderer_base {
         $strloading  = get_string('loading', 'repository');
         $strdndenabled = get_string('dndenabled_inbox', 'moodle');
         $strdroptoupload = get_string('droptoupload', 'moodle');
-        $iconprogress = $this->pix_icon('i/loading_small', $strloading).'';
+        $iconprogress = $this->pix_icon('i/loading_small', $strloading) . '';
 
         $currentfile = $options->currentfile;
         if (empty($currentfile)) {
@@ -2438,7 +2481,6 @@ EOD;
      */
     public function edit_switch() {
         if ($this->page->user_allowed_editing()) {
-
             $temp = (object) [
                 'legacyseturl' => (new moodle_url('/editmode.php'))->out(false),
                 'pagecontextid' => $this->page->context->id,
@@ -2458,7 +2500,7 @@ EOD;
      * @param string $text The lang string for the button's label (already output from get_string())
      * @return string html fragment
      */
-    public function close_window_button($text='') {
+    public function close_window_button($text = '') {
         if (empty($text)) {
             $text = get_string('closewindow');
         }
@@ -2479,8 +2521,8 @@ EOD;
         if (empty($message)) {
             return '';
         }
-        $message = $this->pix_icon('i/warning', get_string('error'), '', array('class' => 'icon icon-pre', 'title'=>'')) . $message;
-        return html_writer::tag('span', $message, array('class' => 'error'));
+        $message = $this->pix_icon('i/warning', get_string('error'), '', ['class' => 'icon icon-pre', 'title' => '']) . $message;
+        return html_writer::tag('span', $message, ['class' => 'error']);
     }
 
     /**
@@ -2493,7 +2535,8 @@ EOD;
      * @param string $moreinfourl URL where more info can be found about the error
      * @param string $link Link for the Continue button
      * @param array $backtrace The execution backtrace
-     * @param string $debuginfo Debugging information
+     * @param null|string $debuginfo Debugging information
+     * @param string $errorcode
      * @return string the HTML to output.
      */
     public function fatal_error($message, $moreinfourl, $link, $backtrace, $debuginfo = null, $errorcode = "") {
@@ -2506,7 +2549,6 @@ EOD;
             // we can not always recover properly here, we have problems with output buffering,
             // html tables, etc.
             $output .= $this->opencontainers->pop_all_but_last();
-
         } else {
             // It is really bad if library code throws exception when output buffering is on,
             // because the buffered text would be printed before our start of page.
@@ -2536,7 +2578,7 @@ EOD;
 
             $this->page->set_context(null); // ugly hack - make sure page context is set to something, we do not want bogus warnings here
             $this->page->set_url('/'); // no url
-            //$this->page->set_pagelayout('base'); //TODO: MDL-20676 blocks on error pages are weird, unfortunately it somehow detect the pagelayout from URL :-(
+            // $this->page->set_pagelayout('base'); //TODO: MDL-20676 blocks on error pages are weird, unfortunately it somehow detect the pagelayout from URL :-(
             $this->page->set_title(get_string('error'));
             $this->page->set_heading($this->page->course->fullname);
             // No need to display the activity header when encountering an error.
@@ -2544,14 +2586,14 @@ EOD;
             $output .= $this->header();
         }
 
-        $message = '<p class="errormessage">' . s($message) . '</p>'.
+        $message = '<p class="errormessage">' . s($message) . '</p>' .
                 '<p class="errorcode"><a href="' . s($moreinfourl) . '">' .
                 get_string('moreinformation') . '</a></p>';
         if (empty($CFG->rolesactive)) {
             $message .= '<p class="errormessage">' . get_string('installproblem', 'error') . '</p>';
-            //It is usually not possible to recover from errors triggered during installation, you may need to create a new database or use a different database prefix for new installation.
+            // It is usually not possible to recover from errors triggered during installation, you may need to create a new database or use a different database prefix for new installation.
         }
-        $output .= $this->box($message, 'errorbox alert alert-danger', null, array('data-rel' => 'fatalerror'));
+        $output .= $this->box($message, 'errorbox alert alert-danger', null, ['data-rel' => 'fatalerror']);
 
         if ($CFG->debugdeveloper) {
             $labelsep = get_string('labelsep', 'langconfig');
@@ -2565,7 +2607,7 @@ EOD;
                 $label = get_string('stacktrace', 'debug') . $labelsep;
                 $output .= $this->notification("<strong>$label</strong> " . format_backtrace($backtrace), 'notifytiny');
             }
-            if ($obbuffer !== '' ) {
+            if ($obbuffer !== '') {
                 $label = get_string('outputbuffer', 'debug') . $labelsep;
                 $output .= $this->notification("<strong>$label</strong> " . s($obbuffer), 'notifytiny');
             }
@@ -2652,7 +2694,7 @@ EOD;
      * @deprecated since Moodle 3.1 MDL-30811 - please do not use this function any more.
      */
     public function notify_problem() {
-        throw new coding_exception('core_renderer::notify_problem() can not be used any more, '.
+        throw new coding_exception('core_renderer::notify_problem() can not be used any more, ' .
             'please use \core\notification::add(), or \core\output\notification as required.');
     }
 
@@ -2660,7 +2702,7 @@ EOD;
      * @deprecated since Moodle 3.1 MDL-30811 - please do not use this function any more.
      */
     public function notify_success() {
-        throw new coding_exception('core_renderer::notify_success() can not be used any more, '.
+        throw new coding_exception('core_renderer::notify_success() can not be used any more, ' .
             'please use \core\notification::add(), or \core\output\notification as required.');
     }
 
@@ -2668,7 +2710,7 @@ EOD;
      * @deprecated since Moodle 3.1 MDL-30811 - please do not use this function any more.
      */
     public function notify_message() {
-        throw new coding_exception('core_renderer::notify_message() can not be used any more, '.
+        throw new coding_exception('core_renderer::notify_message() can not be used any more, ' .
             'please use \core\notification::add(), or \core\output\notification as required.');
     }
 
@@ -2676,7 +2718,7 @@ EOD;
      * @deprecated since Moodle 3.1 MDL-30811 - please do not use this function any more.
      */
     public function notify_redirect() {
-        throw new coding_exception('core_renderer::notify_redirect() can not be used any more, '.
+        throw new coding_exception('core_renderer::notify_redirect() can not be used any more, ' .
             'please use \core\notification::add(), or \core\output\notification as required.');
     }
 
@@ -2711,7 +2753,7 @@ EOD;
      * Returns HTML to display a single paging bar to provide access to other pages  (usually in a search)
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_paging_bar()} instead.
+     * {@see core_renderer::render_paging_bar()} instead.
      *
      * @param int $totalcount The total number of entries available to be paged through
      * @param int $page The page you are currently viewing
@@ -2771,7 +2813,7 @@ EOD;
      * @return string the HTML to output.
      */
     public function skip_link_target($id = null) {
-        return html_writer::span('', '', array('id' => $id));
+        return html_writer::span('', '', ['id' => $id]);
     }
 
     /**
@@ -2784,11 +2826,11 @@ EOD;
      * @return string the HTML to output.
      */
     public function heading($text, $level = 2, $classes = null, $id = null) {
-        $level = (integer) $level;
+        $level = (int) $level;
         if ($level < 1 or $level > 6) {
             throw new coding_exception('Heading level must be an integer between 1 and 6.');
         }
-        return html_writer::tag('h' . $level, $text, array('id' => $id, 'class' => renderer_base::prepare_classes($classes)));
+        return html_writer::tag('h' . $level, $text, ['id' => $id, 'class' => renderer_base::prepare_classes($classes)]);
     }
 
     /**
@@ -2800,7 +2842,7 @@ EOD;
      * @param array $attributes An array of other attributes to give the box.
      * @return string the HTML to output.
      */
-    public function box($contents, $classes = 'generalbox', $id = null, $attributes = array()) {
+    public function box($contents, $classes = 'generalbox', $id = null, $attributes = []) {
         return $this->box_start($classes, $id, $attributes) . $contents . $this->box_end();
     }
 
@@ -2812,7 +2854,7 @@ EOD;
      * @param array $attributes An array of other attributes to give the box.
      * @return string the HTML to output.
      */
-    public function box_start($classes = 'generalbox', $id = null, $attributes = array()) {
+    public function box_start($classes = 'generalbox', $id = null, $attributes = []) {
         $this->opencontainers->push('box', html_writer::end_tag('div'));
         $attributes['id'] = $id;
         $attributes['class'] = 'box py-3 ' . renderer_base::prepare_classes($classes);
@@ -2913,40 +2955,40 @@ EOD;
      * @param array $attrs html attributes passed to the top ofs the list
      * @return string HTML
      */
-    public function tree_block_contents($items, $attrs = array()) {
+    public function tree_block_contents($items, $attrs = []) {
         // exit if empty, we don't want an empty ul element
         if (empty($items)) {
             return '';
         }
         // array of nested li elements
-        $lis = array();
+        $lis = [];
         foreach ($items as $item) {
             // this applies to the li item which contains all child lists too
             $content = $item->content($this);
-            $liclasses = array($item->get_css_type());
-            if (!$item->forceopen || (!$item->forceopen && $item->collapse) || ($item->children->count()==0  && $item->nodetype==navigation_node::NODETYPE_BRANCH)) {
+            $liclasses = [$item->get_css_type()];
+            if (!$item->forceopen || (!$item->forceopen && $item->collapse) || ($item->children->count() == 0  && $item->nodetype == navigation_node::NODETYPE_BRANCH)) {
                 $liclasses[] = 'collapsed';
             }
             if ($item->isactive === true) {
                 $liclasses[] = 'current_branch';
             }
-            $liattr = array('class'=>join(' ',$liclasses));
+            $liattr = ['class' => join(' ', $liclasses)];
             // class attribute on the div item which only contains the item content
-            $divclasses = array('tree_item');
-            if ($item->children->count()>0  || $item->nodetype==navigation_node::NODETYPE_BRANCH) {
+            $divclasses = ['tree_item'];
+            if ($item->children->count() > 0  || $item->nodetype == navigation_node::NODETYPE_BRANCH) {
                 $divclasses[] = 'branch';
             } else {
                 $divclasses[] = 'leaf';
             }
-            if (!empty($item->classes) && count($item->classes)>0) {
+            if (!empty($item->classes) && count($item->classes) > 0) {
                 $divclasses[] = join(' ', $item->classes);
             }
-            $divattr = array('class'=>join(' ', $divclasses));
+            $divattr = ['class' => join(' ', $divclasses)];
             if (!empty($item->id)) {
                 $divattr['id'] = $item->id;
             }
             $content = html_writer::tag('p', $content, $divattr) . $this->tree_block_contents($item->children);
-            if (!empty($item->preceedwithhr) && $item->preceedwithhr===true) {
+            if (!empty($item->preceedwithhr) && $item->preceedwithhr === true) {
                 $content = html_writer::empty_tag('hr') . $content;
             }
             $content = html_writer::tag('li', $content, $liattr);
@@ -3088,7 +3130,7 @@ EOD;
                         'value'
                     )
                 ),
-                array('class' => 'meta viewingas')
+                ['class' => 'meta viewingas']
             );
         }
 
@@ -3139,7 +3181,6 @@ EOD;
             $navitemcount = count($opts->navitems);
             $idx = 0;
             foreach ($opts->navitems as $key => $value) {
-
                 switch ($value->itemtype) {
                     case 'divider':
                         // If the nav item is a divider, add one and skip link processing.
@@ -3154,12 +3195,12 @@ EOD;
                         // Process this as a link item.
                         $pix = null;
                         if (isset($value->pix) && !empty($value->pix)) {
-                            $pix = new pix_icon($value->pix, '', null, array('class' => 'iconsmall'));
+                            $pix = new pix_icon($value->pix, '', null, ['class' => 'iconsmall']);
                         } else if (isset($value->imgsrc) && !empty($value->imgsrc)) {
                             $value->title = html_writer::img(
                                 $value->imgsrc,
                                 $value->title,
-                                array('class' => 'iconsmall')
+                                ['class' => 'iconsmall']
                             ) . $value->title;
                         }
 
@@ -3167,7 +3208,7 @@ EOD;
                             $value->url,
                             $pix,
                             $value->title,
-                            array('class' => 'icon')
+                            ['class' => 'icon']
                         );
                         if (!empty($value->titleidentifier)) {
                             $al->attributes['data-title'] = $value->titleidentifier;
@@ -3239,7 +3280,7 @@ EOD;
         if ($item->action instanceof moodle_url) {
             $content = $item->get_content();
             $title = $item->get_title();
-            $attributes = array();
+            $attributes = [];
             $attributes['itemprop'] = 'url';
             if ($title !== '') {
                 $attributes['title'] = $title;
@@ -3250,14 +3291,13 @@ EOD;
             if ($item->is_last()) {
                 $attributes['aria-current'] = 'page';
             }
-            $content = html_writer::tag('span', $content, array('itemprop' => 'title'));
+            $content = html_writer::tag('span', $content, ['itemprop' => 'title']);
             $content = html_writer::link($item->action, $content, $attributes);
 
-            $attributes = array();
+            $attributes = [];
             $attributes['itemscope'] = '';
             $attributes['itemtype'] = 'http://data-vocabulary.org/Breadcrumb';
             $content = html_writer::tag('span', $content, $attributes);
-
         } else {
             $content = $this->render_navigation_node($item);
         }
@@ -3275,10 +3315,10 @@ EOD;
         $title = $item->get_title();
         if ($item->icon instanceof renderable && !$item->hideicon) {
             $icon = $this->render($item->icon);
-            $content = $icon.$content; // use CSS for spacing of icons
+            $content = $icon . $content; // use CSS for spacing of icons
         }
         if ($item->helpbutton !== null) {
-            $content = trim($item->helpbutton).html_writer::tag('span', $content, array('class'=>'clearhelpbutton', 'tabindex'=>'0'));
+            $content = trim($item->helpbutton) . html_writer::tag('span', $content, ['class' => 'clearhelpbutton', 'tabindex' => '0']);
         }
         if ($content === '') {
             return '';
@@ -3294,7 +3334,7 @@ EOD;
             }
             $content = $this->render($link);
         } else if ($item->action instanceof moodle_url) {
-            $attributes = array();
+            $attributes = [];
             if ($title !== '') {
                 $attributes['title'] = $title;
             }
@@ -3302,9 +3342,8 @@ EOD;
                 $attributes['class'] = 'dimmed_text';
             }
             $content = html_writer::link($item->action, $content, $attributes);
-
         } else if (is_string($item->action) || empty($item->action)) {
-            $attributes = array('tabindex'=>'0'); //add tab support to span but still maintain character stream sequence.
+            $attributes = ['tabindex' => '0']; // add tab support to span but still maintain character stream sequence.
             if ($title !== '') {
                 $attributes['title'] = $title;
             }
@@ -3375,7 +3414,7 @@ EOD;
      * and then configuring the custommenu config setting as described.
      *
      * Theme developers: DO NOT OVERRIDE! Please override function
-     * {@link core_renderer::render_custom_menu()} instead.
+     * {@see core_renderer::render_custom_menu()} instead.
      *
      * @param string $custommenuitems - custom menuitems set by theme instead of global theme settings
      * @return string
@@ -3415,7 +3454,7 @@ EOD;
             }
             $this->language = $custommenu->add($currentlang, new moodle_url('#'), $strlang, 10000);
             foreach ($langs as $langtype => $langname) {
-                $this->language->add($langname, new moodle_url($this->page->url, array('lang' => $langtype)), $langname);
+                $this->language->add($langname, new moodle_url($this->page->url, ['lang' => $langtype]), $langname);
             }
         }
 
@@ -3495,11 +3534,11 @@ EOD;
             if ($menunode->get_url() !== null) {
                 $url = $menunode->get_url();
             } else {
-                $url = '#cm_submenu_'.$submenucount;
+                $url = '#cm_submenu_' . $submenucount;
             }
-            $content .= html_writer::link($url, $menunode->get_text(), array('class'=>'yui3-menu-label', 'title'=>$menunode->get_title()));
-            $content .= html_writer::start_tag('div', array('id'=>'cm_submenu_'.$submenucount, 'class'=>'yui3-menu custom_menu_submenu'));
-            $content .= html_writer::start_tag('div', array('class'=>'yui3-menu-content'));
+            $content .= html_writer::link($url, $menunode->get_text(), ['class' => 'yui3-menu-label', 'title' => $menunode->get_title()]);
+            $content .= html_writer::start_tag('div', ['id' => 'cm_submenu_' . $submenucount, 'class' => 'yui3-menu custom_menu_submenu']);
+            $content .= html_writer::start_tag('div', ['class' => 'yui3-menu-content']);
             $content .= html_writer::start_tag('ul');
             foreach ($menunode->get_children() as $menunode) {
                 $content .= $this->render_custom_menu_item($menunode);
@@ -3513,15 +3552,14 @@ EOD;
             // Also, if the node's text matches '####', add a class so we can treat it as a divider.
             $content = '';
             if (preg_match("/^#+$/", $menunode->get_text())) {
-
                 // This is a divider.
-                $content = html_writer::start_tag('li', array('class' => 'yui3-menuitem divider'));
+                $content = html_writer::start_tag('li', ['class' => 'yui3-menuitem divider']);
             } else {
                 $content = html_writer::start_tag(
                     'li',
-                    array(
-                        'class' => 'yui3-menuitem'
-                    )
+                    [
+                        'class' => 'yui3-menuitem',
+                    ]
                 );
                 if ($menunode->get_url() !== null) {
                     $url = $menunode->get_url();
@@ -3531,7 +3569,7 @@ EOD;
                 $content .= html_writer::link(
                     $url,
                     $menunode->get_text(),
-                    array('class' => 'yui3-menuitem-content', 'title' => $menunode->get_title())
+                    ['class' => 'yui3-menuitem-content', 'title' => $menunode->get_title()]
                 );
             }
             $content .= html_writer::end_tag('li');
@@ -3564,10 +3602,10 @@ EOD;
             $linktext = get_string('switchdevicedefault');
             $devicetype = 'default';
         }
-        $linkurl = new moodle_url('/theme/switchdevice.php', array('url' => $this->page->url, 'device' => $devicetype, 'sesskey' => sesskey()));
+        $linkurl = new moodle_url('/theme/switchdevice.php', ['url' => $this->page->url, 'device' => $devicetype, 'sesskey' => sesskey()]);
 
-        $content  = html_writer::start_tag('div', array('id' => 'theme_switch_link'));
-        $content .= html_writer::link($linkurl, $linktext, array('rel' => 'nofollow'));
+        $content  = html_writer::start_tag('div', ['id' => 'theme_switch_link']);
+        $content .= html_writer::link($linkurl, $linktext, ['rel' => 'nofollow']);
         $content .= html_writer::end_tag('div');
 
         return $content;
@@ -3579,7 +3617,7 @@ EOD;
      * This function replaces print_tabs() used before Moodle 2.5 but with slightly different arguments
      *
      * Theme developers: In order to change how tabs are displayed please override functions
-     * {@link core_renderer::render_tabtree()} and/or {@link core_renderer::render_tabobject()}
+     * {@see core_renderer::render_tabtree()} and/or {@see core_renderer::render_tabobject()}
      *
      * @param array $tabs array of tabs, each of them may have it's own ->subtree
      * @param string|null $selected which tab to mark as selected, all parent tabs will
@@ -3609,7 +3647,7 @@ EOD;
     /**
      * Renders tabobject (part of tabtree)
      *
-     * This function is called from {@link core_renderer::render_tabtree()}
+     * This function is called from {@see core_renderer::render_tabtree()}
      * and also it calls itself when printing the $tabobject subtree recursively.
      *
      * Property $tabobject->level indicates the number of row of tabs.
@@ -3625,27 +3663,27 @@ EOD;
             // No name for tabtree root.
         } else if ($tabobject->inactive || $tabobject->activated || ($tabobject->selected && !$tabobject->linkedwhenselected)) {
             // Tab name without a link. The <a> tag is used for styling.
-            $str .= html_writer::tag('a', html_writer::span($tabobject->text), array('class' => 'nolink moodle-has-zindex'));
+            $str .= html_writer::tag('a', html_writer::span($tabobject->text), ['class' => 'nolink moodle-has-zindex']);
         } else {
             // Tab name with a link.
             if (!($tabobject->link instanceof moodle_url)) {
                 // backward compartibility when link was passed as quoted string
                 $str .= "<a href=\"$tabobject->link\" title=\"$tabobject->title\"><span>$tabobject->text</span></a>";
             } else {
-                $str .= html_writer::link($tabobject->link, html_writer::span($tabobject->text), array('title' => $tabobject->title));
+                $str .= html_writer::link($tabobject->link, html_writer::span($tabobject->text), ['title' => $tabobject->title]);
             }
         }
 
         if (empty($tabobject->subtree)) {
             if ($tabobject->selected) {
-                $str .= html_writer::tag('div', '&nbsp;', array('class' => 'tabrow'. ($tabobject->level + 1). ' empty'));
+                $str .= html_writer::tag('div', '&nbsp;', ['class' => 'tabrow' . ($tabobject->level + 1) . ' empty']);
             }
             return $str;
         }
 
         // Print subtree.
         if ($tabobject->level == 0 || $tabobject->selected || $tabobject->activated) {
-            $str .= html_writer::start_tag('ul', array('class' => 'tabrow'. $tabobject->level));
+            $str .= html_writer::start_tag('ul', ['class' => 'tabrow' . $tabobject->level]);
             $cnt = 0;
             foreach ($tabobject->subtree as $tab) {
                 $liclass = '';
@@ -3666,7 +3704,7 @@ EOD;
                 }
 
                 // This will recursively call function render_tabobject() for each item in subtree.
-                $str .= html_writer::tag('li', $this->render($tab), array('class' => trim($liclass)));
+                $str .= html_writer::tag('li', $this->render($tab), ['class' => trim($liclass)]);
                 $cnt++;
             }
             $str .= html_writer::end_tag('ul');
@@ -3685,16 +3723,16 @@ EOD;
      * @param boolean $fakeblocksonly Include fake blocks only.
      * @return string HTML.
      */
-    public function blocks($region, $classes = array(), $tag = 'aside', $fakeblocksonly = false) {
+    public function blocks($region, $classes = [], $tag = 'aside', $fakeblocksonly = false) {
         $displayregion = $this->page->apply_theme_region_manipulations($region);
         $classes = (array)$classes;
         $classes[] = 'block-region';
-        $attributes = array(
-            'id' => 'block-region-'.preg_replace('#[^a-zA-Z0-9_\-]+#', '-', $displayregion),
+        $attributes = [
+            'id' => 'block-region-' . preg_replace('#[^a-zA-Z0-9_\-]+#', '-', $displayregion),
             'class' => join(' ', $classes),
             'data-blockregion' => $displayregion,
-            'data-droptarget' => '1'
-        );
+            'data-droptarget' => '1',
+        ];
         if ($this->page->blocks->region_has_content($displayregion, $this)) {
             $content = html_writer::tag('h2', get_string('blocks'), ['class' => 'sr-only']) .
                 $this->blocks_for_region($displayregion, $fakeblocksonly);
@@ -3733,7 +3771,7 @@ EOD;
      * @param array $additionalclasses Any additional classes to apply.
      * @return string
      */
-    public function body_css_classes(array $additionalclasses = array()) {
+    public function body_css_classes(array $additionalclasses = []) {
         return $this->page->bodyclasses . ' ' . implode(' ', $additionalclasses);
     }
 
@@ -3754,11 +3792,11 @@ EOD;
      * @param string|array $additionalclasses Any additional classes to give the body tag,
      * @return string
      */
-    public function body_attributes($additionalclasses = array()) {
+    public function body_attributes($additionalclasses = []) {
         if (!is_array($additionalclasses)) {
             $additionalclasses = explode(' ', $additionalclasses);
         }
-        return ' id="'. $this->body_id().'" class="'.$this->body_css_classes($additionalclasses).'"';
+        return ' id="' . $this->body_id() . '" class="' . $this->body_css_classes($additionalclasses) . '"';
     }
 
     /**
@@ -3812,9 +3850,11 @@ EOD;
 
         // Do not provide a link to contact site support if it is unavailable to this user. This would be where the site has
         // disabled support, or limited it to authenticated users and the current user is a guest or not logged in.
-        if (!isset($CFG->supportavailability) ||
+        if (
+            !isset($CFG->supportavailability) ||
                 $CFG->supportavailability == CONTACT_SUPPORT_DISABLED ||
-                ($CFG->supportavailability == CONTACT_SUPPORT_AUTHENTICATED && (!isloggedin() || isguestuser()))) {
+                ($CFG->supportavailability == CONTACT_SUPPORT_AUTHENTICATED && (!isloggedin() || isguestuser()))
+        ) {
             return '';
         }
 
@@ -3847,9 +3887,11 @@ EOD;
     public function services_support_link(): string {
         global $CFG;
 
-        if (during_initial_install() ||
+        if (
+            during_initial_install() ||
             (isset($CFG->showservicesandsupportcontent) && $CFG->showservicesandsupportcontent == false) ||
-            !is_siteadmin()) {
+            !is_siteadmin()
+        ) {
             return '';
         }
 
@@ -3945,8 +3987,14 @@ EOD;
         }
 
         // Use $CFG->themerev to prevent browser caching when the file changes.
-        return moodle_url::make_pluginfile_url(context_system::instance()->id, 'core_admin', 'favicon', '64x64/',
-            theme_get_revision(), $logo);
+        return moodle_url::make_pluginfile_url(
+            context_system::instance()->id,
+            'core_admin',
+            'favicon',
+            '64x64/',
+            theme_get_revision(),
+            $logo
+        );
     }
 
     /**
@@ -3967,7 +4015,7 @@ EOD;
      */
     public function render_preferences_group(preferences_group $renderable) {
         $html = '';
-        $html .= html_writer::start_tag('div', array('class' => 'col-sm-4 preferences-group'));
+        $html .= html_writer::start_tag('div', ['class' => 'col-sm-4 preferences-group']);
         $html .= $this->heading($renderable->title, 3);
         $html .= html_writer::start_tag('ul');
         foreach ($renderable->nodes as $node) {
@@ -4003,7 +4051,7 @@ EOD;
                 $user = $headerinfo['user'];
             } else {
                 // Look up the user information if it is not supplied.
-                $user = $DB->get_record('user', array('id' => $context->instanceid));
+                $user = $DB->get_record('user', ['id' => $context->instanceid]);
             }
 
             // If the user context is set, then use that for capability checks.
@@ -4023,20 +4071,20 @@ EOD;
                     $heading = fullname($user);
                 }
 
-                $imagedata = $this->user_picture($user, array('size' => 100));
+                $imagedata = $this->user_picture($user, ['size' => 100]);
 
                 // Check to see if we should be displaying a message button.
                 if (!empty($CFG->messaging) && has_capability('moodle/site:sendmessage', $context)) {
-                    $userbuttons = array(
-                        'messages' => array(
+                    $userbuttons = [
+                        'messages' => [
                             'buttontype' => 'message',
                             'title' => get_string('message', 'message'),
-                            'url' => new moodle_url('/message/index.php', array('id' => $user->id)),
+                            'url' => new moodle_url('/message/index.php', ['id' => $user->id]),
                             'image' => 'message',
                             'linkattributes' => \core_message\helper::messageuser_link_params($user->id),
-                            'page' => $this->page
-                        )
-                    );
+                            'page' => $this->page,
+                        ],
+                    ];
 
                     if ($USER->id != $user->id) {
                         $iscontact = \core_message\api::is_contact($USER->id, $user->id);
@@ -4076,19 +4124,19 @@ EOD;
                             $contacturlaction = 'removecontact';
                             $contactimage = 'removecontact';
                         }
-                        $userbuttons['togglecontact'] = array(
+                        $userbuttons['togglecontact'] = [
                                 'buttontype' => 'togglecontact',
                                 'title' => get_string($contacttitle, 'message'),
-                                'url' => new moodle_url('/message/index.php', array(
-                                        'user1' => $USER->id,
-                                        'user2' => $user->id,
-                                        $contacturlaction => $user->id,
-                                        'sesskey' => sesskey())
-                                ),
+                                'url' => new moodle_url('/message/index.php', [
+                                    'user1' => $USER->id,
+                                    'user2' => $user->id,
+                                    $contacturlaction => $user->id,
+                                    'sesskey' => sesskey(),
+                                ]),
                                 'image' => $contactimage,
                                 'linkattributes' => $linkattributes,
-                                'page' => $this->page
-                            );
+                                'page' => $this->page,
+                            ];
                     }
                 }
             } else {
@@ -4136,8 +4184,10 @@ EOD;
         } else if ($homepage == HOMEPAGE_SITE) {
             $homepagetype = 'site-index';
         }
-        if ($this->page->include_region_main_settings_in_header_actions() &&
-                !$this->page->blocks->is_block_present('settings')) {
+        if (
+            $this->page->include_region_main_settings_in_header_actions() &&
+                !$this->page->blocks->is_block_present('settings')
+        ) {
             // Only include the region main settings if the page has requested it and it doesn't already have
             // the settings block on it. The region main settings are included in the settings block and
             // duplicating the content causes behat failures.
@@ -4180,25 +4230,29 @@ EOD;
         $showusermenu = false;
 
         // We are on the course home page.
-        if (($context->contextlevel == CONTEXT_COURSE) &&
+        if (
+            ($context->contextlevel == CONTEXT_COURSE) &&
                 !empty($currentnode) &&
-                ($currentnode->type == navigation_node::TYPE_COURSE || $currentnode->type == navigation_node::TYPE_SECTION)) {
+                ($currentnode->type == navigation_node::TYPE_COURSE || $currentnode->type == navigation_node::TYPE_SECTION)
+        ) {
             $showcoursemenu = true;
         }
 
         $courseformat = course_get_format($this->page->course);
         // This is a single activity course format, always show the course menu on the activity main page.
-        if ($context->contextlevel == CONTEXT_MODULE &&
-                !$courseformat->has_view_page()) {
-
+        if (
+            $context->contextlevel == CONTEXT_MODULE &&
+                !$courseformat->has_view_page()
+        ) {
             $this->page->navigation->initialise();
             $activenode = $this->page->navigation->find_active_node();
             // If the settings menu has been forced then show the menu.
             if ($this->page->is_settings_menu_forced()) {
                 $showcoursemenu = true;
-            } else if (!empty($activenode) && ($activenode->type == navigation_node::TYPE_ACTIVITY ||
-                            $activenode->type == navigation_node::TYPE_RESOURCE)) {
-
+            } else if (
+                !empty($activenode) && ($activenode->type == navigation_node::TYPE_ACTIVITY ||
+                            $activenode->type == navigation_node::TYPE_RESOURCE)
+            ) {
                 // We only want to show the menu on the first page of the activity. This means
                 // the breadcrumb has no additional nodes.
                 if ($currentnode && ($currentnode->key == $activenode->key && $currentnode->type == $activenode->type)) {
@@ -4208,16 +4262,20 @@ EOD;
         }
 
         // This is the site front page.
-        if ($context->contextlevel == CONTEXT_COURSE &&
+        if (
+            $context->contextlevel == CONTEXT_COURSE &&
                 !empty($currentnode) &&
-                $currentnode->key === 'home') {
+                $currentnode->key === 'home'
+        ) {
             $showfrontpagemenu = true;
         }
 
         // This is the user profile page.
-        if ($context->contextlevel == CONTEXT_USER &&
+        if (
+            $context->contextlevel == CONTEXT_USER &&
                 !empty($currentnode) &&
-                ($currentnode->key === 'myprofile')) {
+                ($currentnode->key === 'myprofile')
+        ) {
             $showusermenu = true;
         }
 
@@ -4230,7 +4288,7 @@ EOD;
                 // We only add a list to the full settings menu if we didn't include every node in the short menu.
                 if ($skipped) {
                     $text = get_string('morenavigationlinks');
-                    $url = new moodle_url('/course/admin.php', array('courseid' => $this->page->course->id));
+                    $url = new moodle_url('/course/admin.php', ['courseid' => $this->page->course->id]);
                     $link = new action_link($url, $text, null, null, new pix_icon('t/edit', $text));
                     $menu->add_secondary_action($link);
                 }
@@ -4244,7 +4302,7 @@ EOD;
                 // We only add a list to the full settings menu if we didn't include every node in the short menu.
                 if ($skipped) {
                     $text = get_string('morenavigationlinks');
-                    $url = new moodle_url('/course/admin.php', array('courseid' => $this->page->course->id));
+                    $url = new moodle_url('/course/admin.php', ['courseid' => $this->page->course->id]);
                     $link = new action_link($url, $text, null, null, new pix_icon('t/edit', $text));
                     $menu->add_secondary_action($link);
                 }
@@ -4271,10 +4329,12 @@ EOD;
      * @param boolean $onlytopleafnodes
      * @return boolean nodesskipped - True if nodes were skipped in building the menu
      */
-    protected function build_action_menu_from_navigation(action_menu $menu,
-            navigation_node $node,
-            $indent = false,
-            $onlytopleafnodes = false) {
+    protected function build_action_menu_from_navigation(
+        action_menu $menu,
+        navigation_node $node,
+        $indent = false,
+        $onlytopleafnodes = false
+    ) {
         $skipped = false;
         // Build an action menu based on the visible nodes from this navigation tree.
         foreach ($node->children as $menuitem) {
@@ -4325,16 +4385,16 @@ EOD;
         $menu = new action_menu();
 
         if ($context->contextlevel == CONTEXT_MODULE) {
-
             $this->page->navigation->initialise();
             $node = $this->page->navigation->find_active_node();
             $buildmenu = false;
             // If the settings menu has been forced then show the menu.
             if ($this->page->is_settings_menu_forced()) {
                 $buildmenu = true;
-            } else if (!empty($node) && ($node->type == navigation_node::TYPE_ACTIVITY ||
-                            $node->type == navigation_node::TYPE_RESOURCE)) {
-
+            } else if (
+                !empty($node) && ($node->type == navigation_node::TYPE_ACTIVITY ||
+                            $node->type == navigation_node::TYPE_RESOURCE)
+            ) {
                 $items = $this->page->navbar->get_items();
                 $navbarnode = end($items);
                 // We only want to show the menu on the first page of the activity. This means
@@ -4351,7 +4411,6 @@ EOD;
                     $this->build_action_menu_from_navigation($menu, $node);
                 }
             }
-
         } else if ($context->contextlevel == CONTEXT_COURSECAT) {
             // For course category context, show category settings menu, if we're on the course category page.
             if ($this->page->pagetype === 'course-index-category') {
@@ -4361,7 +4420,6 @@ EOD;
                     $this->build_action_menu_from_navigation($menu, $node);
                 }
             }
-
         } else {
             $items = $this->page->navbar->get_items();
             $navbarnode = end($items);
@@ -4372,7 +4430,6 @@ EOD;
                     // Build an action menu based on the visible nodes from this navigation tree.
                     $this->build_action_menu_from_navigation($menu, $node);
                 }
-
             }
         }
         return $this->render($menu);
@@ -4391,8 +4448,14 @@ EOD;
      * @param bool $accesshidelabel if true, the label should have class="accesshide" added.
      * @return string
      */
-    public function tag_list($tags, $label = null, $classes = '', $limit = 10,
-            $pagecontext = null, $accesshidelabel = false) {
+    public function tag_list(
+        $tags,
+        $label = null,
+        $classes = '',
+        $limit = 10,
+        $pagecontext = null,
+        $accesshidelabel = false
+    ) {
         $list = new taglist($tags, $label, $classes, $limit, $pagecontext, $accesshidelabel);
         return $this->render_from_template('core_tag/taglist', $list->export_for_template($this));
     }
@@ -4448,7 +4511,7 @@ EOD;
         $chartdata = json_encode($chart);
         return $this->render_from_template('core/chart', (object) [
             'chartdata' => $chartdata,
-            'withtable' => $withtable
+            'withtable' => $withtable,
         ]);
     }
 
@@ -4469,8 +4532,11 @@ EOD;
             $url = $url->out(false);
         }
         $context->logourl = $url;
-        $context->sitename = format_string($SITE->fullname, true,
-                ['context' => context_course::instance(SITEID), "escape" => false]);
+        $context->sitename = format_string(
+            $SITE->fullname,
+            true,
+            ['context' => context_course::instance(SITEID), "escape" => false]
+        );
 
         return $this->render_from_template('core/loginform', $context);
     }
@@ -4529,15 +4595,15 @@ EOD;
                     $elementcontext['wrapperid'] = 'fitem_' . $elementcontext['id'];
                 }
 
-                $context = array(
+                $context = [
                     'element' => $elementcontext,
                     'label' => $label,
                     'text' => $text,
                     'required' => $required,
                     'advanced' => $advanced,
                     'helpbutton' => $helpbutton,
-                    'error' => $error
-                );
+                    'error' => $error,
+                ];
                 return $this->render_from_template($templatename, $context);
             }
         } catch (\Exception $e) {
@@ -4561,8 +4627,11 @@ EOD;
             $url = $url->out(false);
         }
         $context['logourl'] = $url;
-        $context['sitename'] = format_string($SITE->fullname, true,
-                ['context' => context_course::instance(SITEID), "escape" => false]);
+        $context['sitename'] = format_string(
+            $SITE->fullname,
+            true,
+            ['context' => context_course::instance(SITEID), "escape" => false]
+        );
 
         return $this->render_from_template('core/signup_form_layout', $context);
     }
@@ -4671,7 +4740,8 @@ EOD;
         if (count($regions) == 0) {
             return '';
         }
-        if (isset($this->page->theme->addblockposition) &&
+        if (
+            isset($this->page->theme->addblockposition) &&
                 $this->page->user_is_editing() &&
                 $this->page->user_can_edit_blocks() &&
                 $this->page->pagelayout !== 'mycourses'
@@ -4681,7 +4751,8 @@ EOD;
                 $params['bui_blockregion'] = $region;
             }
             $url = new moodle_url($this->page->url, $params);
-            $addblockbutton = $this->render_from_template('core/add_block_button',
+            $addblockbutton = $this->render_from_template(
+                'core/add_block_button',
                 [
                     'link' => $url->out(false),
                     'escapedlink' => "?{$url->get_query_string(false)}",
@@ -4730,8 +4801,10 @@ EOD;
     public function select_element_for_append(string $selector = '#region-main [role=main]', string $element = 'div') {
 
         if (!CLI_SCRIPT && !NO_OUTPUT_BUFFERING) {
-            throw new coding_exception('select_element_for_append used in a non-CLI script without setting NO_OUTPUT_BUFFERING.',
-                DEBUG_DEVELOPER);
+            throw new coding_exception(
+                'select_element_for_append used in a non-CLI script without setting NO_OUTPUT_BUFFERING.',
+                DEBUG_DEVELOPER
+            );
         }
 
         // We are already streaming into this element so don't change anything.
@@ -4786,8 +4859,10 @@ EOD;
     public function select_element_for_replace(string $selector, string $html, bool $outer = false) {
 
         if (!CLI_SCRIPT && !NO_OUTPUT_BUFFERING) {
-            throw new coding_exception('select_element_for_replace used in a non-CLI script without setting NO_OUTPUT_BUFFERING.',
-                DEBUG_DEVELOPER);
+            throw new coding_exception(
+                'select_element_for_replace used in a non-CLI script without setting NO_OUTPUT_BUFFERING.',
+                DEBUG_DEVELOPER
+            );
         }
 
         // Escape html for use inside a javascript string.
diff --git a/lib/classes/output/core_renderer_ajax.php b/lib/classes/output/core_renderer_ajax.php
index a70a42b2ed1..41c9786c454 100644
--- a/lib/classes/output/core_renderer_ajax.php
+++ b/lib/classes/output/core_renderer_ajax.php
@@ -40,21 +40,23 @@ class core_renderer_ajax extends core_renderer {
      * @param string $moreinfourl URL where more info can be found about the error
      * @param string $link Link for the Continue button
      * @param array $backtrace The execution backtrace
-     * @param string $debuginfo Debugging information
+     * @param null|string $debuginfo Debugging information
+     * @param string $errorcode
      * @return string A template fragment for a fatal error
      */
     public function fatal_error($message, $moreinfourl, $link, $backtrace, $debuginfo = null, $errorcode = "") {
         global $CFG;
 
-        $this->page->set_context(null); // ugly hack - make sure page context is set to something, we do not want bogus warnings here
+        // Ugly hack - make sure page context is set to something, we do not want bogus warnings here.
+        $this->page->set_context(null);
 
         $e = new stdClass();
         $e->error      = $message;
         $e->errorcode  = $errorcode;
-        $e->stacktrace = NULL;
-        $e->debuginfo  = NULL;
-        $e->reproductionlink = NULL;
-        if (!empty($CFG->debug) and $CFG->debug >= DEBUG_DEVELOPER) {
+        $e->stacktrace = null;
+        $e->debuginfo  = null;
+        $e->reproductionlink = null;
+        if (!empty($CFG->debug) && $CFG->debug >= DEBUG_DEVELOPER) {
             $link = (string) $link;
             if ($link) {
                 $e->reproductionlink = $link;
@@ -99,7 +101,8 @@ class core_renderer_ajax extends core_renderer {
         $delay,
         $debugdisableredirect,
         $messagetype = notification::NOTIFY_INFO,
-    ) {}
+    ) {
+    }
 
     /**
      * Prepares the start of an AJAX output.
@@ -118,7 +121,7 @@ class core_renderer_ajax extends core_renderer {
             @header('Content-type: application/json; charset=utf-8');
         }
 
-        // Headers to make it not cacheable and json
+        // Headers to make it not cacheable and json.
         @header('Cache-Control: no-store, no-cache, must-revalidate');
         @header('Cache-Control: post-check=0, pre-check=0', false);
         @header('Pragma: no-cache');
@@ -131,7 +134,8 @@ class core_renderer_ajax extends core_renderer {
      * There is no footer for an AJAX request, however we must override the
      * footer method to prevent the default footer.
      */
-    public function footer() {}
+    public function footer() {
+    }
 
     /**
      * No need for headers in an AJAX request... this should never happen.
@@ -140,7 +144,8 @@ class core_renderer_ajax extends core_renderer {
      * @param string $classes
      * @param string $id
      */
-    public function heading($text, $level = 2, $classes = 'main', $id = null) {}
+    public function heading($text, $level = 2, $classes = 'main', $id = null) {
+    }
 }
 
 // Alias this class to the old name.
diff --git a/lib/classes/output/core_renderer_cli.php b/lib/classes/output/core_renderer_cli.php
index 1de38c598a1..d277966bd2a 100644
--- a/lib/classes/output/core_renderer_cli.php
+++ b/lib/classes/output/core_renderer_cli.php
@@ -33,7 +33,6 @@ use core\check\result as check_result;
 class core_renderer_cli extends core_renderer {
     /**
      * @var array $progressmaximums stores the largest percentage for a progress bar.
-     * @return string ascii fragment
      */
     private $progressmaximums = [];
 
@@ -59,10 +58,10 @@ class core_renderer_cli extends core_renderer {
         $status = $result->get_status();
 
         $labels = [
-            check_result::NA        => '      ' . cli_ansi_format('<colour:darkGray>' ) . ' NA ',
+            check_result::NA        => '      ' . cli_ansi_format('<colour:darkGray>') . ' NA ',
             check_result::OK        => '      ' . cli_ansi_format('<colour:green>') . ' OK ',
-            check_result::INFO      => '    '   . cli_ansi_format('<colour:blue>' ) . ' INFO ',
-            check_result::UNKNOWN   => ' '      . cli_ansi_format('<colour:darkGray>' ) . ' UNKNOWN ',
+            check_result::INFO      => '    '   . cli_ansi_format('<colour:blue>') . ' INFO ',
+            check_result::UNKNOWN   => ' '      . cli_ansi_format('<colour:darkGray>') . ' UNKNOWN ',
             check_result::WARNING   => ' '      . cli_ansi_format('<colour:black><bgcolour:yellow>') . ' WARNING ',
             check_result::ERROR     => '   '    . cli_ansi_format('<bgcolour:red>') . ' ERROR ',
             check_result::CRITICAL  => ''       . cli_ansi_format('<bgcolour:red>') . ' CRITICAL ',
@@ -96,7 +95,7 @@ class core_renderer_cli extends core_renderer {
         $ascii = "\n";
 
         if (stream_isatty(STDOUT)) {
-            require_once($CFG->libdir.'/clilib.php');
+            require_once($CFG->libdir . '/clilib.php');
 
             $ascii .= "[" . str_repeat(' ', $size) . "] 0% \n";
             return cli_ansi_format($ascii);
@@ -199,7 +198,8 @@ class core_renderer_cli extends core_renderer {
      * @param string $moreinfourl URL where more info can be found about the error
      * @param string $link Link for the Continue button
      * @param array $backtrace The execution backtrace
-     * @param string $debuginfo Debugging information
+     * @param null|string $debuginfo Debugging information
+     * @param string $errorcode
      * @return string A template fragment for a fatal error
      */
     public function fatal_error($message, $moreinfourl, $link, $backtrace, $debuginfo = null, $errorcode = "") {
diff --git a/lib/classes/output/core_renderer_maintenance.php b/lib/classes/output/core_renderer_maintenance.php
index 1aee2863dc0..50b4153cb95 100644
--- a/lib/classes/output/core_renderer_maintenance.php
+++ b/lib/classes/output/core_renderer_maintenance.php
@@ -70,7 +70,7 @@ class core_renderer_maintenance extends core_renderer {
      * @param boolean $fakeblocksonly
      * @return string
      */
-    public function blocks($region, $classes = array(), $tag = 'aside', $fakeblocksonly = false) {
+    public function blocks($region, $classes = [], $tag = 'aside', $fakeblocksonly = false) {
         return '';
     }
 
@@ -158,11 +158,19 @@ class core_renderer_maintenance extends core_renderer {
         if ($continue instanceof single_button) {
             $continue->type = single_button::BUTTON_PRIMARY;
         } else if (is_string($continue)) {
-            $continue = new single_button(new moodle_url($continue), get_string('continue'), 'post',
-                $displayoptions['type'] ?? single_button::BUTTON_PRIMARY);
+            $continue = new single_button(
+                new moodle_url($continue),
+                get_string('continue'),
+                'post',
+                $displayoptions['type'] ?? single_button::BUTTON_PRIMARY
+            );
         } else if ($continue instanceof moodle_url) {
-            $continue = new single_button($continue, get_string('continue'), 'post',
-                $displayoptions['type'] ?? single_button::BUTTON_PRIMARY);
+            $continue = new single_button(
+                $continue,
+                get_string('continue'),
+                'post',
+                $displayoptions['type'] ?? single_button::BUTTON_PRIMARY
+            );
         } else {
             throw new coding_exception('The continue param to $OUTPUT->confirm() must be either a URL' .
                                        ' (string/moodle_url) or a single_button instance.');
@@ -228,10 +236,10 @@ class core_renderer_maintenance extends core_renderer {
      * Does nothing. The maintenance renderer cannot produce user pictures.
      *
      * @param stdClass $user
-     * @param array $options
+     * @param null|array $options
      * @return string
      */
-    public function user_picture(stdClass $user, array $options = null) {
+    public function user_picture(stdClass $user, ?array $options = null) {
         return '';
     }
 }
diff --git a/lib/classes/output/custom_menu.php b/lib/classes/output/custom_menu.php
index 67ab20ee60d..5357df2b78d 100644
--- a/lib/classes/output/custom_menu.php
+++ b/lib/classes/output/custom_menu.php
@@ -44,7 +44,7 @@ class custom_menu extends custom_menu_item {
     /**
      * Creates the custom menu
      *
-     * @param string $definition the menu items definition in syntax required by {@link convert_text_to_menu_nodes()}
+     * @param string $definition the menu items definition in syntax required by {@see convert_text_to_menu_nodes()}
      * @param string $currentlanguage the current language code, null disables multilang support
      */
     public function __construct($definition = '', $currentlanguage = null) {
@@ -62,7 +62,7 @@ class custom_menu extends custom_menu_item {
      * @param array $children
      */
     public function override_children(array $children) {
-        $this->children = array();
+        $this->children = [];
         foreach ($children as $child) {
             if ($child instanceof custom_menu_item) {
                 $this->children[] = $child;
@@ -100,7 +100,7 @@ class custom_menu extends custom_menu_item {
         $root = new custom_menu();
         $lastitem = $root;
         $lastdepth = 0;
-        $hiddenitems = array();
+        $hiddenitems = [];
         $lines = explode("\n", $text);
         foreach ($lines as $linenumber => $line) {
             $line = trim($line);
diff --git a/lib/classes/output/custom_menu_item.php b/lib/classes/output/custom_menu_item.php
index 314cfeebeb8..c1e1a389530 100644
--- a/lib/classes/output/custom_menu_item.php
+++ b/lib/classes/output/custom_menu_item.php
@@ -33,17 +33,11 @@ use stdClass;
  * @category output
  */
 class custom_menu_item implements renderable, templatable {
-
     /**
      * @var string The text to show for the item
      */
     protected $text;
 
-    /**
-     * @var moodle_url The link to give the icon if it has no children
-     */
-    protected $url;
-
     /**
      * @var string A title to apply to the item. By default the text
      */
@@ -55,60 +49,66 @@ class custom_menu_item implements renderable, templatable {
      */
     protected $sort;
 
-    /**
-     * @var custom_menu_item A reference to the parent for this item or NULL if
-     * it is a top level item
-     */
-    protected $parent;
-
     /**
      * @var array A array in which to store children this item has.
      */
-    protected $children = array();
+    protected $children = [];
 
     /**
      * @var int A reference to the sort var of the last child that was added
      */
     protected $lastsort = 0;
 
-    /** @var array Array of other HTML attributes for the custom menu item. */
-    protected $attributes = [];
-
     /**
      * Constructs the new custom menu item
      *
      * @param string $text
-     * @param moodle_url $url A moodle url to apply as the link for this item [Optional]
+     * @param null|moodle_url $url A moodle url to apply as the link for this item [Optional]
      * @param string $title A title to apply to this item [Optional]
      * @param int $sort A sort or to use if we need to sort differently [Optional]
-     * @param custom_menu_item $parent A reference to the parent custom_menu_item this child
+     * @param null|custom_menu_item $parent A reference to the parent custom_menu_item this child
      *        belongs to, only if the child has a parent. [Optional]
      * @param array $attributes Array of other HTML attributes for the custom menu item.
      */
-    public function __construct($text, moodle_url $url = null, $title = null, $sort = null, custom_menu_item $parent = null,
-        array $attributes = []) {
+    public function __construct(
+        $text,
+        /** @var moodle_url The link to give the icon if it has no children */
+        protected ?moodle_url $url = null,
+        $title = null,
+        $sort = null,
+        /**
+         * @var custom_menu_item A reference to the parent for this item or NULL if
+         * it is a top level item
+         */
+        protected ?custom_menu_item $parent = null,
+        /** @var array Array of other HTML attributes for the custom menu item. */
+        protected array $attributes = [],
+    ) {
 
         // Use class setter method for text to ensure it's always a string type.
         $this->set_text($text);
 
-        $this->url = $url;
         $this->title = $title;
         $this->sort = (int)$sort;
-        $this->parent = $parent;
-        $this->attributes = $attributes;
     }
 
     /**
      * Adds a custom menu item as a child of this node given its properties.
      *
      * @param string $text
-     * @param moodle_url $url
+     * @param null|moodle_url $url
      * @param string $title
      * @param int $sort
      * @param array $attributes Array of other HTML attributes for the custom menu item.
      * @return custom_menu_item
      */
-    public function add($text, moodle_url $url = null, $title = null, $sort = null, $attributes = []) {
+    public function add(
+        $text,
+        ?moodle_url $url = null,
+        $title = null,
+        $sort = null,
+        $attributes = [],
+    ) {
         $key = count($this->children);
         if (empty($sort)) {
             $sort = $this->lastsort + 1;
@@ -195,7 +195,7 @@ class custom_menu_item implements renderable, templatable {
      * Sorts the children this item has
      */
     public function sort() {
-        usort($this->children, array('custom_menu','sort_custom_menu_items'));
+        usort($this->children, ['custom_menu', 'sort_custom_menu_items']);
     }
 
     /**
@@ -252,7 +252,7 @@ class custom_menu_item implements renderable, templatable {
         if (!empty($this->attributes)) {
             $context->attributes = $this->attributes;
         }
-        $context->children = array();
+        $context->children = [];
         if (preg_match("/^#+$/", $this->text)) {
             $context->divider = true;
         }
diff --git a/lib/classes/output/datafilter.php b/lib/classes/output/datafilter.php
index 04973ef3d93..e8cef3acf2d 100644
--- a/lib/classes/output/datafilter.php
+++ b/lib/classes/output/datafilter.php
@@ -28,7 +28,6 @@ use stdClass;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 abstract class datafilter implements renderable, templatable {
-
     /** @var int None of the following match */
     public const JOINTYPE_NONE = 0;
 
@@ -108,7 +107,7 @@ abstract class datafilter implements renderable, templatable {
             'values' => $values,
             'filteroptions' => $filteroptions,
             'required' => $required,
-            'joinlist' => json_encode($joinlist)
+            'joinlist' => json_encode($joinlist),
         ];
     }
 }
diff --git a/lib/classes/output/dynamic_tabs.php b/lib/classes/output/dynamic_tabs.php
index 1dbb26df2e6..c739934b0d1 100644
--- a/lib/classes/output/dynamic_tabs.php
+++ b/lib/classes/output/dynamic_tabs.php
@@ -28,7 +28,6 @@ use core\output\dynamic_tabs\base;
  * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class dynamic_tabs implements templatable {
-
     /** @var base[]  */
     protected $tabs = [];
 
@@ -60,7 +59,7 @@ class dynamic_tabs implements templatable {
      */
     public function export_for_template(renderer_base $output): array {
         $data = [
-            'tabs' => []
+            'tabs' => [],
         ];
 
         foreach ($this->tabs as $tab) {
diff --git a/lib/classes/output/dynamic_tabs/base.php b/lib/classes/output/dynamic_tabs/base.php
index 477b73587ec..213148be34b 100644
--- a/lib/classes/output/dynamic_tabs/base.php
+++ b/lib/classes/output/dynamic_tabs/base.php
@@ -29,7 +29,6 @@ use core\output\templatable;
  * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 abstract class base implements templatable {
-
     /** @var array */
     protected $data;
 
diff --git a/lib/classes/output/external.php b/lib/classes/output/external.php
index b9c24e049c3..181faf9d6ca 100644
--- a/lib/classes/output/external.php
+++ b/lib/classes/output/external.php
@@ -39,13 +39,12 @@ class external extends external_api {
      * @return external_function_parameters
      */
     public static function load_template_parameters() {
-        return new external_function_parameters(
-                array('component' => new external_value(PARAM_COMPONENT, 'component containing the template'),
-                      'template' => new external_value(PARAM_SAFEPATH, 'name of the template'),
-                      'themename' => new external_value(PARAM_ALPHANUMEXT, 'The current theme.'),
-                      'includecomments' => new external_value(PARAM_BOOL, 'Include comments or not', VALUE_DEFAULT, false)
-                         )
-            );
+        return new external_function_parameters([
+            'component' => new external_value(PARAM_COMPONENT, 'component containing the template'),
+            'template' => new external_value(PARAM_SAFEPATH, 'name of the template'),
+            'themename' => new external_value(PARAM_ALPHANUMEXT, 'The current theme.'),
+            'includecomments' => new external_value(PARAM_BOOL, 'Include comments or not', VALUE_DEFAULT, false),
+        ]);
     }
 
     /**
@@ -60,11 +59,15 @@ class external extends external_api {
         global $DB, $CFG, $PAGE;
 
         $PAGE->set_context(context_system::instance());
-        $params = self::validate_parameters(self::load_template_parameters(),
-                                            array('component' => $component,
-                                                  'template' => $template,
-                                                  'themename' => $themename,
-                                                  'includecomments' => $includecomments));
+        $params = self::validate_parameters(
+            self::load_template_parameters(),
+            [
+                'component' => $component,
+                'template' => $template,
+                'themename' => $themename,
+                'includecomments' => $includecomments,
+            ],
+        );
 
         $loader = new mustache_template_source_loader();
         // Will throw exceptions if the template does not exist.
@@ -72,7 +75,7 @@ class external extends external_api {
             $params['component'],
             $params['template'],
             $params['themename'],
-            $params['includecomments']
+            $params['includecomments'],
         );
     }
 
@@ -108,7 +111,7 @@ class external extends external_api {
      * @param string $themename The name of the current theme.
      * @param bool $includecomments Whether to strip comments from the template source.
      * @param string $lang moodle translation language, null means use current.
-     * @return string the template
+     * @return array the template
      */
     public static function load_template_with_dependencies(
         string $component,
@@ -126,7 +129,7 @@ class external extends external_api {
                 'template' => $template,
                 'themename' => $themename,
                 'includecomments' => $includecomments,
-                'lang' => $lang
+                'lang' => $lang,
             ]
         );
 
@@ -141,14 +144,14 @@ class external extends external_api {
             [],
             $params['lang']
         );
-        $formatdependencies = function($dependency) {
+        $formatdependencies = function ($dependency) {
             $results = [];
             foreach ($dependency as $dependencycomponent => $dependencyvalues) {
                 foreach ($dependencyvalues as $dependencyname => $dependencyvalue) {
                     array_push($results, [
                         'component' => $dependencycomponent,
                         'name' => $dependencyname,
-                        'value' => $dependencyvalue
+                        'value' => $dependencyvalue,
                     ]);
                 }
             }
@@ -159,7 +162,7 @@ class external extends external_api {
         // by external functions (because they don't support dynamic keys).
         return [
             'templates' => $formatdependencies($dependencies['templates']),
-            'strings' => $formatdependencies($dependencies['strings'])
+            'strings' => $formatdependencies($dependencies['strings']),
         ];
     }
 
@@ -172,12 +175,12 @@ class external extends external_api {
         $resourcestructure = new external_single_structure([
             'component' => new external_value(PARAM_COMPONENT, 'component containing the resource'),
             'name' => new external_value(PARAM_TEXT, 'name of the resource'),
-            'value' => new external_value(PARAM_RAW, 'resource value')
+            'value' => new external_value(PARAM_RAW, 'resource value'),
         ]);
 
         return new external_single_structure([
             'templates' => new external_multiple_structure($resourcestructure),
-            'strings' => new external_multiple_structure($resourcestructure)
+            'strings' => new external_multiple_structure($resourcestructure),
         ]);
     }
 
diff --git a/lib/classes/output/file_picker.php b/lib/classes/output/file_picker.php
index 783e29fe71c..2a3bdd3e0d3 100644
--- a/lib/classes/output/file_picker.php
+++ b/lib/classes/output/file_picker.php
@@ -52,18 +52,18 @@ class file_picker implements renderable {
      */
     public function __construct(stdClass $options) {
         global $CFG, $USER, $PAGE;
-        require_once($CFG->dirroot. '/repository/lib.php');
-        $defaults = array(
-            'accepted_types'=>'*',
-            'return_types'=>FILE_INTERNAL,
+        require_once($CFG->dirroot . '/repository/lib.php');
+        $defaults = [
+            'accepted_types' => '*',
+            'return_types' => FILE_INTERNAL,
             'env' => 'filepicker',
             'client_id' => uniqid(),
             'itemid' => 0,
-            'maxbytes'=>-1,
-            'maxfiles'=>1,
-            'buttonname'=>false
-        );
-        foreach ($defaults as $key=>$value) {
+            'maxbytes' => -1,
+            'maxfiles' => 1,
+            'buttonname' => false,
+        ];
+        foreach ($defaults as $key => $value) {
             if (empty($options->$key)) {
                 $options->$key = $value;
             }
@@ -81,15 +81,19 @@ class file_picker implements renderable {
                 $file = $fs->get_file($usercontext->id, 'user', 'draft', $options->itemid, $options->filepath, $options->filename);
             }
             if (!empty($file)) {
-                $options->currentfile = html_writer::link(moodle_url::make_draftfile_url($file->get_itemid(), $file->get_filepath(), $file->get_filename()), $file->get_filename());
+                $options->currentfile = html_writer::link(moodle_url::make_draftfile_url(
+                    $file->get_itemid(),
+                    $file->get_filepath(),
+                    $file->get_filename(),
+                ), $file->get_filename());
             }
         }
 
-        // initilise options, getting files in root path
+        // Initialise options, getting files in root path.
         $this->options = initialise_filepicker($options);
 
-        // copying other options
-        foreach ($options as $name=>$value) {
+        // Copying other options.
+        foreach ($options as $name => $value) {
             if (!isset($this->options->$name)) {
                 $this->options->$name = $value;
             }
diff --git a/lib/classes/output/help_icon.php b/lib/classes/output/help_icon.php
index 6c36b1cf918..4fd2beec17f 100644
--- a/lib/classes/output/help_icon.php
+++ b/lib/classes/output/help_icon.php
@@ -75,7 +75,7 @@ class help_icon implements renderable, templatable {
         if (!$sm->string_exists($this->identifier, $this->component)) {
             debugging("Help title string does not exist: [$this->identifier, $this->component]");
         }
-        if (!$sm->string_exists($this->identifier.'_help', $this->component)) {
+        if (!$sm->string_exists($this->identifier . '_help', $this->component)) {
             debugging("Help contents string does not exist: [{$this->identifier}_help, $this->component]");
         }
     }
@@ -107,7 +107,7 @@ class help_icon implements renderable, templatable {
         $options = [
             'component' => $this->component,
             'identifier' => $this->identifier,
-            'lang' => current_language()
+            'lang' => current_language(),
         ];
 
         // Debugging feature lets you display string identifier and component.
diff --git a/lib/classes/output/html_writer.php b/lib/classes/output/html_writer.php
index 3f00022d876..f9331da6038 100644
--- a/lib/classes/output/html_writer.php
+++ b/lib/classes/output/html_writer.php
@@ -38,10 +38,10 @@ class html_writer {
      *
      * @param string $tagname The name of tag ('a', 'img', 'span' etc.)
      * @param string $contents What goes between the opening and closing tags
-     * @param array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
+     * @param null|array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
      * @return string HTML fragment
      */
-    public static function tag($tagname, $contents, array $attributes = null) {
+    public static function tag($tagname, $contents, ?array $attributes = null) {
         return self::start_tag($tagname, $attributes) . $contents . self::end_tag($tagname);
     }
 
@@ -49,10 +49,10 @@ class html_writer {
      * Outputs an opening tag with attributes
      *
      * @param string $tagname The name of tag ('a', 'img', 'span' etc.)
-     * @param array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
+     * @param null|array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
      * @return string HTML fragment
      */
-    public static function start_tag($tagname, array $attributes = null) {
+    public static function start_tag($tagname, ?array $attributes = null) {
         return '<' . $tagname . self::attributes($attributes) . '>';
     }
 
@@ -70,10 +70,10 @@ class html_writer {
      * Outputs an empty tag with attributes
      *
      * @param string $tagname The name of tag ('input', 'img', 'br' etc.)
-     * @param array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
+     * @param null|array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
      * @return string HTML fragment
      */
-    public static function empty_tag($tagname, array $attributes = null) {
+    public static function empty_tag($tagname, ?array $attributes = null) {
         return '<' . $tagname . self::attributes($attributes) . ' />';
     }
 
@@ -82,10 +82,10 @@ class html_writer {
      *
      * @param string $tagname The name of tag ('a', 'img', 'span' etc.)
      * @param string $contents What goes between the opening and closing tags
-     * @param array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
+     * @param null|array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
      * @return string HTML fragment
      */
-    public static function nonempty_tag($tagname, $contents, array $attributes = null) {
+    public static function nonempty_tag($tagname, $contents, ?array $attributes = null) {
         if ($contents === '' || is_null($contents)) {
             return '';
         }
@@ -96,7 +96,7 @@ class html_writer {
      * Outputs a HTML attribute and value
      *
      * @param string $name The name of the attribute ('src', 'href', 'class' etc.)
-     * @param string $value The value of the attribute. The value will be escaped with {@link s()}
+     * @param string $value The value of the attribute. The value will be escaped with {@see s()}
      * @return string HTML fragment
      */
     public static function attribute($name, $value) {
@@ -104,23 +104,23 @@ class html_writer {
             return ' ' . $name . '="' . $value->out() . '"';
         }
 
-        // special case, we do not want these in output
+        // Special case, we do not want these in output.
         if ($value === null) {
             return '';
         }
 
-        // no sloppy trimming here!
+        // No sloppy trimming here!
         return ' ' . $name . '="' . s($value) . '"';
     }
 
     /**
      * Outputs a list of HTML attributes and values
      *
-     * @param array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
-     *       The values will be escaped with {@link s()}
+     * @param null|array $attributes The tag attributes (array('src' => $url, 'class' => 'class1') etc.)
+     *       The values will be escaped with {@see s()}
      * @return string HTML fragment
      */
-    public static function attributes(array $attributes = null) {
+    public static function attributes(?array $attributes = null) {
         $attributes = (array)$attributes;
         $output = '';
         foreach ($attributes as $name => $value) {
@@ -134,10 +134,10 @@ class html_writer {
      *
      * @param string $src The source of image
      * @param string $alt The alternate text for image
-     * @param array $attributes The tag attributes (array('height' => $max_height, 'class' => 'class1') etc.)
+     * @param null|array $attributes The tag attributes (array('height' => $max_height, 'class' => 'class1') etc.)
      * @return string HTML fragment
      */
-    public static function img($src, $alt, array $attributes = null) {
+    public static function img($src, $alt, ?array $attributes = null) {
         $attributes = (array)$attributes;
         $attributes['src'] = $src;
         // In case a null alt text is provided, set it to an empty string.
@@ -161,7 +161,7 @@ class html_writer {
      * @param string $base A string fragment that will be included in the random ID.
      * @return string A unique ID
      */
-    public static function random_id($base='random') {
+    public static function random_id($base = 'random') {
         static $counter = 0;
         static $uniq;
 
@@ -170,7 +170,7 @@ class html_writer {
         }
 
         $counter++;
-        return $base.$uniq.$counter;
+        return $base . $uniq . $counter;
     }
 
     /**
@@ -178,10 +178,10 @@ class html_writer {
      *
      * @param string|moodle_url $url The URL
      * @param string $text The text
-     * @param array $attributes HTML attributes
+     * @param null|array $attributes HTML attributes
      * @return string HTML fragment
      */
-    public static function link($url, $text, array $attributes = null) {
+    public static function link($url, $text, ?array $attributes = null) {
         $attributes = (array)$attributes;
         $attributes['href']  = $url;
         return self::tag('a', $text, $attributes);
@@ -194,16 +194,22 @@ class html_writer {
      * @param string $value The value of the checkbox
      * @param bool $checked Whether the checkbox is checked
      * @param string $label The label for the checkbox
-     * @param array $attributes Any attributes to apply to the checkbox
-     * @param array $labelattributes Any attributes to apply to the label, if present
+     * @param null|array $attributes Any attributes to apply to the checkbox
+     * @param null|array $labelattributes Any attributes to apply to the label, if present
      * @return string html fragment
      */
-    public static function checkbox($name, $value, $checked = true, $label = '',
-        array $attributes = null, array $labelattributes = null) {
+    public static function checkbox(
+        $name,
+        $value,
+        $checked = true,
+        $label = '',
+        ?array $attributes = null,
+        ?array $labelattributes = null,
+    ) {
         $attributes = (array) $attributes;
         $output = '';
 
-        if ($label !== '' and !is_null($label)) {
+        if ($label !== '' && !is_null($label)) {
             if (empty($attributes['id'])) {
                 $attributes['id'] = self::random_id('checkbox_');
             }
@@ -215,7 +221,7 @@ class html_writer {
 
         $output .= self::empty_tag('input', $attributes);
 
-        if ($label !== '' and !is_null($label)) {
+        if ($label !== '' && !is_null($label)) {
             $labelattributes = (array) $labelattributes;
             $labelattributes['for'] = $attributes['id'];
             $output .= self::tag('label', $label, $labelattributes);
@@ -229,11 +235,11 @@ class html_writer {
      *
      * @param string $name name of select element
      * @param bool $selected
-     * @param array $attributes - html select element attributes
+     * @param null|array $attributes - html select element attributes
      * @return string HTML fragment
      */
-    public static function select_yes_no($name, $selected=true, array $attributes = null) {
-        $options = array('1'=>get_string('yes'), '0'=>get_string('no'));
+    public static function select_yes_no($name, $selected = true, ?array $attributes = null) {
+        $options = ['1' => get_string('yes'), '0' => get_string('no')];
         return self::select($options, $name, $selected, null, $attributes);
     }
 
@@ -250,41 +256,46 @@ class html_writer {
      * @param string $name name of select element
      * @param string|array $selected value or array of values depending on multiple attribute
      * @param array|bool|null $nothing add nothing selected option, or false of not added
-     * @param array $attributes html select element attributes
+     * @param null|array $attributes html select element attributes
      * @return string HTML fragment
      */
-    public static function select(array $options, $name, $selected = '', $nothing = array('' => 'choosedots'), array $attributes = null) {
+    public static function select(
+        array $options,
+        $name,
+        $selected = '',
+        $nothing = ['' => 'choosedots'],
+        ?array $attributes = null,
+    ) {
         $attributes = (array)$attributes;
         if (is_array($nothing)) {
-            foreach ($nothing as $k=>$v) {
-                if ($v === 'choose' or $v === 'choosedots') {
+            foreach ($nothing as $k => $v) {
+                if ($v === 'choose' || $v === 'choosedots') {
                     $nothing[$k] = get_string('choosedots');
                 }
             }
-            $options = $nothing + $options; // keep keys, do not override
-
-        } else if (is_string($nothing) and $nothing !== '') {
-            // BC
-            $options = array(''=>$nothing) + $options;
+            $options = $nothing + $options; // Keep keys, do not override.
+        } else if (is_string($nothing) && $nothing !== '') {
+            // BC.
+            $options = ['' => $nothing] + $options;
         }
 
-        // we may accept more values if multiple attribute specified
+        // We may accept more values if multiple attribute specified.
         $selected = (array)$selected;
-        foreach ($selected as $k=>$v) {
+        foreach ($selected as $k => $v) {
             $selected[$k] = (string)$v;
         }
 
         if (!isset($attributes['id'])) {
-            $id = 'menu'.$name;
-            // name may contaion [], which would make an invalid id. e.g. numeric question type editing form, assignment quickgrading
+            $id = 'menu' . $name;
+            // Name may contain [], which would make an invalid id. e.g. numeric question type editing form, assignment quickgrading.
             $id = str_replace('[', '', $id);
             $id = str_replace(']', '', $id);
             $attributes['id'] = $id;
         }
 
         if (!isset($attributes['class'])) {
-            $class = 'menu'.$name;
-            // name may contaion [], which would make an invalid class. e.g. numeric question type editing form, assignment quickgrading
+            $class = 'menu' . $name;
+            // Name may contain [], which would make an invalid class. e.g. numeric question type editing form, assignment quickgrading.
             $class = str_replace('[', '', $class);
             $class = str_replace(']', '', $class);
             $attributes['class'] = $class;
@@ -300,9 +311,9 @@ class html_writer {
         }
 
         $output = '';
-        foreach ($options as $value=>$label) {
+        foreach ($options as $value => $label) {
             if (is_array($label)) {
-                // ignore key, it just has to be unique
+                // Ignore key, it just has to be unique.
                 $output .= self::select_optgroup(key($label), current($label), $selected);
             } else {
                 $output .= self::select_option($label, $value, $selected);
@@ -320,7 +331,7 @@ class html_writer {
      * @return string HTML fragment
      */
     private static function select_option($label, $value, array $selected) {
-        $attributes = array();
+        $attributes = [];
         $value = (string)$value;
         if (in_array($value, $selected, true)) {
             $attributes['selected'] = 'selected';
@@ -341,9 +352,9 @@ class html_writer {
         if (empty($options)) {
             return '';
         }
-        $attributes = array('label'=>$groupname);
+        $attributes = ['label' => $groupname];
         $output = '';
-        foreach ($options as $value=>$label) {
+        foreach ($options as $value => $label) {
             $output .= self::select_option($label, $value, $selected);
         }
         return self::tag('optgroup', $output, $attributes);
@@ -356,12 +367,12 @@ class html_writer {
      * @param string $name fieldname
      * @param int $currenttime A default timestamp in GMT
      * @param int $step minute spacing
-     * @param array $attributes - html select element attributes
+     * @param null|array $attributes - html select element attributes
      * @param float|int|string $timezone the timezone to use to calculate the time
      *        {@link https://moodledev.io/docs/apis/subsystems/time#timezone}
      * @return string HTML fragment
      */
-    public static function select_time($type, $name, $currenttime = 0, $step = 5, array $attributes = null, $timezone = 99) {
+    public static function select_time($type, $name, $currenttime = 0, $step = 5, ?array $attributes = null, $timezone = 99) {
         global $OUTPUT;
 
         if (!$currenttime) {
@@ -371,7 +382,7 @@ class html_writer {
         $currentdate = $calendartype->timestamp_to_date_array($currenttime, $timezone);
 
         $userdatetype = $type;
-        $timeunits = array();
+        $timeunits = [];
 
         switch ($type) {
             case 'years':
@@ -388,17 +399,17 @@ class html_writer {
                 $userdatetype = 'mday';
                 break;
             case 'hours':
-                for ($i=0; $i<=23; $i++) {
-                    $timeunits[$i] = sprintf("%02d",$i);
+                for ($i = 0; $i <= 23; $i++) {
+                    $timeunits[$i] = sprintf("%02d", $i);
                 }
                 break;
             case 'minutes':
                 if ($step != 1) {
-                    $currentdate['minutes'] = ceil($currentdate['minutes']/$step)*$step;
+                    $currentdate['minutes'] = ceil($currentdate['minutes'] / $step) * $step;
                 }
 
-                for ($i=0; $i<=59; $i+=$step) {
-                    $timeunits[$i] = sprintf("%02d",$i);
+                for ($i = 0; $i <= 59; $i += $step) {
+                    $timeunits[$i] = sprintf("%02d", $i);
                 }
                 break;
             default:
@@ -410,21 +421,21 @@ class html_writer {
             'name' => $name,
             'id' => !empty($attributes['id']) ? $attributes['id'] : self::random_id('ts_'),
             'label' => get_string(substr($type, 0, -1), 'form'),
-            'options' => array_map(function($value) use ($timeunits, $currentdate, $userdatetype) {
+            'options' => array_map(function ($value) use ($timeunits, $currentdate, $userdatetype) {
                 return [
                     'name' => $timeunits[$value],
                     'value' => $value,
-                    'selected' => $currentdate[$userdatetype] == $value
+                    'selected' => $currentdate[$userdatetype] == $value,
                 ];
             }, array_keys($timeunits)),
         ];
 
         unset($attributes['id']);
         unset($attributes['name']);
-        $data->attributes = array_map(function($name) use ($attributes) {
+        $data->attributes = array_map(function ($name) use ($attributes) {
             return [
                 'name' => $name,
-                'value' => $attributes[$name]
+                'value' => $attributes[$name],
             ];
         }, array_keys($attributes));
 
@@ -437,14 +448,14 @@ class html_writer {
      * Note: 'list' is a reserved keyword ;-)
      *
      * @param array $items
-     * @param array $attributes
+     * @param null|array $attributes
      * @param string $tag ul or ol
      * @return string
      */
-    public static function alist(array $items, array $attributes = null, $tag = 'ul') {
-        $output = self::start_tag($tag, $attributes)."\n";
+    public static function alist(array $items, ?array $attributes = null, $tag = 'ul') {
+        $output = self::start_tag($tag, $attributes) . "\n";
         foreach ($items as $item) {
-            $output .= self::tag('li', $item)."\n";
+            $output .= self::tag('li', $item) . "\n";
         }
         $output .= self::end_tag($tag);
         return $output;
@@ -454,10 +465,10 @@ class html_writer {
      * Returns hidden input fields created from url parameters.
      *
      * @param moodle_url $url
-     * @param array $exclude list of excluded parameters
+     * @param null|array $exclude list of excluded parameters
      * @return string HTML fragment
      */
-    public static function input_hidden_params(moodle_url $url, array $exclude = null) {
+    public static function input_hidden_params(moodle_url $url, ?array $exclude = null) {
         $exclude = (array)$exclude;
         $params = $url->params();
         foreach ($exclude as $key) {
@@ -466,8 +477,8 @@ class html_writer {
 
         $output = '';
         foreach ($params as $key => $value) {
-            $attributes = array('type'=>'hidden', 'name'=>$key, 'value'=>$value);
-            $output .= self::empty_tag('input', $attributes)."\n";
+            $attributes = ['type' => 'hidden', 'name' => $key, 'value' => $value];
+            $output .= self::empty_tag('input', $attributes) . "\n";
         }
         return $output;
     }
@@ -479,13 +490,11 @@ class html_writer {
      * @param moodle_url|string $url optional url of the external script, $code ignored if specified
      * @return string HTML, the code wrapped in <script> tags.
      */
-    public static function script($jscode, $url=null) {
+    public static function script($jscode, $url = null) {
         if ($jscode) {
             return self::tag('script', "\n//<![CDATA[\n$jscode\n//]]>\n") . "\n";
-
         } else if ($url) {
             return self::tag('script', '', ['src' => $url]) . "\n";
-
         } else {
             return '';
         }
@@ -503,11 +512,11 @@ class html_writer {
      * @return string HTML code
      */
     public static function table(html_table $table) {
-        // prepare table data and populate missing properties with reasonable defaults
+        // Prepare table data and populate missing properties with reasonable defaults.
         if (!empty($table->align)) {
             foreach ($table->align as $key => $aa) {
                 if ($aa) {
-                    $table->align[$key] = 'text-align:'. fix_align_rtl($aa) .';';  // Fix for RTL languages
+                    $table->align[$key] = 'text-align:' . fix_align_rtl($aa) . ';';  // Fix for RTL languages.
                 } else {
                     $table->align[$key] = null;
                 }
@@ -516,7 +525,7 @@ class html_writer {
         if (!empty($table->size)) {
             foreach ($table->size as $key => $ss) {
                 if ($ss) {
-                    $table->size[$key] = 'width:'. $ss .';';
+                    $table->size[$key] = 'width:' . $ss . ';';
                 } else {
                     $table->size[$key] = null;
                 }
@@ -542,7 +551,6 @@ class html_writer {
                 if (!isset($table->wrap[$key])) {
                     $table->wrap[$key] = null;
                 }
-
             }
         }
         if (empty($table->attributes['class'])) {
@@ -552,22 +560,22 @@ class html_writer {
             $table->attributes['class'] .= ' boxalign' . $table->tablealign;
         }
 
-        // explicitly assigned properties override those defined via $table->attributes
+        // Explicitly assigned properties override those defined via $table->attributes.
         $table->attributes['class'] = trim($table->attributes['class']);
-        $attributes = array_merge($table->attributes, array(
+        $attributes = array_merge($table->attributes, [
             'id'            => $table->id,
             'width'         => $table->width,
             'summary'       => $table->summary,
             'cellpadding'   => $table->cellpadding,
             'cellspacing'   => $table->cellspacing,
-        ));
+        ]);
         $output = self::start_tag('table', $attributes) . "\n";
 
         $countcols = 0;
 
         // Output a caption if present.
         if (!empty($table->caption)) {
-            $captionattributes = array();
+            $captionattributes = [];
             if ($table->captionhide) {
                 $captionattributes['class'] = 'accesshide';
             }
@@ -581,13 +589,13 @@ class html_writer {
         if (!empty($table->head)) {
             $countcols = count($table->head);
 
-            $output .= self::start_tag('thead', array()) . "\n";
-            $output .= self::start_tag('tr', array()) . "\n";
+            $output .= self::start_tag('thead', []) . "\n";
+            $output .= self::start_tag('tr', []) . "\n";
             $keys = array_keys($table->head);
             $lastkey = end($keys);
 
             foreach ($table->head as $key => $heading) {
-                // Convert plain string headings into html_table_cell objects
+                // Convert plain string headings into html_table_cell objects.
                 if (!($heading instanceof html_table_cell)) {
                     $headingtext = $heading;
                     $heading = new html_table_cell();
@@ -633,9 +641,9 @@ class html_writer {
 
             if (empty($table->data)) {
                 // For valid XHTML strict every table must contain either a valid tr
-                // or a valid tbody... both of which must contain a valid td
-                $output .= self::start_tag('tbody', array('class' => 'empty'));
-                $output .= self::tag('tr', self::tag('td', '', array('colspan'=>count($table->head))));
+                // or a valid tbody... both of which must contain a valid td.
+                $output .= self::start_tag('tbody', ['class' => 'empty']);
+                $output .= self::tag('tr', self::tag('td', '', ['colspan' => count($table->head)]));
                 $output .= self::end_tag('tbody');
             }
         }
@@ -643,13 +651,13 @@ class html_writer {
         if (!empty($table->data)) {
             $keys       = array_keys($table->data);
             $lastrowkey = end($keys);
-            $output .= self::start_tag('tbody', array());
+            $output .= self::start_tag('tbody', []);
 
             foreach ($table->data as $key => $row) {
                 if (($row === 'hr') && ($countcols)) {
-                    $output .= self::tag('td', self::tag('div', '', array('class' => 'tabledivider')), array('colspan' => $countcols));
+                    $output .= self::tag('td', self::tag('div', '', ['class' => 'tabledivider']), ['colspan' => $countcols]);
                 } else {
-                    // Convert array rows to html_table_rows and cell strings to html_table_cell objects
+                    // Convert array rows to html_table_rows and cell strings to html_table_cell objects.
                     if (!($row instanceof html_table_row)) {
                         $newrow = new html_table_row();
 
@@ -672,18 +680,18 @@ class html_writer {
 
                     // Explicitly assigned properties should override those defined in the attributes.
                     $row->attributes['class'] = trim($row->attributes['class']);
-                    $trattributes = array_merge($row->attributes, array(
+                    $trattributes = array_merge($row->attributes, [
                         'id'            => $row->id,
                         'style'         => $row->style,
-                    ));
+                    ]);
                     $output .= self::start_tag('tr', $trattributes) . "\n";
                     $keys2 = array_keys($row->cells);
                     $lastkey = end($keys2);
 
-                    $gotlastkey = false; //flag for sanity checking
+                    $gotlastkey = false; // Flag for sanity checking.
                     foreach ($row->cells as $key => $cell) {
                         if ($gotlastkey) {
-                            //This should never happen. Why do we have a cell after the last cell?
+                            // This should never happen. Why do we have a cell after the last cell?
                             mtrace("A cell with key ($key) was found after the last key ($lastkey)");
                         }
 
@@ -711,14 +719,14 @@ class html_writer {
                         $tdstyle .= isset($table->size[$key]) ? $table->size[$key] : '';
                         $tdstyle .= isset($table->wrap[$key]) ? $table->wrap[$key] : '';
                         $cell->attributes['class'] = trim($cell->attributes['class']);
-                        $tdattributes = array_merge($cell->attributes, array(
+                        $tdattributes = array_merge($cell->attributes, [
                             'style' => $tdstyle . $cell->style,
                             'colspan' => $cell->colspan,
                             'rowspan' => $cell->rowspan,
                             'id' => $cell->id,
                             'abbr' => $cell->abbr,
                             'scope' => $cell->scope,
-                        ));
+                        ]);
                         $tagtype = 'td';
                         if ($cell->header === true) {
                             $tagtype = 'th';
@@ -760,26 +768,26 @@ class html_writer {
      * @param array $attributes to be inserted in the tab, for example array('accesskey' => 'a')
      * @return string HTML of the label element
      */
-    public static function label($text, $for, $colonize = true, array $attributes=array()) {
+    public static function label($text, $for, $colonize = true, array $attributes = []) {
         if (!is_null($for)) {
-            $attributes = array_merge($attributes, array('for' => $for));
+            $attributes = array_merge($attributes, ['for' => $for]);
         }
         $text = trim($text ?? '');
         $label = self::tag('label', $text, $attributes);
 
         // TODO MDL-12192 $colonize disabled for now yet
         // if (!empty($text) and $colonize) {
-        //     // the $text may end with the colon already, though it is bad string definition style
-        //     $colon = get_string('labelsep', 'langconfig');
-        //     if (!empty($colon)) {
-        //         $trimmed = trim($colon);
-        //         if ((substr($text, -strlen($trimmed)) == $trimmed) or (substr($text, -1) == ':')) {
-        //             //debugging('The label text should not end with colon or other label separator,
-        //             //           please fix the string definition.', DEBUG_DEVELOPER);
-        //         } else {
-        //             $label .= $colon;
-        //         }
-        //     }
+        // the $text may end with the colon already, though it is bad string definition style
+        // $colon = get_string('labelsep', 'langconfig');
+        // if (!empty($colon)) {
+        // $trimmed = trim($colon);
+        // if ((substr($text, -strlen($trimmed)) == $trimmed) or (substr($text, -1) == ':')) {
+        // debugging('The label text should not end with colon or other label separator,
+        // please fix the string definition.', DEBUG_DEVELOPER);
+        // } else {
+        // $label .= $colon;
+        // }
+        // }
         // }
 
         return $label;
@@ -793,12 +801,12 @@ class html_writer {
      * class parameter, the two values are combined with a space between.
      *
      * @param string $class Optional CSS class (or classes as space-separated list)
-     * @param array $attributes Optional other attributes as array
+     * @param null|array $attributes Optional other attributes as array
      * @return array Attributes (or null if still none)
      */
-    private static function add_class($class = '', array $attributes = null) {
+    private static function add_class($class = '', ?array $attributes = null) {
         if ($class !== '') {
-            $classattribute = array('class' => $class);
+            $classattribute = ['class' => $class];
             if ($attributes) {
                 if (array_key_exists('class', $attributes)) {
                     $attributes['class'] = trim($attributes['class'] . ' ' . $class);
@@ -817,10 +825,10 @@ class html_writer {
      *
      * @param string $content HTML content of tag
      * @param string $class Optional CSS class (or classes as space-separated list)
-     * @param array $attributes Optional other attributes as array
+     * @param null|array $attributes Optional other attributes as array
      * @return string HTML code for div
      */
-    public static function div($content, $class = '', array $attributes = null) {
+    public static function div($content, $class = '', ?array $attributes = null) {
         return self::tag('div', $content, self::add_class($class, $attributes));
     }
 
@@ -828,10 +836,10 @@ class html_writer {
      * Starts a <div> tag. (Shortcut function.)
      *
      * @param string $class Optional CSS class (or classes as space-separated list)
-     * @param array $attributes Optional other attributes as array
+     * @param null|array $attributes Optional other attributes as array
      * @return string HTML code for open div tag
      */
-    public static function start_div($class = '', array $attributes = null) {
+    public static function start_div($class = '', ?array $attributes = null) {
         return self::start_tag('div', self::add_class($class, $attributes));
     }
 
@@ -849,10 +857,10 @@ class html_writer {
      *
      * @param string $content HTML content of tag
      * @param string $class Optional CSS class (or classes as space-separated list)
-     * @param array $attributes Optional other attributes as array
+     * @param null|array $attributes Optional other attributes as array
      * @return string HTML code for span
      */
-    public static function span($content, $class = '', array $attributes = null) {
+    public static function span($content, $class = '', ?array $attributes = null) {
         return self::tag('span', $content, self::add_class($class, $attributes));
     }
 
@@ -860,10 +868,10 @@ class html_writer {
      * Starts a <span> tag. (Shortcut function.)
      *
      * @param string $class Optional CSS class (or classes as space-separated list)
-     * @param array $attributes Optional other attributes as array
+     * @param null|array $attributes Optional other attributes as array
      * @return string HTML code for open span tag
      */
-    public static function start_span($class = '', array $attributes = null) {
+    public static function start_span($class = '', ?array $attributes = null) {
         return self::start_tag('span', self::add_class($class, $attributes));
     }
 
diff --git a/lib/classes/output/icon_system_font.php b/lib/classes/output/icon_system_font.php
index 08a8273dd66..a7ef86e3d43 100644
--- a/lib/classes/output/icon_system_font.php
+++ b/lib/classes/output/icon_system_font.php
@@ -25,8 +25,6 @@
 
 namespace core\output;
 
-defined('MOODLE_INTERNAL') || die();
-
 /**
  * Class allowing different systems for mapping and rendering icons.
  *
@@ -41,6 +39,4 @@ defined('MOODLE_INTERNAL') || die();
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 abstract class icon_system_font extends icon_system {
-
 }
-
diff --git a/lib/classes/output/icon_system_fontawesome.php b/lib/classes/output/icon_system_fontawesome.php
index 0b9053a2590..88b10d6e23b 100644
--- a/lib/classes/output/icon_system_fontawesome.php
+++ b/lib/classes/output/icon_system_fontawesome.php
@@ -30,7 +30,6 @@ namespace core\output;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class icon_system_fontawesome extends icon_system_font {
-
     /**
      * @var array $map Cached map of moodle icon names to font awesome icon names.
      */
@@ -459,7 +458,7 @@ class icon_system_fontawesome extends icon_system_font {
 
             // Create different mapping keys for different icon system classes, there may be several different
             // themes on the same site.
-            $mapkey = 'mapping_'.preg_replace('/[^a-zA-Z0-9_]/', '_', get_class($this));
+            $mapkey = 'mapping_' . preg_replace('/[^a-zA-Z0-9_]/', '_', get_class($this));
             $this->map = $cache->get($mapkey);
 
             if (empty($this->map)) {
@@ -476,16 +475,16 @@ class icon_system_fontawesome extends icon_system_font {
                 }
                 $cache->set($mapkey, $this->map);
             }
-
         }
         return $this->map;
     }
 
-
+    #[\Override]
     public function get_amd_name() {
         return 'core/icon_system_fontawesome';
     }
 
+    #[\Override]
     public function render_pix_icon(renderer_base $output, pix_icon $icon) {
         $subtype = 'pix_icon_fontawesome';
         $subpix = new $subtype($icon);
@@ -507,5 +506,4 @@ class icon_system_fontawesome extends icon_system_font {
 
         return $output->render_from_template('core/pix_icon_fontawesome', $data);
     }
-
 }
diff --git a/lib/classes/output/icon_system_standard.php b/lib/classes/output/icon_system_standard.php
index cc0d1500915..9e5e49a2414 100644
--- a/lib/classes/output/icon_system_standard.php
+++ b/lib/classes/output/icon_system_standard.php
@@ -25,13 +25,14 @@ namespace core\output;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class icon_system_standard extends icon_system {
+    #[\Override]
     public function render_pix_icon(renderer_base $output, pix_icon $icon) {
         $data = $icon->export_for_template($output);
         return $output->render_from_template('core/pix_icon', $data);
     }
 
+    #[\Override]
     public function get_amd_name() {
         return 'core/icon_system_standard';
     }
-
 }
diff --git a/lib/classes/output/initials_bar.php b/lib/classes/output/initials_bar.php
index 453b843d245..aeec9b56b14 100644
--- a/lib/classes/output/initials_bar.php
+++ b/lib/classes/output/initials_bar.php
@@ -124,7 +124,7 @@ class initials_bar implements renderable, templatable {
             $groupletter = new stdClass();
             $groupletter->name = $letter;
             if (!$this->minirender) {
-                $groupletter->url = $this->url->out(false, array($this->urlvar => $letter));
+                $groupletter->url = $this->url->out(false, [$this->urlvar => $letter]);
             } else {
                 $groupletter->input = $letter;
             }
@@ -140,7 +140,7 @@ class initials_bar implements renderable, templatable {
         $data->class = $this->class;
         $data->title = $this->title;
         if (!$this->minirender) {
-            $data->url = $this->url->out(false, array($this->urlvar => ''));
+            $data->url = $this->url->out(false, [$this->urlvar => '']);
         } else {
             $data->input = 'ALL';
         }
diff --git a/lib/classes/output/inplace_editable.php b/lib/classes/output/inplace_editable.php
index 6c94c474418..302ffe28e79 100644
--- a/lib/classes/output/inplace_editable.php
+++ b/lib/classes/output/inplace_editable.php
@@ -40,7 +40,7 @@ use lang_string;
  * @copyright  2016 Marina Glancy
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class inplace_editable implements templatable, renderable {
+class inplace_editable implements renderable, templatable {
     /**
      * @var string component responsible for diplsying/updating
      */
@@ -101,7 +101,8 @@ class inplace_editable implements templatable, renderable {
      * Constructor.
      *
      * @param string $component name of the component or plugin responsible for the updating of the value (must declare callback)
-     * @param string $itemtype type of the item inside the component - each component/plugin may implement multiple inplace-editable elements
+     * @param string $itemtype type of the item inside the component
+     *                         Each component/plugin may implement multiple inplace-editable elements.
      * @param int $itemid identifier of the item that can be edited in-place
      * @param bool $editable whether this value is editable (check capabilities and editing mode), if false, only "displayvalue"
      *              will be displayed without anything else
@@ -112,8 +113,17 @@ class inplace_editable implements templatable, renderable {
      * @param lang_string|string $editlabel label for the input element in the editing mode (for screenreaders)
      * @param pix_icon|null $editicon icon to use to toggle editing
      */
-    public function __construct($component, $itemtype, $itemid, $editable,
-            $displayvalue, $value = null, $edithint = null, $editlabel = null, ?pix_icon $editicon = null) {
+    public function __construct(
+        $component,
+        $itemtype,
+        $itemid,
+        $editable,
+        $displayvalue,
+        $value = null,
+        $edithint = null,
+        $editlabel = null,
+        ?pix_icon $editicon = null
+    ) {
         $this->component = $component;
         $this->itemtype = $itemtype;
         $this->itemid = $itemid;
@@ -138,7 +148,7 @@ class inplace_editable implements templatable, renderable {
      */
     public function set_type_toggle($options = null) {
         if ($options === null) {
-            $options = array(0, 1);
+            $options = [0, 1];
         }
         $options = array_values($options);
         $idx = array_search($this->value, $options, true);
@@ -235,16 +245,16 @@ class inplace_editable implements templatable, renderable {
      */
     public function export_for_template(\renderer_base $output) {
         if (!$this->editable) {
-            return array(
-                'displayvalue' => (string)$this->displayvalue
-            );
+            return [
+                'displayvalue' => (string)$this->displayvalue,
+            ];
         }
 
         if ($this->editicon === null) {
             $this->editicon = new pix_icon('t/editstring', (string) $this->edithint);
         }
 
-        return array(
+        return [
             'component' => $this->component,
             'itemtype' => $this->itemtype,
             'itemid' => $this->itemid,
@@ -256,7 +266,7 @@ class inplace_editable implements templatable, renderable {
             'type' => $this->type,
             'options' => $this->options,
             'linkeverything' => $this->get_linkeverything() ? 1 : 0,
-        );
+        ];
     }
 
     /**
diff --git a/lib/classes/output/js_writer.php b/lib/classes/output/js_writer.php
index a98d078b980..9095a91cd8a 100644
--- a/lib/classes/output/js_writer.php
+++ b/lib/classes/output/js_writer.php
@@ -30,11 +30,11 @@ class js_writer {
      * Returns javascript code calling the function
      *
      * @param string $function function name, can be complex like Y.Event.purgeElement
-     * @param array $arguments parameters
+     * @param null|array $arguments parameters
      * @param int $delay execution delay in seconds
      * @return string JS code fragment
      */
-    public static function function_call($function, array $arguments = null, $delay=0) {
+    public static function function_call($function, ?array $arguments = null, $delay = 0) {
         if ($arguments) {
             $arguments = array_map('json_encode', convert_to_array($arguments));
             $arguments = implode(', ', $arguments);
@@ -44,7 +44,7 @@ class js_writer {
         $js = "$function($arguments);";
 
         if ($delay) {
-            $delay = $delay * 1000; // in miliseconds
+            $delay = $delay * 1000; // Delay in miliseconds.
             $js = "setTimeout(function() { $js }, $delay);";
         }
         return $js . "\n";
@@ -54,10 +54,10 @@ class js_writer {
      * Special function which adds Y as first argument of function call.
      *
      * @param string $function The function to call
-     * @param array $extraarguments Any arguments to pass to it
+     * @param null|array $extraarguments Any arguments to pass to it
      * @return string Some JS code
      */
-    public static function function_call_with_Y($function, array $extraarguments = null) {
+    public static function function_call_with_y($function, ?array $extraarguments = null) {
         if ($extraarguments) {
             $extraarguments = array_map('json_encode', convert_to_array($extraarguments));
             $arguments = 'Y, ' . implode(', ', $extraarguments);
@@ -72,12 +72,12 @@ class js_writer {
      *
      * @param string $var If it is null then no var is assigned the new object.
      * @param string $class The class to initialise an object for.
-     * @param array $arguments An array of args to pass to the init method.
-     * @param array $requirements Any modules required for this class.
+     * @param null|array $arguments An array of args to pass to the init method.
+     * @param null|array $requirements Any modules required for this class.
      * @param int $delay The delay before initialisation. 0 = no delay.
      * @return string Some JS code
      */
-    public static function object_init($var, $class, array $arguments = null, array $requirements = null, $delay=0) {
+    public static function object_init($var, $class, ?array $arguments = null, ?array $requirements = null, $delay = 0) {
         if (is_array($arguments)) {
             $arguments = array_map('json_encode', convert_to_array($arguments));
             $arguments = implode(', ', $arguments);
@@ -85,14 +85,14 @@ class js_writer {
 
         if ($var === null) {
             $js = "new $class(Y, $arguments);";
-        } else if (strpos($var, '.')!==false) {
+        } else if (strpos($var, '.') !== false) {
             $js = "$var = new $class(Y, $arguments);";
         } else {
             $js = "var $var = new $class(Y, $arguments);";
         }
 
         if ($delay) {
-            $delay = $delay * 1000; // in miliseconds
+            $delay = $delay * 1000; // Delay in miliseconds.
             $js = "setTimeout(function() { $js }, $delay);";
         }
 
@@ -100,7 +100,7 @@ class js_writer {
             $requirements = implode("', '", $requirements);
             $js = "Y.use('$requirements', function(Y){ $js });";
         }
-        return $js."\n";
+        return $js . "\n";
     }
 
     /**
@@ -122,7 +122,7 @@ class js_writer {
             }
         }
 
-        $output .= "$name = ".json_encode($value).";";
+        $output .= "$name = " . json_encode($value) . ";";
 
         return $output;
     }
@@ -134,10 +134,10 @@ class js_writer {
      *     array or string, element id is in the form "#idvalue"
      * @param string $event A valid DOM event (click, mousedown, change etc.)
      * @param string $function The name of the function to call
-     * @param array $arguments An optional array of argument parameters to pass to the function
+     * @param null|array $arguments An optional array of argument parameters to pass to the function
      * @return string JS code fragment
      */
-    public static function event_handler($selector, $event, $function, array $arguments = null) {
+    public static function event_handler($selector, $event, $function, ?array $arguments = null) {
         $selector = json_encode($selector);
         $output = "Y.on('$event', $function, $selector, null";
         if (!empty($arguments)) {
diff --git a/lib/classes/output/language_menu.php b/lib/classes/output/language_menu.php
index c45ed734478..58304899cff 100644
--- a/lib/classes/output/language_menu.php
+++ b/lib/classes/output/language_menu.php
@@ -34,7 +34,6 @@ namespace core\output;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class language_menu implements renderable, templatable {
-
     /** @var \moodle_page $page the moodle page that the languague menu belongs to */
     protected $page;
 
@@ -67,7 +66,7 @@ class language_menu implements renderable, templatable {
             return false;
         }
 
-        if ($this->page->course != SITEID and !empty($this->page->course->lang)) {
+        if ($this->page->course != SITEID && !empty($this->page->course->lang)) {
             // Do not show lang menu if language forced.
             return false;
         }
@@ -175,5 +174,4 @@ class language_menu implements renderable, templatable {
         $singleselect->class = 'langmenu';
         return $singleselect->export_for_template($output);
     }
-
 }
diff --git a/lib/classes/output/local/action_menu/subpanel.php b/lib/classes/output/local/action_menu/subpanel.php
index d0a92624c3a..9724ea8f4c4 100644
--- a/lib/classes/output/local/action_menu/subpanel.php
+++ b/lib/classes/output/local/action_menu/subpanel.php
@@ -24,7 +24,7 @@ use stdClass;
 /**
  * Interface to a subpanel implementation.
  *
- * @package    core_admin
+ * @package    core
  * @copyright  2023 Ferran Recio <ferran@moodle.com>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
diff --git a/lib/classes/output/local/dropdown/status.php b/lib/classes/output/local/dropdown/status.php
index 98381e1ea96..34ccf0d5e55 100644
--- a/lib/classes/output/local/dropdown/status.php
+++ b/lib/classes/output/local/dropdown/status.php
@@ -30,7 +30,6 @@ use core\output\choicelist;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class status extends dialog {
-
     /**
      * @var choicelist content of dialog.
      */
diff --git a/lib/classes/output/mustache_clean_string_helper.php b/lib/classes/output/mustache_clean_string_helper.php
index a067490ca18..3cda336720b 100644
--- a/lib/classes/output/mustache_clean_string_helper.php
+++ b/lib/classes/output/mustache_clean_string_helper.php
@@ -27,7 +27,6 @@ use Mustache_LambdaHelper;
  * @since      4.0
  */
 class mustache_clean_string_helper {
-
     /** @var mustache_string_helper A string helper instance that is being used internally for fetching strings */
     private $stringhelper;
 
diff --git a/lib/classes/output/mustache_engine.php b/lib/classes/output/mustache_engine.php
index 60a7933e74e..5bea960264d 100644
--- a/lib/classes/output/mustache_engine.php
+++ b/lib/classes/output/mustache_engine.php
@@ -19,6 +19,7 @@
  *
  * @copyright  2019 Ryan Wyllie <ryan@moodle.com>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @package core
  */
 
 namespace core\output;
@@ -28,6 +29,7 @@ namespace core\output;
  *
  * @copyright  2019 Ryan Wyllie <ryan@moodle.com>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @package core
  */
 class mustache_engine extends \Mustache_Engine {
     /**
@@ -72,8 +74,7 @@ class mustache_engine extends \Mustache_Engine {
      *
      * @return \Mustache_HelperCollection
      */
-    public function getHelpers()
-    {
+    public function gethelpers() {
         if (!isset($this->helpers)) {
             $this->helpers = new mustache_helper_collection(null, $this->disallowednestedhelpers);
         }
diff --git a/lib/classes/output/mustache_filesystem_loader.php b/lib/classes/output/mustache_filesystem_loader.php
index 84266836b8c..bebebc1dcfe 100644
--- a/lib/classes/output/mustache_filesystem_loader.php
+++ b/lib/classes/output/mustache_filesystem_loader.php
@@ -25,7 +25,6 @@ namespace core\output;
  * @since      2.9
  */
 class mustache_filesystem_loader extends \Mustache_Loader_FilesystemLoader {
-
     /**
      * Provide a default no-args constructor (we don't really need anything).
      */
@@ -39,7 +38,7 @@ class mustache_filesystem_loader extends \Mustache_Loader_FilesystemLoader {
      * @param string $name
      * @return string Template file name
      */
-    protected function getFileName($name) {
+    protected function getfilename($name) {
         // Call the Moodle template finder.
         return mustache_template_finder::get_template_filepath($name);
     }
@@ -52,7 +51,7 @@ class mustache_filesystem_loader extends \Mustache_Loader_FilesystemLoader {
      *
      * @return bool Whether to check `is_dir` and `file_exists`
      */
-    protected function shouldCheckPath() {
+    protected function shouldcheckpath() {
         return true;
     }
 
diff --git a/lib/classes/output/mustache_helper_collection.php b/lib/classes/output/mustache_helper_collection.php
index 2a6f33213a7..092ecbf29da 100644
--- a/lib/classes/output/mustache_helper_collection.php
+++ b/lib/classes/output/mustache_helper_collection.php
@@ -24,7 +24,6 @@ namespace core\output;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class mustache_helper_collection extends \Mustache_HelperCollection {
-
     /**
      * @var string[] Names of helpers that aren't allowed to be called within other helpers.
      */
@@ -67,7 +66,7 @@ class mustache_helper_collection extends \Mustache_HelperCollection {
         $disallowedlist = $this->disallowednestedhelpers;
 
         if (is_callable($helper) && !empty($disallowedlist)) {
-            $helper = function($source, \Mustache_LambdaHelper $lambdahelper) use ($helper, $disallowedlist) {
+            $helper = function ($source, \Mustache_LambdaHelper $lambdahelper) use ($helper, $disallowedlist) {
 
                 // Temporarily override the disallowed helpers to return nothing
                 // so that they can't be executed from within other helpers.
@@ -105,7 +104,7 @@ class mustache_helper_collection extends \Mustache_HelperCollection {
                 $function = $this->get($name);
                 // Null out the helper. Must call parent::add here to avoid
                 // a recursion problem.
-                parent::add($name, function() {
+                parent::add($name, function () {
                     return '';
                 });
 
@@ -149,11 +148,11 @@ class mustache_helper_collection extends \Mustache_HelperCollection {
             $endtoken = '\/';
         }
 
-        $regexes = array_map(function($name) use ($starttoken, $endtoken) {
+        $regexes = array_map(function ($name) use ($starttoken, $endtoken) {
             // We only strip out the name of the helper (excluding delimiters)
             // the user is able to change the delimeters on a per template
             // basis so they may not be curly braces.
-            return '/\s*' . $starttoken . '\s*'. $name . '\W+.*' . $endtoken . '\s*' . $name . '\s*/';
+            return '/\s*' . $starttoken . '\s*' . $name . '\W+.*' . $endtoken . '\s*' . $name . '\s*/';
         }, $disallowedlist);
 
         // This will strip out unwanted helpers from the $source string
@@ -163,7 +162,7 @@ class mustache_helper_collection extends \Mustache_HelperCollection {
         // "core, move, {{#js}} some nasty JS hack {{/js}}"
         // After:
         // "core, move, {{}}".
-        return preg_replace_callback($regexes, function() {
+        return preg_replace_callback($regexes, function () {
             return '';
         }, $string);
     }
diff --git a/lib/classes/output/mustache_javascript_helper.php b/lib/classes/output/mustache_javascript_helper.php
index cf163b67a64..eb3ce6df69f 100644
--- a/lib/classes/output/mustache_javascript_helper.php
+++ b/lib/classes/output/mustache_javascript_helper.php
@@ -25,7 +25,6 @@ namespace core\output;
  * @since      2.9
  */
 class mustache_javascript_helper {
-
     /** @var \moodle_page $page - Page used to get requirement manager */
     private $page = null;
 
diff --git a/lib/classes/output/mustache_quote_helper.php b/lib/classes/output/mustache_quote_helper.php
index 5cb9cbad918..3ecca9e1016 100644
--- a/lib/classes/output/mustache_quote_helper.php
+++ b/lib/classes/output/mustache_quote_helper.php
@@ -32,7 +32,6 @@ namespace core\output;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class mustache_quote_helper {
-
     /**
      * Wrap content in quotes, and escape all special JSON characters used.
      *
diff --git a/lib/classes/output/mustache_shorten_text_helper.php b/lib/classes/output/mustache_shorten_text_helper.php
index 510ca472117..b7151fa985f 100644
--- a/lib/classes/output/mustache_shorten_text_helper.php
+++ b/lib/classes/output/mustache_shorten_text_helper.php
@@ -26,7 +26,6 @@ use Mustache_LambdaHelper;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class mustache_shorten_text_helper {
-
     /**
      * Read a length and text component from the string.
      *
@@ -40,7 +39,7 @@ class mustache_shorten_text_helper {
      */
     public function shorten($args, Mustache_LambdaHelper $helper) {
         // Split the text into an array of variables.
-        list($length, $text) = explode(',', $args, 2);
+        [$length, $text] = explode(',', $args, 2);
         $length = trim($length);
         $text = trim($text);
 
diff --git a/lib/classes/output/mustache_string_helper.php b/lib/classes/output/mustache_string_helper.php
index f0d78c24d93..453c49a970b 100644
--- a/lib/classes/output/mustache_string_helper.php
+++ b/lib/classes/output/mustache_string_helper.php
@@ -25,9 +25,9 @@ use stdClass;
  * @copyright  2015 Damyon Wiese
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since      2.9
+ * @package core
  */
 class mustache_string_helper {
-
     /**
      * Read a lang string from a template and get it from get_string.
      *
diff --git a/lib/classes/output/mustache_template_finder.php b/lib/classes/output/mustache_template_finder.php
index babc77d1e8d..e10f9c6246e 100644
--- a/lib/classes/output/mustache_template_finder.php
+++ b/lib/classes/output/mustache_template_finder.php
@@ -26,6 +26,7 @@ use core_component;
  * @copyright  2015 Damyon Wiese
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since      2.9
+ * @package core
  */
 class mustache_template_finder {
     /**
@@ -48,14 +49,14 @@ class mustache_template_finder {
         $themename = clean_param($themename, PARAM_COMPONENT);
 
         // Validate the component.
-        $dirs = array();
+        $dirs = [];
         $compdirectory = core_component::get_component_directory($component);
         if (!$compdirectory) {
             throw new coding_exception("Component was not valid: " . s($component));
         }
 
         // Find the parent themes.
-        $parents = array();
+        $parents = [];
         if ($themename === $PAGE->theme->name) {
             $parents = $PAGE->theme->parents;
         } else {
@@ -97,7 +98,7 @@ class mustache_template_finder {
                                        ' (' . s($name) . ' requested) ');
         }
 
-        list($component, $templatename) = explode('/', $name, 2);
+        [$component, $templatename] = explode('/', $name, 2);
         $component = clean_param($component, PARAM_COMPONENT);
 
         $dirs = self::get_template_directories_for_component($component, $themename);
diff --git a/lib/classes/output/mustache_template_source_loader.php b/lib/classes/output/mustache_template_source_loader.php
index 9c054a38643..d5cb7e5a621 100644
--- a/lib/classes/output/mustache_template_source_loader.php
+++ b/lib/classes/output/mustache_template_source_loader.php
@@ -16,16 +16,16 @@
 
 namespace core\output;
 
-use \Mustache_Tokenizer;
+use Mustache_Tokenizer;
 
 /**
  * Load template source strings.
  *
  * @copyright  2018 Ryan Wyllie <ryan@moodle.com>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @package core
  */
 class mustache_template_source_loader {
-
     /** @var $gettemplatesource Callback function to load the template source from full name */
     private $gettemplatesource = null;
 
@@ -44,7 +44,7 @@ class mustache_template_source_loader {
             $this->gettemplatesource = $gettemplatesource;
         } else {
             // By default we will pull the template from disk.
-            $this->gettemplatesource = function($component, $name, $themename) {
+            $this->gettemplatesource = function ($component, $name, $themename) {
                 $fulltemplatename = $component . '/' . $name;
                 $filename = mustache_template_finder::get_template_filepath($fulltemplatename, $themename);
                 return file_get_contents($filename);
@@ -150,7 +150,7 @@ class mustache_template_source_loader {
         // Get the requested template source.
         $templatesource = $this->load($templatecomponent, $templatename, $themename, $includecomments);
         // This is a helper function to save a value in one of the result arrays (either $templates or $strings).
-        $save = function(array $results, array $seenlist, string $component, string $id, $value) use ($lang) {
+        $save = function (array $results, array $seenlist, string $component, string $id, $value) use ($lang) {
             if (!isset($results[$component])) {
                 // If the results list doesn't already contain this component then initialise it.
                 $results[$component] = [];
@@ -165,7 +165,7 @@ class mustache_template_source_loader {
         };
         // This is a helper function for processing a dependency. Does stuff like ignore duplicate processing,
         // common result formatting etc.
-        $handler = function(array $dependency, array $ignorelist, callable $processcallback) use ($lang) {
+        $handler = function (array $dependency, array $ignorelist, callable $processcallback) use ($lang) {
             foreach ($dependency as $component => $ids) {
                 foreach ($ids as $id) {
                     $dependencyid = "$component/$id";
@@ -182,7 +182,7 @@ class mustache_template_source_loader {
         };
 
         // Save this template as the first result in the $templates result array.
-        list($templates, $seentemplates) = $save($templates, $seentemplates, $templatecomponent, $templatename, $templatesource);
+        [$templates, $seentemplates] = $save($templates, $seentemplates, $templatecomponent, $templatename, $templatesource);
 
         // Check the template for any dependencies that need to be loaded.
         $dependencies = $this->scan_template_source_for_dependencies($templatesource);
@@ -194,10 +194,10 @@ class mustache_template_source_loader {
             $seenstrings,
             // Include $strings and $seenstrings by reference so that their values can be updated
             // outside of this anonymous function.
-            function($component, $id) use ($save, &$strings, &$seenstrings, $lang) {
+            function ($component, $id) use ($save, &$strings, &$seenstrings, $lang) {
                 $string = get_string_manager()->get_string($id, $component, null, $lang);
                 // Save the string in the $strings results array.
-                list($strings, $seenstrings) = $save($strings, $seenstrings, $component, $id, $string);
+                [$strings, $seenstrings] = $save($strings, $seenstrings, $component, $id, $string);
             }
         );
 
@@ -208,7 +208,10 @@ class mustache_template_source_loader {
             $seentemplates,
             // Include $strings, $seenstrings, $templates, and $seentemplates by reference so that their values can be updated
             // outside of this anonymous function.
-            function($component, $id) use (
+            function (
+                $component,
+                $id
+            ) use (
                 $themename,
                 $includecomments,
                 &$seentemplates,
@@ -232,14 +235,14 @@ class mustache_template_source_loader {
                 foreach ($subdependencies['templates'] as $component => $ids) {
                     foreach ($ids as $id => $value) {
                         // Include the child themes in our results.
-                        list($templates, $seentemplates) = $save($templates, $seentemplates, $component, $id, $value);
+                        [$templates, $seentemplates] = $save($templates, $seentemplates, $component, $id, $value);
                     }
                 };
 
                 foreach ($subdependencies['strings'] as $component => $ids) {
                     foreach ($ids as $id => $value) {
                         // Include any strings that the child templates need in our results.
-                        list($strings, $seenstrings) = $save($strings, $seenstrings, $component, $id, $value);
+                        [$strings, $seenstrings] = $save($strings, $seenstrings, $component, $id, $value);
                     }
                 }
             }
@@ -247,7 +250,7 @@ class mustache_template_source_loader {
 
         return [
             'templates' => $templates,
-            'strings' => $strings
+            'strings' => $strings,
         ];
     }
 
@@ -280,7 +283,7 @@ class mustache_template_source_loader {
         $tokens = $tokenizer->scan($source);
         $templates = [];
         $strings = [];
-        $addtodependencies = function($dependencies, $component, $id) {
+        $addtodependencies = function ($dependencies, $component, $id) {
             $id = trim($id);
             $component = trim($component);
 
@@ -302,16 +305,16 @@ class mustache_template_source_loader {
             if ($name) {
                 switch ($type) {
                     case Mustache_Tokenizer::T_PARTIAL:
-                        list($component, $id) = explode('/', $name, 2);
+                        [$component, $id] = explode('/', $name, 2);
                         $templates = $addtodependencies($templates, $component, $id);
                         break;
                     case Mustache_Tokenizer::T_PARENT:
-                        list($component, $id) = explode('/', $name, 2);
+                        [$component, $id] = explode('/', $name, 2);
                         $templates = $addtodependencies($templates, $component, $id);
                         break;
                     case Mustache_Tokenizer::T_SECTION:
                         if ($name == 'str') {
-                            list($id, $component) = $this->get_string_identifiers($tokens, $index);
+                            [$id, $component] = $this->get_string_identifiers($tokens, $index);
 
                             if ($id) {
                                 $strings = $addtodependencies($strings, $component, $id);
@@ -324,7 +327,7 @@ class mustache_template_source_loader {
 
         return [
             'templates' => $templates,
-            'strings' => $strings
+            'strings' => $strings,
         ];
     }
 
diff --git a/lib/classes/output/mustache_uniqid_helper.php b/lib/classes/output/mustache_uniqid_helper.php
index 0dbb773e9ca..28c3272c81f 100644
--- a/lib/classes/output/mustache_uniqid_helper.php
+++ b/lib/classes/output/mustache_uniqid_helper.php
@@ -34,7 +34,6 @@ namespace core\output;
  * @since      2.9
  */
 class mustache_uniqid_helper {
-
     /** @var string $uniqid The unique id */
     private $uniqid = null;
 
diff --git a/lib/classes/output/mustache_user_date_helper.php b/lib/classes/output/mustache_user_date_helper.php
index 5ff809a1f1f..a087624ec67 100644
--- a/lib/classes/output/mustache_user_date_helper.php
+++ b/lib/classes/output/mustache_user_date_helper.php
@@ -23,6 +23,7 @@ use Mustache_LambdaHelper;
  *
  * @copyright  2017 Ryan Wyllie <ryan@moodle.com>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @package core
  */
 class mustache_user_date_helper {
     /**
@@ -40,7 +41,7 @@ class mustache_user_date_helper {
      */
     public function transform($args, Mustache_LambdaHelper $helper) {
         // Split the text into an array of variables.
-        list($timestamp, $format) = explode(',', $args, 2);
+        [$timestamp, $format] = explode(',', $args, 2);
         $timestamp = trim($timestamp);
         $format = trim($format);
 
diff --git a/lib/classes/output/notification.php b/lib/classes/output/notification.php
index ba74371a730..4226929ae59 100644
--- a/lib/classes/output/notification.php
+++ b/lib/classes/output/notification.php
@@ -34,7 +34,6 @@ namespace core\output;
  * @category output
  */
 class notification implements renderable, templatable {
-
     /**
      * A notification of level 'success'.
      */
@@ -78,7 +77,7 @@ class notification implements renderable, templatable {
     /**
      * @var array $extraclasses A list of any extra classes that may be required.
      */
-    protected $extraclasses = array();
+    protected $extraclasses = [];
 
     /**
      * Notification constructor.
@@ -129,7 +128,7 @@ class notification implements renderable, templatable {
      * @param array $classes
      * @return $this
      */
-    public function set_extra_classes($classes = array()) {
+    public function set_extra_classes($classes = []) {
         $this->extraclasses = $classes;
 
         return $this;
@@ -160,7 +159,7 @@ class notification implements renderable, templatable {
      * @return array data context for a mustache template
      */
     public function export_for_template(\renderer_base $output) {
-        return array(
+        return [
             'message'       => clean_text($this->message),
             'extraclasses'  => implode(' ', $this->extraclasses),
             'announce'      => $this->announce,
@@ -169,9 +168,14 @@ class notification implements renderable, templatable {
             'isinfo'            => $this->messagetype === 'info',
             'iswarning'         => $this->messagetype === 'warning',
             'iserror'           => $this->messagetype === 'error',
-        );
+        ];
     }
 
+    /**
+     * Get the name of the template to use for this templatable.
+     *
+     * @return string
+     */
     public function get_template_name() {
         $templatemappings = [
             // Current types mapped to template names.
diff --git a/lib/classes/output/paging_bar.php b/lib/classes/output/paging_bar.php
index 0d204731dc6..e334885a062 100644
--- a/lib/classes/output/paging_bar.php
+++ b/lib/classes/output/paging_bar.php
@@ -88,7 +88,7 @@ class paging_bar implements renderable, templatable {
     /**
      * @var array An array of strings. One of them is just a string: the current page
      */
-    public $pagelinks = array();
+    public $pagelinks = [];
 
     /**
      * Constructor paging_bar with only the required params.
@@ -136,7 +136,11 @@ class paging_bar implements renderable, templatable {
             $pagenum = $this->page - 1;
 
             if ($this->page > 0) {
-                $this->previouslink = html_writer::link(new moodle_url($this->baseurl, array($this->pagevar=>$pagenum)), get_string('previous'), array('class'=>'previous'));
+                $this->previouslink = html_writer::link(
+                    new moodle_url($this->baseurl, [$this->pagevar => $pagenum]),
+                    get_string('previous'),
+                    ['class' => 'previous'],
+                );
             }
 
             if ($this->perpage > 0) {
@@ -145,23 +149,27 @@ class paging_bar implements renderable, templatable {
                 $lastpage = 1;
             }
 
-            if ($this->page > round(($this->maxdisplay/3)*2)) {
-                $currpage = $this->page - round($this->maxdisplay/3);
+            if ($this->page > round(($this->maxdisplay / 3) * 2)) {
+                $currpage = $this->page - round($this->maxdisplay / 3);
 
-                $this->firstlink = html_writer::link(new moodle_url($this->baseurl, array($this->pagevar=>0)), '1', array('class'=>'first'));
+                $this->firstlink = html_writer::link(
+                    new moodle_url($this->baseurl, [$this->pagevar => 0]),
+                    '1',
+                    ['class' => 'first'],
+                );
             } else {
                 $currpage = 0;
             }
 
             $displaycount = $displaypage = 0;
 
-            while ($displaycount < $this->maxdisplay and $currpage < $lastpage) {
+            while ($displaycount < $this->maxdisplay && $currpage < $lastpage) {
                 $displaypage = $currpage + 1;
 
                 if ($this->page == $currpage) {
                     $this->pagelinks[] = html_writer::span($displaypage, 'current-page');
                 } else {
-                    $pagelink = html_writer::link(new moodle_url($this->baseurl, array($this->pagevar=>$currpage)), $displaypage);
+                    $pagelink = html_writer::link(new moodle_url($this->baseurl, [$this->pagevar => $currpage]), $displaypage);
                     $this->pagelinks[] = $pagelink;
                 }
 
@@ -171,13 +179,21 @@ class paging_bar implements renderable, templatable {
 
             if ($currpage < $lastpage) {
                 $lastpageactual = $lastpage - 1;
-                $this->lastlink = html_writer::link(new moodle_url($this->baseurl, array($this->pagevar=>$lastpageactual)), $lastpage, array('class'=>'last'));
+                $this->lastlink = html_writer::link(
+                    new moodle_url($this->baseurl, [$this->pagevar => $lastpageactual]),
+                    $lastpage,
+                    ['class' => 'last'],
+                );
             }
 
             $pagenum = $this->page + 1;
 
             if ($pagenum != $lastpage) {
-                $this->nextlink = html_writer::link(new moodle_url($this->baseurl, array($this->pagevar=>$pagenum)), get_string('next'), array('class'=>'next'));
+                $this->nextlink = html_writer::link(
+                    new moodle_url($this->baseurl, [$this->pagevar => $pagenum]),
+                    get_string('next'),
+                    ['class' => 'next'],
+                );
             }
         }
     }
@@ -206,7 +222,7 @@ class paging_bar implements renderable, templatable {
         if ($this->page > 0) {
             $data->previous = [
                 'page' => $this->page,
-                'url' => (new moodle_url($this->baseurl, [$this->pagevar => $this->page - 1]))->out(false)
+                'url' => (new moodle_url($this->baseurl, [$this->pagevar => $this->page - 1]))->out(false),
             ];
         }
 
@@ -215,7 +231,7 @@ class paging_bar implements renderable, templatable {
             $currpage = $this->page - round($this->maxdisplay / 3);
             $data->first = [
                 'page' => 1,
-                'url' => (new moodle_url($this->baseurl, [$this->pagevar => 0]))->out(false)
+                'url' => (new moodle_url($this->baseurl, [$this->pagevar => 0]))->out(false),
             ];
         }
 
@@ -226,7 +242,7 @@ class paging_bar implements renderable, templatable {
 
         $displaycount = 0;
         $displaypage = 0;
-        while ($displaycount < $this->maxdisplay and $currpage < $lastpage) {
+        while ($displaycount < $this->maxdisplay && $currpage < $lastpage) {
             $displaypage = $currpage + 1;
 
             $iscurrent = $this->page == $currpage;
@@ -235,7 +251,7 @@ class paging_bar implements renderable, templatable {
             $data->pages[] = [
                 'page' => $displaypage,
                 'active' => $iscurrent,
-                'url' => $iscurrent ? null : $link->out(false)
+                'url' => $iscurrent ? null : $link->out(false),
             ];
 
             $displaycount++;
@@ -245,14 +261,14 @@ class paging_bar implements renderable, templatable {
         if ($currpage < $lastpage) {
             $data->last = [
                 'page' => $lastpage,
-                'url' => (new moodle_url($this->baseurl, [$this->pagevar => $lastpage - 1]))->out(false)
+                'url' => (new moodle_url($this->baseurl, [$this->pagevar => $lastpage - 1]))->out(false),
             ];
         }
 
         if ($this->page + 1 != $lastpage) {
             $data->next = [
                 'page' => $this->page + 2,
-                'url' => (new moodle_url($this->baseurl, [$this->pagevar => $this->page + 1]))->out(false)
+                'url' => (new moodle_url($this->baseurl, [$this->pagevar => $this->page + 1]))->out(false),
             ];
         }
 
diff --git a/lib/classes/output/participants_action_bar.php b/lib/classes/output/participants_action_bar.php
index 9ddb022a934..0477ff4dfc0 100644
--- a/lib/classes/output/participants_action_bar.php
+++ b/lib/classes/output/participants_action_bar.php
@@ -72,7 +72,7 @@ class participants_action_bar implements renderable {
                 'renameroles',
             ],
             'groups:group' => [
-                'groups'
+                'groups',
             ],
             'permissions:role' => [
                 'override',
@@ -98,8 +98,10 @@ class participants_action_bar implements renderable {
 
         $formattedcontent = [];
         $enrolmentsheading = get_string('enrolments', 'enrol');
-        if ($this->page->context->contextlevel != CONTEXT_MODULE &&
-                $this->page->context->contextlevel != CONTEXT_COURSECAT) {
+        if (
+            $this->page->context->contextlevel != CONTEXT_MODULE &&
+                $this->page->context->contextlevel != CONTEXT_COURSECAT
+        ) {
             // Pre-populate the formatted tertiary nav items with the "Enrolled users" node if user can view the participants page.
             $coursecontext = context_course::instance($this->course->id);
             $canviewparticipants = course_can_view_participants($coursecontext);
@@ -108,14 +110,14 @@ class participants_action_bar implements renderable {
                 $formattedcontent[] = [
                     $enrolmentsheading => [
                         $participantsurl => get_string('enrolledusers', 'enrol'),
-                    ]
+                    ],
                 ];
             }
         }
 
         $nodes = $this->get_ordered_nodes();
         foreach ($nodes as $description => $content) {
-            list($stringid, $location) = explode(':', $description);
+            [$stringid, $location] = explode(':', $description);
             $heading = get_string($stringid, $location);
             $items = [];
             foreach ($content as $key) {
@@ -129,7 +131,7 @@ class participants_action_bar implements renderable {
                         $params = ['id' => $this->course->id];
                         $items += [
                             (new moodle_url('/group/groupings.php', $params))->out() => get_string('groupings', 'group'),
-                            (new moodle_url('/group/overview.php', $params))->out() => get_string('overview', 'group')
+                            (new moodle_url('/group/overview.php', $params))->out() => get_string('overview', 'group'),
                         ];
                     }
                 }
@@ -145,8 +147,10 @@ class participants_action_bar implements renderable {
         }
 
         // If we are accessing a page from a module/category context additional nodes will not be visible.
-        if ($this->page->context->contextlevel != CONTEXT_MODULE &&
-                $this->page->context->contextlevel != CONTEXT_COURSECAT) {
+        if (
+            $this->page->context->contextlevel != CONTEXT_MODULE &&
+                $this->page->context->contextlevel != CONTEXT_COURSECAT
+        ) {
             // Need to do some funky code here to find out if we have added third party navigation nodes.
             $thirdpartynodearray = $this->get_thirdparty_node_array() ?: [];
             $formattedcontent = array_merge($formattedcontent, $thirdpartynodearray);
diff --git a/lib/classes/output/pix_emoticon.php b/lib/classes/output/pix_emoticon.php
index 000092cb596..9b089abe6f7 100644
--- a/lib/classes/output/pix_emoticon.php
+++ b/lib/classes/output/pix_emoticon.php
@@ -33,7 +33,7 @@ class pix_emoticon extends pix_icon implements renderable {
      * @param string $component emoticon image provider
      * @param array $attributes explicit HTML attributes
      */
-    public function __construct($pix, $alt, $component = 'moodle', array $attributes = array()) {
+    public function __construct($pix, $alt, $component = 'moodle', array $attributes = []) {
         if (empty($attributes['class'])) {
             $attributes['class'] = 'emoticon';
         }
diff --git a/lib/classes/output/pix_icon.php b/lib/classes/output/pix_icon.php
index 1ceaaebb585..d01bc06e3b1 100644
--- a/lib/classes/output/pix_icon.php
+++ b/lib/classes/output/pix_icon.php
@@ -26,21 +26,20 @@ namespace core\output;
  * @category output
  */
 class pix_icon implements renderable, templatable {
-
     /**
      * @var string The icon name
      */
-    var $pix;
+    public $pix;
 
     /**
      * @var string The component the icon belongs to.
      */
-    var $component;
+    public $component;
 
     /**
      * @var array An array of attributes to use on the icon
      */
-    var $attributes = array();
+    public $attributes = [];
 
     /**
      * Constructor
@@ -48,9 +47,14 @@ class pix_icon implements renderable, templatable {
      * @param string $pix short icon name
      * @param string $alt The alt text to use for the icon
      * @param string $component component name
-     * @param array $attributes html attributes
+     * @param null|array $attributes html attributes
      */
-    public function __construct($pix, $alt, $component='moodle', array $attributes = null) {
+    public function __construct(
+        $pix,
+        $alt,
+        $component = 'moodle',
+        ?array $attributes = null,
+    ) {
         global $PAGE;
 
         $this->pix = $pix;
@@ -109,18 +113,18 @@ class pix_icon implements renderable, templatable {
         }
 
         $attributes['src'] = $output->image_url($this->pix, $this->component)->out(false);
-        $templatecontext = array();
+        $templatecontext = [];
         foreach ($attributes as $name => $value) {
-            $templatecontext[] = array('name' => $name, 'value' => $value);
+            $templatecontext[] = ['name' => $name, 'value' => $value];
         }
         $title = isset($attributes['title']) ? $attributes['title'] : '';
         if (empty($title)) {
             $title = isset($attributes['alt']) ? $attributes['alt'] : '';
         }
-        $data = array(
+        $data = [
             'attributes' => $templatecontext,
-            'extraclasses' => $extraclasses
-        );
+            'extraclasses' => $extraclasses,
+        ];
 
         return $data;
     }
diff --git a/lib/classes/output/pix_icon_font.php b/lib/classes/output/pix_icon_font.php
index dce04f61462..2366b4c1900 100644
--- a/lib/classes/output/pix_icon_font.php
+++ b/lib/classes/output/pix_icon_font.php
@@ -82,12 +82,12 @@ class pix_icon_font implements templatable {
         if (empty($title)) {
             $title = $alt;
         }
-        $data = array(
+        $data = [
             'extraclasses' => $pixdata['extraclasses'],
             'title' => $title,
             'alt' => $alt,
-            'key' => $this->key
-        );
+            'key' => $this->key,
+        ];
 
         return $data;
     }
diff --git a/lib/classes/output/plugin_renderer_base.php b/lib/classes/output/plugin_renderer_base.php
index df6b94df22d..8d1be78b0f2 100644
--- a/lib/classes/output/plugin_renderer_base.php
+++ b/lib/classes/output/plugin_renderer_base.php
@@ -32,7 +32,7 @@ class plugin_renderer_base extends renderer_base {
     /**
      * @var renderer_base|core_renderer A reference to the current renderer.
      * The renderer provided here will be determined by the page but will in 90%
-     * of cases by the {@link core_renderer}
+     * of cases by the {@see core_renderer}
      */
     protected $output;
 
@@ -124,12 +124,12 @@ class plugin_renderer_base extends renderer_base {
      */
     public function __call($method, $arguments) {
         if (method_exists('renderer_base', $method)) {
-            throw new coding_exception('Protected method called against '.get_class($this).' :: '.$method);
+            throw new coding_exception('Protected method called against ' . get_class($this) . ' :: ' . $method);
         }
         if (method_exists($this->output, $method)) {
-            return call_user_func_array(array($this->output, $method), $arguments);
+            return call_user_func_array([$this->output, $method], $arguments);
         } else {
-            throw new coding_exception('Unknown method called against '.get_class($this).' :: '.$method);
+            throw new coding_exception('Unknown method called against ' . get_class($this) . ' :: ' . $method);
         }
     }
 }
diff --git a/lib/classes/output/progress_bar.php b/lib/classes/output/progress_bar.php
index b0b3476777c..93cb60545e0 100644
--- a/lib/classes/output/progress_bar.php
+++ b/lib/classes/output/progress_bar.php
@@ -35,7 +35,7 @@ use core\exception\coding_exception;
  */
 class progress_bar implements renderable, templatable {
     /** @var string html id */
-    private $html_id;
+    private $htmlid;
     /** @var int total width */
     private $width;
     /** @var int last percentage printed */
@@ -43,7 +43,7 @@ class progress_bar implements renderable, templatable {
     /** @var int time when last printed */
     private $lastupdate = 0;
     /** @var int when did we start printing this */
-    private $time_start = 0;
+    private $timestart = 0;
 
     /**
      * Constructor
@@ -60,9 +60,9 @@ class progress_bar implements renderable, templatable {
         }
 
         if (!empty($htmlid)) {
-            $this->html_id  = $htmlid;
+            $this->htmlid  = $htmlid;
         } else {
-            $this->html_id  = 'pbar_'.uniqid();
+            $this->htmlid  = 'pbar_' . uniqid();
         }
 
         $this->width = $width;
@@ -77,7 +77,7 @@ class progress_bar implements renderable, templatable {
      * @return string id
      */
     public function get_id(): string {
-        return $this->html_id;
+        return $this->htmlid;
     }
 
     /**
@@ -88,7 +88,7 @@ class progress_bar implements renderable, templatable {
     public function create() {
         global $OUTPUT;
 
-        $this->time_start = microtime(true);
+        $this->timestart = microtime(true);
 
         flush();
         echo $OUTPUT->render($this);
@@ -103,21 +103,21 @@ class progress_bar implements renderable, templatable {
      * @return void Echo's output
      * @throws coding_exception
      */
-    private function _update($percent, $msg) {
+    private function update_raw($percent, $msg) {
         global $OUTPUT;
 
-        if (empty($this->time_start)) {
+        if (empty($this->timestart)) {
             throw new coding_exception('You must call create() (or use the $autostart ' .
                 'argument to the constructor) before you try updating the progress bar.');
         }
 
         $estimate = $this->estimate($percent);
 
-        if ($estimate === null) {
+        if ($estimate === null) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedIf
             // Always do the first and last updates.
-        } else if ($estimate == 0) {
+        } else if ($estimate == 0) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedIf
             // Always do the last updates.
-        } else if ($this->lastupdate + 20 < time()) {
+        } else if ($this->lastupdate + 20 < time()) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedIf
             // We must update otherwise browser would time out.
         } else if (round($this->percent, 2) === round($percent, 2)) {
             // No significant change, no need to update anything.
@@ -133,7 +133,7 @@ class progress_bar implements renderable, templatable {
         $this->percent = $percent;
         $this->lastupdate = microtime(true);
 
-        echo $OUTPUT->render_progress_bar_update($this->html_id, $this->percent, $msg, $estimatemsg);
+        echo $OUTPUT->render_progress_bar_update($this->htmlid, $this->percent, $msg, $estimatemsg);
         flush();
     }
 
@@ -153,7 +153,7 @@ class progress_bar implements renderable, templatable {
         if ($pt > 99.99999) {
             return 0; // Nearly done, right?
         }
-        $consumed = microtime(true) - $this->time_start;
+        $consumed = microtime(true) - $this->timestart;
         if ($consumed < 0.001) {
             return null;
         }
@@ -169,7 +169,7 @@ class progress_bar implements renderable, templatable {
      */
     public function update_full($percent, $msg) {
         $percent = max(min($percent, 100), 0);
-        $this->_update($percent, $msg);
+        $this->update_raw($percent, $msg);
     }
 
     /**
@@ -190,7 +190,7 @@ class progress_bar implements renderable, templatable {
     public function restart() {
         $this->percent    = 0;
         $this->lastupdate = 0;
-        $this->time_start = 0;
+        $this->timestart = 0;
     }
 
     /**
@@ -201,7 +201,7 @@ class progress_bar implements renderable, templatable {
      */
     public function export_for_template(renderer_base $output) {
         return [
-            'id' => $this->html_id,
+            'id' => $this->htmlid,
             'width' => $this->width,
         ];
     }
diff --git a/lib/classes/output/renderable.php b/lib/classes/output/renderable.php
index d9a3263dbc6..58419ffd6e7 100644
--- a/lib/classes/output/renderable.php
+++ b/lib/classes/output/renderable.php
@@ -20,11 +20,12 @@ namespace core\output;
  * Interface marking other classes as suitable for renderer_base::render()
  *
  * @copyright 2010 Petr Skoda (skodak) info@skodak.org
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @package core
  * @category output
  */
 interface renderable {
-    // intentionally empty
+    // Intentionally empty.
 }
 
 // Alias this class to the old name.
diff --git a/lib/classes/output/renderer_base.php b/lib/classes/output/renderer_base.php
index faef3897910..00910c3eaab 100644
--- a/lib/classes/output/renderer_base.php
+++ b/lib/classes/output/renderer_base.php
@@ -22,6 +22,7 @@ use core\exception\coding_exception;
 use core\output\actions\component_action;
 use moodle_page;
 use moodle_url;
+use stdClass;
 use Mustache_Exception_UnknownTemplateException;
 
 /**
@@ -104,17 +105,17 @@ class renderer_base {
             // We only expose the variables that are exposed to JS templates.
             $safeconfig = $this->page->requires->get_config_for_javascript($this->page, $this);
 
-            $helpers = array('config' => $safeconfig,
-                             'str' => array($stringhelper, 'str'),
-                             'cleanstr' => array($cleanstringhelper, 'cleanstr'),
-                             'quote' => array($quotehelper, 'quote'),
-                             'js' => array($jshelper, 'help'),
-                             'pix' => array($pixhelper, 'pix'),
-                             'shortentext' => array($shortentexthelper, 'shorten'),
-                             'userdate' => array($userdatehelper, 'transform'),
-                         );
+            $helpers = ['config' => $safeconfig,
+                             'str' => [$stringhelper, 'str'],
+                             'cleanstr' => [$cleanstringhelper, 'cleanstr'],
+                             'quote' => [$quotehelper, 'quote'],
+                             'js' => [$jshelper, 'help'],
+                             'pix' => [$pixhelper, 'pix'],
+                             'shortentext' => [$shortentexthelper, 'shorten'],
+                             'userdate' => [$userdatehelper, 'transform'],
+                         ];
 
-            $this->mustache = new mustache_engine(array(
+            $this->mustache = new mustache_engine([
                 'cache' => $cachedir,
                 'escape' => 's',
                 'loader' => $loader,
@@ -126,8 +127,7 @@ class renderer_base {
                 'disallowednestedhelpers' => ['js'],
                 // Disable lambda rendering - content in helpers is already rendered, no need to render it again.
                 'disable_lambda_rendering' => true,
-            ));
-
+            ]);
         }
 
         return $this->mustache;
@@ -158,6 +158,7 @@ class renderer_base {
      * Simple types are array,stdClass,bool,int,float,string
      *
      * @since 2.9
+     * @param string $templatename The template to render
      * @param array|stdClass $context Context containing data for the template.
      * @return string|boolean
      */
@@ -257,7 +258,7 @@ class renderer_base {
      *
      * This method adds a JS event for the provided component action to the page
      * and then returns the id that the event has been attached to.
-     * If no id has been provided then a new ID is generated by {@link html_writer::random_id()}
+     * If no id has been provided then a new ID is generated by {@see html_writer::random_id()}
      *
      * @param component_action $action
      * @param string $id
@@ -357,8 +358,14 @@ class renderer_base {
         $filepath = ((int) $maxwidth . 'x' . (int) $maxheight) . '/';
 
         // Use $CFG->themerev to prevent browser caching when the file changes.
-        return moodle_url::make_pluginfile_url(context_system::instance()->id, 'core_admin', 'logo', $filepath,
-            theme_get_revision(), $logo);
+        return moodle_url::make_pluginfile_url(
+            context_system::instance()->id,
+            'core_admin',
+            'logo',
+            $filepath,
+            theme_get_revision(),
+            $logo
+        );
     }
 
     /**
@@ -379,8 +386,14 @@ class renderer_base {
         $filepath = ((int) $maxwidth . 'x' . (int) $maxheight) . '/';
 
         // Use $CFG->themerev to prevent browser caching when the file changes.
-        return moodle_url::make_pluginfile_url(context_system::instance()->id, 'core_admin', 'logocompact', $filepath,
-            theme_get_revision(), $logo);
+        return moodle_url::make_pluginfile_url(
+            context_system::instance()->id,
+            'core_admin',
+            'logocompact',
+            $filepath,
+            theme_get_revision(),
+            $logo
+        );
     }
 
     /**
diff --git a/lib/classes/output/renderer_factory/renderer_factory_base.php b/lib/classes/output/renderer_factory/renderer_factory_base.php
index 16009bd8cab..03911db7e02 100644
--- a/lib/classes/output/renderer_factory/renderer_factory_base.php
+++ b/lib/classes/output/renderer_factory/renderer_factory_base.php
@@ -68,15 +68,27 @@ abstract class renderer_factory_base implements renderer_factory_interface {
         }
 
         switch ($target) {
-            case RENDERER_TARGET_CLI: $suffix = '_cli'; break;
-            case RENDERER_TARGET_AJAX: $suffix = '_ajax'; break;
-            case RENDERER_TARGET_TEXTEMAIL: $suffix = '_textemail'; break;
-            case RENDERER_TARGET_HTMLEMAIL: $suffix = '_htmlemail'; break;
-            case RENDERER_TARGET_MAINTENANCE: $suffix = '_maintenance'; break;
-            default: $target = RENDERER_TARGET_GENERAL; $suffix = '';
+            case RENDERER_TARGET_CLI:
+                $suffix = '_cli';
+                break;
+            case RENDERER_TARGET_AJAX:
+                $suffix = '_ajax';
+                break;
+            case RENDERER_TARGET_TEXTEMAIL:
+                $suffix = '_textemail';
+                break;
+            case RENDERER_TARGET_HTMLEMAIL:
+                $suffix = '_htmlemail';
+                break;
+            case RENDERER_TARGET_MAINTENANCE:
+                $suffix = '_maintenance';
+                break;
+            default:
+                $target = RENDERER_TARGET_GENERAL;
+                $suffix = '';
         }
 
-        return array($target, $suffix);
+        return [$target, $suffix];
     }
 
     /**
@@ -102,14 +114,14 @@ abstract class renderer_factory_base implements renderer_factory_interface {
      */
     protected function standard_renderer_classnames($component, $subtype = null) {
         global $CFG; // Needed in included files.
-        $classnames = array();
+        $classnames = [];
 
         // Standardize component name ala frankenstyle.
-        list($plugin, $type) = core_component::normalize_component($component);
+        [$plugin, $type] = core_component::normalize_component($component);
         if ($type === null) {
             $component = $plugin;
         } else {
-            $component = $plugin.'_'.$type;
+            $component = $plugin . '_' . $type;
         }
 
         if ($component !== 'core') {
@@ -121,7 +133,6 @@ abstract class renderer_factory_base implements renderer_factory_interface {
             if (file_exists($rendererfile)) {
                 include_once($rendererfile);
             }
-
         } else if (!empty($subtype)) {
             $coresubsystems = core_component::get_core_subsystems();
             if (!array_key_exists($subtype, $coresubsystems)) { // There may be nulls.
@@ -137,63 +148,63 @@ abstract class renderer_factory_base implements renderer_factory_interface {
 
         if (empty($subtype)) {
             // Theme specific auto-loaded name (only valid when prefixed with the theme name).
-            $classnames[] = array(
+            $classnames[] = [
                 'validwithprefix' => true,
                 'validwithoutprefix' => false,
                 'autoloaded' => true,
-                'classname' => '\\output\\' . $component . '_renderer'
-            );
+                'classname' => '\\output\\' . $component . '_renderer',
+            ];
 
             // Standard autoloaded plugin name (not valid with a prefix).
-            $classnames[] = array(
+            $classnames[] = [
                 'validwithprefix' => false,
                 'validwithoutprefix' => true,
                 'autoloaded' => true,
-                'classname' => '\\' . $component . '\\output\\renderer'
-            );
+                'classname' => '\\' . $component . '\\output\\renderer',
+            ];
             // Legacy class name - (valid with or without a prefix).
-            $classnames[] = array(
+            $classnames[] = [
                 'validwithprefix' => true,
                 'validwithoutprefix' => true,
                 'autoloaded' => false,
-                'classname' => $component . '_renderer'
-            );
+                'classname' => $component . '_renderer',
+            ];
         } else {
             // Theme specific auto-loaded name (only valid when prefixed with the theme name).
-            $classnames[] = array(
+            $classnames[] = [
                 'validwithprefix' => true,
                 'validwithoutprefix' => false,
                 'autoloaded' => true,
-                'classname' => '\\output\\' . $component . '\\' . $subtype . '_renderer'
-            );
+                'classname' => '\\output\\' . $component . '\\' . $subtype . '_renderer',
+            ];
             // Version of the above with subtype being a namespace level on it's own.
-            $classnames[] = array(
+            $classnames[] = [
                 'validwithprefix' => true,
                 'validwithoutprefix' => false,
                 'autoloaded' => true,
-                'classname' => '\\output\\' . $component . '\\' . $subtype . '\\renderer'
-            );
+                'classname' => '\\output\\' . $component . '\\' . $subtype . '\\renderer',
+            ];
             // Standard autoloaded plugin name (not valid with a prefix).
-            $classnames[] = array(
+            $classnames[] = [
                 'validwithprefix' => false,
                 'validwithoutprefix' => true,
                 'autoloaded' => true,
-                'classname' => '\\' . $component . '\\output\\' . $subtype . '_renderer'
-            );
+                'classname' => '\\' . $component . '\\output\\' . $subtype . '_renderer',
+            ];
             // Version of the above with subtype being a namespace level on it's own.
-            $classnames[] = array(
+            $classnames[] = [
                 'validwithprefix' => false,
                 'validwithoutprefix' => true,
                 'autoloaded' => true,
-                'classname' => '\\' . $component . '\\output\\' . $subtype . '\\renderer'
-            );
+                'classname' => '\\' . $component . '\\output\\' . $subtype . '\\renderer',
+            ];
             // Legacy class name - (valid with or without a prefix).
-            $classnames[] = array(
+            $classnames[] = [
                 'validwithprefix' => true,
                 'validwithoutprefix' => true,
                 'autoloaded' => false,
-                'classname' => $component . '_' . $subtype . '_renderer'
-            );
+                'classname' => $component . '_' . $subtype . '_renderer',
+            ];
         }
         return $classnames;
     }
diff --git a/lib/classes/output/renderer_factory/renderer_factory_interface.php b/lib/classes/output/renderer_factory/renderer_factory_interface.php
index 9707182c517..792e5be1487 100644
--- a/lib/classes/output/renderer_factory/renderer_factory_interface.php
+++ b/lib/classes/output/renderer_factory/renderer_factory_interface.php
@@ -27,7 +27,7 @@ use core\output\renderer_base;
  * if created automatically when the theme is set up.
  *
  * A renderer factory must also have a constructor that takes a theme_config object.
- * (See {@link renderer_factory_base::__construct} for an example.)
+ * (See {@see renderer_factory_base::__construct} for an example.)
  *
  * @copyright 2009 Tim Hunt
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
@@ -61,7 +61,7 @@ interface renderer_factory_interface {
      * @param string $target one of rendering target constants
      * @return renderer_base an object implementing the requested renderer interface.
      */
-    public function get_renderer(moodle_page $page, $component, $subtype=null, $target=null);
+    public function get_renderer(moodle_page $page, $component, $subtype = null, $target = null);
 }
 
 // Alias this class to the old name.
diff --git a/lib/classes/output/renderer_factory/standard_renderer_factory.php b/lib/classes/output/renderer_factory/standard_renderer_factory.php
index ac2651d992a..d3201ef2c0f 100644
--- a/lib/classes/output/renderer_factory/standard_renderer_factory.php
+++ b/lib/classes/output/renderer_factory/standard_renderer_factory.php
@@ -45,7 +45,7 @@ class standard_renderer_factory extends renderer_factory_base {
         $classnames = $this->standard_renderer_classnames($component, $subtype);
         $classname = '';
 
-        list($target, $suffix) = $this->get_target_suffix($target);
+        [$target, $suffix] = $this->get_target_suffix($target);
         // First look for a version with a suffix.
         foreach ($classnames as $classnamedetails) {
             if ($classnamedetails['validwithoutprefix']) {
diff --git a/lib/classes/output/renderer_factory/theme_overridden_renderer_factory.php b/lib/classes/output/renderer_factory/theme_overridden_renderer_factory.php
index 3e7cc10bfac..04d41c5b146 100644
--- a/lib/classes/output/renderer_factory/theme_overridden_renderer_factory.php
+++ b/lib/classes/output/renderer_factory/theme_overridden_renderer_factory.php
@@ -40,7 +40,7 @@ class theme_overridden_renderer_factory extends renderer_factory_base {
     /**
      * @var array An array of renderer prefixes
      */
-    protected $prefixes = array();
+    protected $prefixes = [];
 
     /**
      * Constructor.
@@ -64,7 +64,7 @@ class theme_overridden_renderer_factory extends renderer_factory_base {
     public function get_renderer(moodle_page $page, $component, $subtype = null, $target = null) {
         $classnames = $this->standard_renderer_classnames($component, $subtype);
 
-        list($target, $suffix) = $this->get_target_suffix($target);
+        [$target, $suffix] = $this->get_target_suffix($target);
 
         // Theme lib.php and renderers.php files are loaded automatically
         // when loading the theme configs.
diff --git a/lib/classes/output/requirements/fragment_requirements_manager.php b/lib/classes/output/requirements/fragment_requirements_manager.php
index 9a71fe77f59..5240c34ca49 100644
--- a/lib/classes/output/requirements/fragment_requirements_manager.php
+++ b/lib/classes/output/requirements/fragment_requirements_manager.php
@@ -30,7 +30,6 @@ use js_writer;
  * @category output
  */
 class fragment_requirements_manager extends page_requirements_manager {
-
     /**
      * Page fragment constructor.
      */
@@ -84,7 +83,7 @@ class fragment_requirements_manager extends page_requirements_manager {
 
         if (!empty($this->stringsforjs)) {
             // Add all needed strings.
-            $strings = array();
+            $strings = [];
             foreach ($this->stringsforjs as $component => $v) {
                 foreach ($v as $indentifier => $langstring) {
                     $strings[$component][$indentifier] = $langstring->out();
@@ -100,7 +99,7 @@ class fragment_requirements_manager extends page_requirements_manager {
         if ($this->jsinitvariables['footer']) {
             $js = '';
             foreach ($this->jsinitvariables['footer'] as $data) {
-                list($var, $value) = $data;
+                [$var, $value] = $data;
                 $js .= js_writer::set_variable($var, $value, true);
             }
             $output .= html_writer::script($js);
diff --git a/lib/classes/output/requirements/page_requirements_manager.php b/lib/classes/output/requirements/page_requirements_manager.php
index f19999b558e..a417d4e9ac6 100644
--- a/lib/classes/output/requirements/page_requirements_manager.php
+++ b/lib/classes/output/requirements/page_requirements_manager.php
@@ -48,7 +48,7 @@ use stdClass;
  *     $PAGE->requires->js_function_call('init_mymod', array($data), true);
  * </pre>
  *
- * There are some natural restrictions on some methods. For example, {@link css()}
+ * There are some natural restrictions on some methods. For example, {@see css()}
  * can only be called before the <head> tag is output. See the comments on the
  * individual methods for details.
  *
@@ -62,71 +62,71 @@ class page_requirements_manager {
     /**
      * @var array List of string available from JS
      */
-    protected $stringsforjs = array();
+    protected $stringsforjs = [];
 
     /**
      * @var array List of get_string $a parameters - used for validation only.
      */
-    protected $stringsforjs_as = array();
+    protected $stringsforjs_as = []; // phpcs:ignore moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
 
     /**
      * @var array List of JS variables to be initialised
      */
-    protected $jsinitvariables = array('head'=>array(), 'footer'=>array());
+    protected $jsinitvariables = ['head' => [], 'footer' => []];
 
     /**
      * @var array Included JS scripts
      */
-    protected $jsincludes = array('head'=>array(), 'footer'=>array());
+    protected $jsincludes = ['head' => [], 'footer' => []];
 
     /**
      * @var array Inline scripts using RequireJS module loading.
      */
-    protected $amdjscode = array('');
+    protected $amdjscode = [''];
 
     /**
      * @var array List of needed function calls
      */
-    protected $jscalls = array('normal'=>array(), 'ondomready'=>array());
+    protected $jscalls = ['normal' => [], 'ondomready' => []];
 
     /**
      * @var array List of skip links, those are needed for accessibility reasons
      */
-    protected $skiplinks = array();
+    protected $skiplinks = [];
 
     /**
      * @var array Javascript code used for initialisation of page, it should
      * be relatively small
      */
-    protected $jsinitcode = array();
+    protected $jsinitcode = [];
 
     /**
      * @var array of moodle_url Theme sheets, initialised only from core_renderer
      */
-    protected $cssthemeurls = array();
+    protected $cssthemeurls = [];
 
     /**
      * @var array of moodle_url List of custom theme sheets, these are strongly discouraged!
      * Useful mostly only for CSS submitted by teachers that is not part of the theme.
      */
-    protected $cssurls = array();
+    protected $cssurls = [];
 
     /**
      * @var array List of requested event handlers
      */
-    protected $eventhandlers = array();
+    protected $eventhandlers = [];
 
     /**
      * @var array Extra modules
      */
-    protected $extramodules = array();
+    protected $extramodules = [];
 
     /**
      * @var array trackes the names of bits of HTML that are only required once
-     * per page. See {@link has_one_time_item_been_created()},
-     * {@link set_one_time_item_created()} and {@link should_create_one_time_item_now()}.
+     * per page. See {@see has_one_time_item_been_created()},
+     * {@see set_one_time_item_created()} and {@see should_create_one_time_item_now()}.
      */
-    protected $onetimeitemsoutput = array();
+    protected $onetimeitemsoutput = [];
 
     /**
      * @var bool Flag indicated head stuff already printed
@@ -146,27 +146,27 @@ class page_requirements_manager {
     /**
      * @var yui default YUI loader configuration
      */
-    protected $YUI_config;
+    protected $YUI_config; // phpcs:ignore moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
 
     /**
      * @var array $yuicssmodules
      */
-    protected $yuicssmodules = array();
+    protected $yuicssmodules = [];
 
     /**
      * @var array Some config vars exposed in JS, please no secret stuff there
      */
-    protected $M_cfg;
+    protected $M_cfg; // phpcs:ignore moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
 
     /**
      * @var array list of requested jQuery plugins
      */
-    protected $jqueryplugins = array();
+    protected $jqueryplugins = [];
 
     /**
      * @var array list of jQuery plugin overrides
      */
-    protected $jquerypluginoverrides = array();
+    protected $jquerypluginoverrides = [];
 
     /**
      * Page requirements constructor.
@@ -181,8 +181,8 @@ class page_requirements_manager {
         $this->YUI_config = new yui();
 
         // Set up some loader options.
-        $this->yui3loader->local_base = $CFG->wwwroot . '/lib/yuilib/'. $CFG->yui3version . '/';
-        $this->yui3loader->local_comboBase = $CFG->wwwroot . '/theme/yui_combo.php'.$sep;
+        $this->yui3loader->local_base = $CFG->wwwroot . '/lib/yuilib/' . $CFG->yui3version . '/';
+        $this->yui3loader->local_comboBase = $CFG->wwwroot . '/theme/yui_combo.php' . $sep;
 
         $this->yui3loader->base = $this->yui3loader->local_base;
         $this->yui3loader->comboBase = $this->yui3loader->local_comboBase;
@@ -199,56 +199,58 @@ class page_requirements_manager {
 
         // If we've had to patch any YUI modules between releases, we must override the YUI configuration to include them.
         if (!empty($CFG->yuipatchedmodules) && !empty($CFG->yuipatchlevel)) {
-            $this->YUI_config->define_patched_core_modules($this->yui3loader->local_comboBase,
-                    $CFG->yui3version,
-                    $CFG->yuipatchlevel,
-                    $CFG->yuipatchedmodules);
+            $this->YUI_config->define_patched_core_modules(
+                $this->yui3loader->local_comboBase,
+                $CFG->yui3version,
+                $CFG->yuipatchlevel,
+                $CFG->yuipatchedmodules
+            );
         }
 
         $configname = $this->YUI_config->set_config_source('lib/yui/config/yui2.js');
-        $this->YUI_config->add_group('yui2', array(
+        $this->YUI_config->add_group('yui2', [
             // Loader configuration for our 2in3.
             'base' => $CFG->wwwroot . '/lib/yuilib/2in3/' . $CFG->yui2version . '/build/',
-            'comboBase' => $CFG->wwwroot . '/theme/yui_combo.php'.$sep,
+            'comboBase' => $CFG->wwwroot . '/theme/yui_combo.php' . $sep,
             'combine' => $this->yui3loader->combine,
             'ext' => false,
-            'root' => '2in3/' . $CFG->yui2version .'/build/',
-            'patterns' => array(
-                'yui2-' => array(
+            'root' => '2in3/' . $CFG->yui2version . '/build/',
+            'patterns' => [
+                'yui2-' => [
                     'group' => 'yui2',
                     'configFn' => $configname,
-                )
-            )
-        ));
+                ],
+            ],
+        ]);
         $configname = $this->YUI_config->set_config_source('lib/yui/config/moodle.js');
-        $this->YUI_config->add_group('moodle', array(
+        $this->YUI_config->add_group('moodle', [
             'name' => 'moodle',
             'base' => $CFG->wwwroot . '/theme/yui_combo.php' . $sep . 'm/' . $jsrev . '/',
             'combine' => $this->yui3loader->combine,
-            'comboBase' => $CFG->wwwroot . '/theme/yui_combo.php'.$sep,
+            'comboBase' => $CFG->wwwroot . '/theme/yui_combo.php' . $sep,
             'ext' => false,
-            'root' => 'm/'.$jsrev.'/', // Add the rev to the root path so that we can control caching.
-            'patterns' => array(
-                'moodle-' => array(
+            'root' => 'm/' . $jsrev . '/', // Add the rev to the root path so that we can control caching.
+            'patterns' => [
+                'moodle-' => [
                     'group' => 'moodle',
                     'configFn' => $configname,
-                )
-            )
-        ));
+                ],
+            ],
+        ]);
 
-        $this->YUI_config->add_group('gallery', array(
+        $this->YUI_config->add_group('gallery', [
             'name' => 'gallery',
             'base' => $CFG->wwwroot . '/lib/yuilib/gallery/',
             'combine' => $this->yui3loader->combine,
             'comboBase' => $CFG->wwwroot . '/theme/yui_combo.php' . $sep,
             'ext' => false,
             'root' => 'gallery/' . $jsrev . '/',
-            'patterns' => array(
-                'gallery-' => array(
+            'patterns' => [
+                'gallery-' => [
                     'group' => 'gallery',
-                )
-            )
-        ));
+                ],
+            ],
+        ]);
 
         // Set some more loader options applying to groups too.
         if ($CFG->debugdeveloper) {
@@ -291,13 +293,14 @@ class page_requirements_manager {
      * Return the safe config values that get set for javascript in "M.cfg".
      *
      * @since 2.9
+     * @param moodle_page $page The page to add JS to
+     * @param renderer_base $renderer The renderer to use
      * @return array List of safe config values that are available to javascript.
      */
     public function get_config_for_javascript(moodle_page $page, renderer_base $renderer) {
         global $CFG;
 
         if (empty($this->M_cfg)) {
-
             $iconsystem = \core\output\icon_system::instance();
 
             // It is possible that the $page->context is null, so we can't use $page->context->id.
@@ -310,7 +313,7 @@ class page_requirements_manager {
                 $coursecontext = context_course::instance($courseid);
             }
 
-            $this->M_cfg = array(
+            $this->M_cfg = [
                 'wwwroot'               => $CFG->wwwroot,
                 'homeurl'               => $page->navigation->action,
                 'sesskey'               => sesskey(),
@@ -332,14 +335,13 @@ class page_requirements_manager {
                 'langrev'               => get_string_manager()->get_revision(),
                 'templaterev'           => $this->get_templaterev(),
                 'siteId'                => (int) SITEID,
-            );
+            ];
             if ($CFG->debugdeveloper) {
                 $this->M_cfg['developerdebug'] = true;
             }
             if (defined('BEHAT_SITE_RUNNING')) {
                 $this->M_cfg['behatsiterunning'] = true;
             }
-
         }
         return $this->M_cfg;
     }
@@ -369,21 +371,25 @@ class page_requirements_manager {
             $this->js_init_call('M.util.init_frametop');
         }
 
-        // Include block drag/drop if editing is on
+        // Include block drag/drop if editing is on.
         if ($page->user_is_editing()) {
-            $params = array(
+            $params = [
                 'regions' => $page->blocks->get_regions(),
                 'pagehash' => $page->get_edited_page_hash(),
-            );
+            ];
             if (!empty($page->cm->id)) {
                 $params['cmid'] = $page->cm->id;
             }
             // Strings for drag and drop.
-            $this->strings_for_js(array('movecontent',
-                                        'tocontent',
-                                        'emptydragdropregion'),
-                                  'moodle');
-            $page->requires->yui_module('moodle-core-blocks', 'M.core_blocks.init_dragdrop', array($params), null, true);
+            $this->strings_for_js(
+                [
+                    'movecontent',
+                    'tocontent',
+                    'emptydragdropregion',
+                ],
+                'moodle',
+            );
+            $page->requires->yui_module('moodle-core-blocks', 'M.core_blocks.init_dragdrop', [$params], null, true);
             $page->requires->js_call_amd('core_block/edit', 'init', ['pagehash' => $page->get_edited_page_hash()]);
         }
 
@@ -459,7 +465,7 @@ class page_requirements_manager {
      *
      * NOTE: this should not be used in official Moodle distribution!
      *
-     * {@link https://moodledev.io/docs/guides/javascript/jquery}
+     * @link https://moodledev.io/docs/guides/javascript/jquery
      */
     public function jquery() {
         $this->jquery_plugin('jquery');
@@ -521,15 +527,18 @@ class page_requirements_manager {
             return false;
         }
 
-        if ($component !== 'core' and in_array($plugin, array('jquery', 'ui', 'ui-css'))) {
-            debugging("jQuery plugin '$plugin' is included in Moodle core, other components can not use the same name.", DEBUG_DEVELOPER);
+        if ($component !== 'core' && in_array($plugin, ['jquery', 'ui', 'ui-css'])) {
+            debugging(
+                "jQuery plugin '$plugin' is included in Moodle core, other components can not use the same name.",
+                DEBUG_DEVELOPER,
+            );
             $component = 'core';
-        } else if ($component !== 'core' and strpos($component, '_') === false) {
+        } else if ($component !== 'core' && strpos($component, '_') === false) {
             // Let's normalise the legacy activity names, Frankenstyle rulez!
             $component = 'mod_' . $component;
         }
 
-        if (empty($this->jqueryplugins) and ($component !== 'core' or $plugin !== 'jquery')) {
+        if (empty($this->jqueryplugins) && ($component !== 'core' || $plugin !== 'jquery')) {
             // Make sure the jQuery itself is always loaded first,
             // the order of all other plugins depends on order of $PAGE_>requires->.
             $this->jquery_plugin('jquery', 'core');
@@ -541,12 +550,12 @@ class page_requirements_manager {
         }
 
         $componentdir = core_component::get_component_directory($component);
-        if (!file_exists($componentdir) or !file_exists("$componentdir/jquery/plugins.php")) {
+        if (!file_exists($componentdir) || !file_exists("$componentdir/jquery/plugins.php")) {
             debugging("Can not load jQuery plugin '$plugin', missing plugins.php in component '$component'.", DEBUG_DEVELOPER);
             return false;
         }
 
-        $plugins = array();
+        $plugins = [];
         require("$componentdir/jquery/plugins.php");
 
         if (!isset($plugins[$plugin])) {
@@ -557,7 +566,7 @@ class page_requirements_manager {
         $this->jqueryplugins[$plugin] = new stdClass();
         $this->jqueryplugins[$plugin]->plugin    = $plugin;
         $this->jqueryplugins[$plugin]->component = $component;
-        $this->jqueryplugins[$plugin]->urls      = array();
+        $this->jqueryplugins[$plugin]->urls      = [];
 
         foreach ($plugins[$plugin]['files'] as $file) {
             if ($CFG->debugdeveloper) {
@@ -575,12 +584,11 @@ class page_requirements_manager {
             if (!empty($CFG->slasharguments)) {
                 $url = new moodle_url("/theme/jquery.php");
                 $url->set_slashargument("/$component/$file");
-
             } else {
                 // This is not really good, we need slasharguments for relative links, this means no caching...
                 $path = realpath("$componentdir/jquery/$file");
                 if (strpos($path, $CFG->dirroot) === 0) {
-                    $url = $CFG->wwwroot.preg_replace('/^'.preg_quote($CFG->dirroot, '/').'/', '', $path);
+                    $url = $CFG->wwwroot . preg_replace('/^' . preg_quote($CFG->dirroot, '/') . '/', '', $path);
                     // Replace all occurences of backslashes characters in url to forward slashes.
                     $url = str_replace('\\', '/', $url);
                     $url = new moodle_url($url);
@@ -618,7 +626,7 @@ class page_requirements_manager {
      * This code prevents loading of standard 'ui-css' which my be requested by other plugins,
      * the 'yourtheme-ui-css' gets loaded only if some other code requires jquery.
      *
-     * {@link https://moodledev.io/docs/guides/javascript/jquery}
+     * @link https://moodledev.io/docs/guides/javascript/jquery
      *
      * @param string $oldplugin original plugin
      * @param string $newplugin the replacement
@@ -642,8 +650,8 @@ class page_requirements_manager {
             return '';
         }
 
-        $included = array();
-        $urls = array();
+        $included = [];
+        $urls = [];
 
         foreach ($this->jqueryplugins as $name => $unused) {
             if (isset($included[$name])) {
@@ -655,7 +663,7 @@ class page_requirements_manager {
                 // in blank page.
                 $cyclic = true;
                 $oldname = $name;
-                for ($i=0; $i<100; $i++) {
+                for ($i = 0; $i < 100; $i++) {
                     $name = $this->jquerypluginoverrides[$name];
                     if (!array_key_exists($name, $this->jquerypluginoverrides)) {
                         $cyclic = false;
@@ -666,15 +674,12 @@ class page_requirements_manager {
                     // We can not do much with cyclic references here, let's use the old plugin.
                     $name = $oldname;
                     debugging("Cyclic overrides detected for jQuery plugin '$name'");
-
                 } else if (empty($name)) {
                     // Developer requested removal of the plugin.
                     continue;
-
                 } else if (!isset($this->jqueryplugins[$name])) {
                     debugging("Unknown jQuery override plugin '$name' detected");
                     $name = $oldname;
-
                 } else if (isset($included[$name])) {
                     // The plugin was already included, easy.
                     continue;
@@ -687,7 +692,7 @@ class page_requirements_manager {
         }
 
         $output = '';
-        $attributes = array('rel' => 'stylesheet', 'type' => 'text/css');
+        $attributes = ['rel' => 'stylesheet', 'type' => 'text/css'];
         foreach ($urls as $url) {
             if (preg_match('/\.js$/', $url)) {
                 $output .= html_writer::script('', $url);
@@ -743,7 +748,7 @@ class page_requirements_manager {
                     return new moodle_url('/lib/javascript.php', ['rev' => $jsrev, 'jsfile' => $url]);
                 } else {
                     $returnurl = new moodle_url('/lib/javascript.php');
-                    $returnurl->set_slashargument('/'.$jsrev.$url);
+                    $returnurl->set_slashargument('/' . $jsrev . $url);
                     return $returnurl;
                 }
             } else {
@@ -768,77 +773,104 @@ class page_requirements_manager {
         if (strpos($component, 'core_') === 0) {
             // Must be some core stuff - list here is not complete, this is just the stuff used from multiple places
             // so that we do nto have to repeat the definition of these modules over and over again.
-            switch($component) {
+            switch ($component) {
                 case 'core_filepicker':
-                    $module = array('name'     => 'core_filepicker',
-                                    'fullpath' => '/repository/filepicker.js',
-                                    'requires' => array(
-                                        'base', 'node', 'node-event-simulate', 'json', 'async-queue', 'io-base', 'io-upload-iframe', 'io-form',
-                                        'yui2-treeview', 'panel', 'cookie', 'datatable', 'datatable-sort', 'resize-plugin', 'dd-plugin',
-                                        'escape', 'moodle-core_filepicker', 'moodle-core-notification-dialogue'
-                                    ),
-                                    'strings'  => array(array('lastmodified', 'moodle'), array('name', 'moodle'), array('type', 'repository'), array('size', 'repository'),
-                                                        array('invalidjson', 'repository'), array('error', 'moodle'), array('info', 'moodle'),
-                                                        array('nofilesattached', 'repository'), array('filepicker', 'repository'), array('logout', 'repository'),
-                                                        array('nofilesavailable', 'repository'), array('norepositoriesavailable', 'repository'),
-                                                        array('fileexistsdialogheader', 'repository'), array('fileexistsdialog_editor', 'repository'),
-                                                        array('fileexistsdialog_filemanager', 'repository'), array('renameto', 'repository'),
-                                                        array('referencesexist', 'repository'), array('select', 'repository')
-                                                    ));
+                    $module = [
+                        'name' => 'core_filepicker',
+                        'fullpath' => '/repository/filepicker.js',
+                        'requires' => [
+                            'base', 'node', 'node-event-simulate', 'json', 'async-queue', 'io-base', 'io-upload-iframe', 'io-form',
+                            'yui2-treeview', 'panel', 'cookie', 'datatable', 'datatable-sort', 'resize-plugin', 'dd-plugin',
+                            'escape', 'moodle-core_filepicker', 'moodle-core-notification-dialogue',
+                        ],
+                        'strings'  => [
+                            ['lastmodified', 'moodle'],
+                            ['name', 'moodle'],
+                            ['type', 'repository'],
+                            ['size', 'repository'],
+                            ['invalidjson', 'repository'],
+                            ['error', 'moodle'],
+                            ['info', 'moodle'],
+                            ['nofilesattached', 'repository'],
+                            ['filepicker', 'repository'],
+                            ['logout', 'repository'],
+                            ['nofilesavailable', 'repository'],
+                            ['norepositoriesavailable', 'repository'],
+                            ['fileexistsdialogheader', 'repository'],
+                            ['fileexistsdialog_editor', 'repository'],
+                            ['fileexistsdialog_filemanager', 'repository'],
+                            ['renameto', 'repository'],
+                            ['referencesexist', 'repository'],
+                            ['select', 'repository'],
+                        ],
+                    ];
                     break;
                 case 'core_comment':
-                    $module = array('name'     => 'core_comment',
-                                    'fullpath' => '/comment/comment.js',
-                                    'requires' => array('base', 'io-base', 'node', 'json', 'yui2-animation', 'overlay', 'escape'),
-                                    'strings' => array(array('confirmdeletecomments', 'admin'), array('yes', 'moodle'), array('no', 'moodle'))
-                                );
+                    $module = [
+                        'name' => 'core_comment',
+                        'fullpath' => '/comment/comment.js',
+                        'requires' => ['base', 'io-base', 'node', 'json', 'yui2-animation', 'overlay', 'escape'],
+                        'strings' => [['confirmdeletecomments', 'admin'], ['yes', 'moodle'], ['no', 'moodle']],
+                    ];
                     break;
                 case 'core_role':
-                    $module = array('name'     => 'core_role',
-                                    'fullpath' => '/admin/roles/module.js',
-                                    'requires' => array('node', 'cookie'));
+                    $module = [
+                        'name' => 'core_role',
+                        'fullpath' => '/admin/roles/module.js',
+                        'requires' => ['node', 'cookie'],
+                    ];
                     break;
                 case 'core_completion':
                     break;
                 case 'core_message':
-                    $module = array('name'     => 'core_message',
-                                    'requires' => array('base', 'node', 'event', 'node-event-simulate'),
-                                    'fullpath' => '/message/module.js');
+                    $module = [
+                        'name' => 'core_message',
+                        'requires' => ['base', 'node', 'event', 'node-event-simulate'],
+                        'fullpath' => '/message/module.js',
+                    ];
                     break;
                 case 'core_group':
-                    $module = array('name'     => 'core_group',
-                                    'fullpath' => '/group/module.js',
-                                    'requires' => array('node', 'overlay', 'event-mouseenter'));
+                    $module = [
+                        'name' => 'core_group',
+                        'fullpath' => '/group/module.js',
+                        'requires' => ['node', 'overlay', 'event-mouseenter'],
+                    ];
                     break;
                 case 'core_question_engine':
-                    $module = array('name'     => 'core_question_engine',
-                                    'fullpath' => '/question/qengine.js',
-                                    'requires' => array('node', 'event'));
+                    $module = [
+                        'name' => 'core_question_engine',
+                        'fullpath' => '/question/qengine.js',
+                        'requires' => ['node', 'event'],
+                    ];
                     break;
                 case 'core_rating':
-                    $module = array('name'     => 'core_rating',
-                                    'fullpath' => '/rating/module.js',
-                                    'requires' => array('node', 'event', 'overlay', 'io-base', 'json'));
+                    $module = [
+                        'name' => 'core_rating',
+                        'fullpath' => '/rating/module.js',
+                        'requires' => ['node', 'event', 'overlay', 'io-base', 'json'],
+                    ];
                     break;
                 case 'core_dndupload':
-                    $module = array('name'     => 'core_dndupload',
-                                    'fullpath' => '/lib/form/dndupload.js',
-                                    'requires' => array('node', 'event', 'json', 'core_filepicker'),
-                                    'strings'  => array(array('uploadformlimit', 'moodle'), array('droptoupload', 'moodle'), array('maxfilesreached', 'moodle'),
-                                                        array('dndenabled_inbox', 'moodle'), array('fileexists', 'moodle'), array('maxbytesfile', 'error'),
-                                                        array('sizegb', 'moodle'), array('sizemb', 'moodle'), array('sizekb', 'moodle'), array('sizeb', 'moodle'),
-                                                        array('maxareabytesreached', 'moodle'), array('serverconnection', 'error'),
-                                                        array('changesmadereallygoaway', 'moodle'), array('complete', 'moodle')
-                                                    ));
+                    $module = [
+                        'name' => 'core_dndupload',
+                        'fullpath' => '/lib/form/dndupload.js',
+                        'requires' => ['node', 'event', 'json', 'core_filepicker'],
+                        'strings'  => [
+                            ['uploadformlimit', 'moodle'], ['droptoupload', 'moodle'], ['maxfilesreached', 'moodle'],
+                            ['dndenabled_inbox', 'moodle'], ['fileexists', 'moodle'], ['maxbytesfile', 'error'],
+                            ['sizegb', 'moodle'], ['sizemb', 'moodle'], ['sizekb', 'moodle'], ['sizeb', 'moodle'],
+                            ['maxareabytesreached', 'moodle'], ['serverconnection', 'error'],
+                            ['changesmadereallygoaway', 'moodle'], ['complete', 'moodle'],
+                        ],
+                    ];
                     break;
             }
-
         } else {
             if ($dir = core_component::get_component_directory($component)) {
                 if (file_exists("$dir/module.js")) {
-                    if (strpos($dir, $CFG->dirroot.'/') === 0) {
+                    if (strpos($dir, $CFG->dirroot . '/') === 0) {
                         $dir = substr($dir, strlen($CFG->dirroot));
-                        $module = array('name'=>$component, 'fullpath'=>"$dir/module.js", 'requires' => array());
+                        $module = ['name' => $component, 'fullpath' => "$dir/module.js", 'requires' => []];
                     }
                 }
             }
@@ -865,7 +897,7 @@ class page_requirements_manager {
             $module = $this->find_module($module);
         }
 
-        if (empty($module) or empty($module['name']) or empty($module['fullpath'])) {
+        if (empty($module) || empty($module['name']) || empty($module['fullpath'])) {
             throw new coding_exception('Missing YUI3 module details.');
         }
 
@@ -883,7 +915,7 @@ class page_requirements_manager {
 
         // Process module requirements and attempt to load each. This allows
         // moodle modules to require each other.
-        if (!empty($module['requires'])){
+        if (!empty($module['requires'])) {
             foreach ($module['requires'] as $requirement) {
                 $rmodule = $this->find_module($requirement);
                 if (is_array($rmodule)) {
@@ -919,7 +951,7 @@ class page_requirements_manager {
      * Ensure that the specified CSS file is linked to from this page.
      *
      * Because stylesheet links must go in the <head> part of the HTML, you must call
-     * this function before {@link get_head_code()} is called. That normally means before
+     * this function before {@see get_head_code()} is called. That normally means before
      * the call to print_header. If you call it when it is too late, an exception
      * will be thrown.
      *
@@ -942,8 +974,9 @@ class page_requirements_manager {
             throw new coding_exception('Cannot require a CSS file after &lt;head> has been printed.', $stylesheet);
         }
 
+        // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedIf
         if ($stylesheet instanceof moodle_url) {
-            // ok
+            // Ok.
         } else if (strpos($stylesheet, '/') === 0) {
             $stylesheet = new moodle_url($stylesheet);
         } else {
@@ -967,7 +1000,7 @@ class page_requirements_manager {
     /**
      * Ensure that a skip link to a given target is printed at the top of the <body>.
      *
-     * You must call this function before {@link get_top_of_body_code()}, (if not, an exception
+     * You must call this function before {@see get_top_of_body_code()}, (if not, an exception
      * will be thrown). That normally means you must call this before the call to print_header.
      *
      * If you ask for a particular skip link to be printed, it is then your responsibility
@@ -1007,16 +1040,21 @@ class page_requirements_manager {
      * @param string $function the name of the JavaScritp function to call. Can
      *      be a compound name like 'Y.Event.purgeElement'. Can also be
      *      used to create and object by using a 'function name' like 'new user_selector'.
-     * @param array $arguments and array of arguments to be passed to the function.
+     * @param null|array $arguments and array of arguments to be passed to the function.
      *      When generating the function call, this will be escaped using json_encode,
      *      so passing objects and arrays should work.
      * @param bool $ondomready If tru the function is only called when the dom is
      *      ready for manipulation.
      * @param int $delay The delay before the function is called.
      */
-    public function js_function_call($function, array $arguments = null, $ondomready = false, $delay = 0) {
+    public function js_function_call(
+        $function,
+        ?array $arguments = null,
+        $ondomready = false,
+        $delay = 0,
+    ) {
         $where = $ondomready ? 'ondomready' : 'normal';
-        $this->jscalls[$where][] = array($function, $arguments, $delay);
+        $this->jscalls[$where][] = [$function, $arguments, $delay];
     }
 
     /**
@@ -1042,7 +1080,7 @@ class page_requirements_manager {
      * @param string $func Optional function from the module to call, defaults to just loading the AMD module.
      * @param array $params The params to pass to the function (will be serialized into JSON).
      */
-    public function js_call_amd($fullmodule, $func = null, $params = array()) {
+    public function js_call_amd($fullmodule, $func = null, $params = []) {
         global $CFG;
 
         $modulepath = explode('/', $fullmodule);
@@ -1056,7 +1094,7 @@ class page_requirements_manager {
         if ($func !== null) {
             $func = clean_param($func, PARAM_ALPHANUMEXT);
 
-            $jsonparams = array();
+            $jsonparams = [];
             foreach ($params as $param) {
                 $jsonparams[] = json_encode($param);
             }
@@ -1096,20 +1134,34 @@ class page_requirements_manager {
      *
      * @param array|string $modules One or more modules
      * @param string $function The function to call once modules have been loaded
-     * @param array $arguments An array of arguments to pass to the function
-     * @param string $galleryversion Deprecated: The gallery version to use
+     * @param null|array $arguments An array of arguments to pass to the function
+     * @param null|string $galleryversion Deprecated: The gallery version to use
      * @param bool $ondomready
      */
-    public function yui_module($modules, $function, array $arguments = null, $galleryversion = null, $ondomready = false) {
+    public function yui_module(
+        $modules,
+        $function,
+        ?array $arguments = null,
+        $galleryversion = null,
+        $ondomready = false,
+    ) {
         if (!is_array($modules)) {
-            $modules = array($modules);
+            $modules = [$modules];
         }
 
         if ($galleryversion != null) {
             debugging('The galleryversion parameter to yui_module has been deprecated since Moodle 2.3.');
         }
 
-        $jscode = 'Y.use('.join(',', array_map('json_encode', convert_to_array($modules))).',function() {'.js_writer::function_call($function, $arguments).'});';
+        $jscode = 'Y.use(' .
+            join(
+                ',',
+                array_map(
+                    'json_encode',
+                    convert_to_array($modules)
+                )
+            ) .
+            ',function() {' . js_writer::function_call($function, $arguments) . '});';
         if ($ondomready) {
             $jscode = "Y.on('domready', function() { $jscode });";
         }
@@ -1121,7 +1173,7 @@ class page_requirements_manager {
      *
      * @param array $modules The list of YUI CSS Modules to include.
      */
-    public function set_yuicssmodules(array $modules = array()) {
+    public function set_yuicssmodules(array $modules = []) {
         $this->yuicssmodules = $modules;
     }
 
@@ -1131,13 +1183,18 @@ class page_requirements_manager {
      *
      * @param string $function the name of the JavaScritp function to with init code,
      *      usually something like 'M.mod_mymodule.init'
-     * @param array $extraarguments and array of arguments to be passed to the function.
+     * @param null|array $extraarguments and array of arguments to be passed to the function.
      *      The first argument is always the YUI3 Y instance with all required dependencies
      *      already loaded.
      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
-     * @param array $module JS module specification array
+     * @param null|array $module JS module specification array
      */
-    public function js_init_call($function, array $extraarguments = null, $ondomready = false, array $module = null) {
+    public function js_init_call(
+        $function,
+        ?array $extraarguments = null,
+        $ondomready = false,
+        ?array $module = null,
+    ) {
         $jscode = js_writer::function_call_with_Y($function, $extraarguments);
         if (!$module) {
             // Detect module automatically.
@@ -1157,10 +1214,14 @@ class page_requirements_manager {
      *
      * @param string $jscode
      * @param bool $ondomready wait for dom ready (helps with some IE problems when modifying DOM)
-     * @param array $module JS module specification array
+     * @param null|array $module JS module specification array
      */
-    public function js_init_code($jscode, $ondomready = false, array $module = null) {
-        $jscode = trim($jscode, " ;\n"). ';';
+    public function js_init_code(
+        $jscode,
+        $ondomready = false,
+        ?array $module = null,
+    ) {
+        $jscode = trim($jscode, " ;\n") . ';';
 
         $uniqid = html_writer::random_id();
         $startjs = " M.util.js_pending('" . $uniqid . "');";
@@ -1212,7 +1273,7 @@ class page_requirements_manager {
      *     alert(M.str.moodle.fullnamedisplay);
      *
      * To substitute the placeholder at client side, use M.util.get_string()
-     * function. It implements the same logic as {@link get_string()}:
+     * function. It implements the same logic as {@see get_string()}:
      *
      *     // Require the string in PHP but keep {$a} as it is.
      *     $PAGE->requires->string_for_js('fullnamedisplay', 'moodle');
@@ -1222,7 +1283,7 @@ class page_requirements_manager {
      *
      * If you do need the same string expanded with different $a values in PHP
      * on server side, then the solution is to put them in your own data structure
-     * (e.g. and array) that you pass to JavaScript with {@link data_for_js()}.
+     * (e.g. and array) that you pass to JavaScript with {@see data_for_js()}.
      *
      * @param string $identifier the desired string.
      * @param string $component the language file to look in.
@@ -1232,9 +1293,11 @@ class page_requirements_manager {
         if (!$component) {
             throw new coding_exception('The $component parameter is required for page_requirements_manager::string_for_js().');
         }
-        if (isset($this->stringsforjs_as[$component][$identifier]) and $this->stringsforjs_as[$component][$identifier] !== $a) {
-            throw new coding_exception("Attempt to re-define already required string '$identifier' " .
-                    "from lang file '$component' with different \$a parameter?");
+        if (isset($this->stringsforjs_as[$component][$identifier]) && $this->stringsforjs_as[$component][$identifier] !== $a) {
+            throw new coding_exception(
+                "Attempt to re-define already required string '$identifier' " .
+                    "from lang file '$component' with different \$a parameter?",
+            );
         }
         if (!isset($this->stringsforjs[$component][$identifier])) {
             $this->stringsforjs[$component][$identifier] = new lang_string($identifier, $component, $a);
@@ -1245,7 +1308,7 @@ class page_requirements_manager {
     /**
      * Make an array of language strings available for JS.
      *
-     * This function calls the above function {@link string_for_js()} for each requested
+     * This function calls the above function {@see string_for_js()} for each requested
      * string in the $identifiers array that is passed to the argument for a single module
      * passed in $module.
      *
@@ -1297,9 +1360,9 @@ class page_requirements_manager {
      * @param bool $inhead initialise in head
      * @return void
      */
-    public function data_for_js($variable, $data, $inhead=false) {
+    public function data_for_js($variable, $data, $inhead = false) {
         $where = $inhead ? 'head' : 'footer';
-        $this->jsinitvariables[$where][] = array($variable, $data);
+        $this->jsinitvariables[$where][] = [$variable, $data];
     }
 
     /**
@@ -1308,10 +1371,15 @@ class page_requirements_manager {
      * @param mixed $selector standard YUI selector for elements, may be array or string, element id is in the form "#idvalue"
      * @param string $event A valid DOM event (click, mousedown, change etc.)
      * @param string $function The name of the function to call
-     * @param array  $arguments An optional array of argument parameters to pass to the function
+     * @param null|array $arguments An optional array of argument parameters to pass to the function
      */
-    public function event_handler($selector, $event, $function, array $arguments = null) {
-        $this->eventhandlers[] = array('selector'=>$selector, 'event'=>$event, 'function'=>$function, 'arguments'=>$arguments);
+    public function event_handler(
+        $selector,
+        $event,
+        $function,
+        ?array $arguments = null,
+    ) {
+        $this->eventhandlers[] = ['selector' => $selector, 'event' => $event, 'function' => $function, 'arguments' => $arguments];
     }
 
     /**
@@ -1439,21 +1507,27 @@ EOF;
         $code = '';
         if ($this->yui3loader->combine) {
             if (!empty($this->yuicssmodules)) {
-                $modules = array();
+                $modules = [];
                 foreach ($this->yuicssmodules as $module) {
                     $modules[] = "$CFG->yui3version/$module/$module-min.css";
                 }
-                $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->comboBase.implode('&amp;', $modules).'" />';
+                $code .= '<link rel="stylesheet" type="text/css" href="' .
+                    $this->yui3loader->comboBase . implode('&amp;', $modules) . '" />';
             }
-            $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
-
+            $code .= '<link rel="stylesheet" type="text/css" href="' .
+                $this->yui3loader->local_comboBase . 'rollup/' . $CFG->yui3version . '/yui-moodlesimple' . $yuiformat .
+                '.css" />';
         } else {
             if (!empty($this->yuicssmodules)) {
                 foreach ($this->yuicssmodules as $module) {
-                    $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->base.$module.'/'.$module.'-min.css" />';
+                    $code .= '<link rel="stylesheet" type="text/css"href="' .
+                        $this->yui3loader->base . $module . '/' . $module .
+                        '-min.css" />';
                 }
             }
-            $code .= '<link rel="stylesheet" type="text/css" href="'.$this->yui3loader->local_comboBase.'rollup/'.$CFG->yui3version.'/yui-moodlesimple' . $yuiformat . '.css" />';
+            $code .= '<link rel="stylesheet" type="text/css" href="' .
+                $this->yui3loader->local_comboBase . 'rollup/' . $CFG->yui3version . '/yui-moodlesimple' . $yuiformat .
+                '.css" />';
         }
 
         if ($this->yui3loader->filter === 'RAW') {
@@ -1489,9 +1563,9 @@ EOF;
             $rollupversion .= '_' . $CFG->yuipatchlevel;
         }
 
-        $baserollups = array(
+        $baserollups = [
             'rollup/' . $rollupversion . "/yui-moodlesimple{$yuiformat}.js",
-        );
+        ];
 
         if ($this->yui3loader->combine) {
             return '<script src="' .
@@ -1501,11 +1575,10 @@ EOF;
         } else {
             $code = '';
             foreach ($baserollups as $rollup) {
-                $code .= '<script src="'.$this->yui3loader->local_comboBase.$rollup.'"></script>';
+                $code .= '<script src="' . $this->yui3loader->local_comboBase . $rollup . '"></script>';
             }
             return $code;
         }
-
     }
 
     /**
@@ -1518,7 +1591,7 @@ EOF;
         // Please note custom CSS is strongly discouraged,
         // because it can not be overridden by themes!
         // It is suitable only for things like mod/data which accepts CSS from teachers.
-        $attributes = array('rel'=>'stylesheet', 'type'=>'text/css');
+        $attributes = ['rel' => 'stylesheet', 'type' => 'text/css'];
 
         // Add the YUI code first. We want this to be overridden by any Moodle CSS.
         $code = $this->get_yui3lib_headcss();
@@ -1528,7 +1601,11 @@ EOF;
         // As of IE8 + YUI3.1.1 the reference stylesheet (firstthemesheet) gets
         // ignored whenever another resource is added until such time as a redraw
         // is forced, usually by moving the mouse over the affected element.
-        $code .= html_writer::tag('script', '/** Required in order to fix style inclusion problems in IE with YUI **/', array('id'=>'firstthemesheet', 'type'=>'text/css'));
+        $code .= html_writer::tag(
+            'script',
+            '/** Required in order to fix style inclusion problems in IE with YUI **/',
+            ['id' => 'firstthemesheet', 'type' => 'text/css'],
+        );
 
         $urls = $this->cssthemeurls + $this->cssurls;
         foreach ($urls as $url) {
@@ -1550,7 +1627,7 @@ EOF;
         if (empty($this->extramodules)) {
             return '';
         }
-        return html_writer::script(js_writer::function_call('M.yui.add_module', array($this->extramodules)));
+        return html_writer::script(js_writer::function_call('M.yui.add_module', [$this->extramodules]));
     }
 
     /**
@@ -1588,7 +1665,7 @@ EOF;
 
         // Set up global YUI3 loader object - this should contain all code needed by plugins.
         // Note: in JavaScript just use "YUI().use('overlay', function(Y) { .... });",
-        //       this needs to be done before including any other script.
+        // this needs to be done before including any other script.
         $js .= $this->YUI_config->get_config_functions();
         $js .= js_writer::set_variable('YUI_config', $this->YUI_config, false) . "\n";
         $js .= "M.yui.loader = {modules: {}};\n"; // Backwards compatibility only, not used any more.
@@ -1600,7 +1677,7 @@ EOF;
         if ($this->jsinitvariables['head']) {
             $js = '';
             foreach ($this->jsinitvariables['head'] as $data) {
-                list($var, $value) = $data;
+                [$var, $value] = $data;
                 $js .= js_writer::set_variable($var, $value, true);
             }
             $output .= html_writer::script($js);
@@ -1670,7 +1747,7 @@ EOF;
         if ($CFG->debugdeveloper) {
             $logconfig->level = 'trace';
         }
-        $this->js_call_amd('core/log', 'setConfig', array($logconfig));
+        $this->js_call_amd('core/log', 'setConfig', [$logconfig]);
         // Add any global JS that needs to run on all pages.
         $this->js_call_amd('core/page_global', 'init');
         $this->js_call_amd('core/utility');
@@ -1692,7 +1769,7 @@ EOF;
 
         // Add all needed strings.
         // First add core strings required for some dialogues.
-        $this->strings_for_js(array(
+        $this->strings_for_js([
             'confirm',
             'yes',
             'no',
@@ -1705,17 +1782,17 @@ EOF;
             // TODO MDL-70830 shortforms should preload the collapseall/expandall strings properly.
             'collapseall',
             'expandall',
-        ), 'moodle');
-        $this->strings_for_js(array(
+        ], 'moodle');
+        $this->strings_for_js([
             'debuginfo',
             'line',
             'stacktrace',
-        ), 'debug');
+        ], 'debug');
         $this->string_for_js('labelsep', 'langconfig');
         if (!empty($this->stringsforjs)) {
-            $strings = array();
-            foreach ($this->stringsforjs as $component=>$v) {
-                foreach($v as $indentifier => $langstring) {
+            $strings = [];
+            foreach ($this->stringsforjs as $component => $v) {
+                foreach ($v as $indentifier => $langstring) {
                     $strings[$component][$indentifier] = $langstring->out();
                 }
             }
@@ -1726,7 +1803,7 @@ EOF;
         if ($this->jsinitvariables['footer']) {
             $js = '';
             foreach ($this->jsinitvariables['footer'] as $data) {
-                list($var, $value) = $data;
+                [$var, $value] = $data;
                 $js .= js_writer::set_variable($var, $value, true);
             }
             $output .= html_writer::script($js);
@@ -1766,9 +1843,9 @@ EOF;
     /**
      * Should we generate a bit of content HTML that is only required once  on
      * this page (e.g. the contents of the modchooser), now? Basically, we call
-     * {@link has_one_time_item_been_created()}, and if the thing has not already
+     * {@see has_one_time_item_been_created()}, and if the thing has not already
      * been output, we return true to tell the caller to generate it, and also
-     * call {@link set_one_time_item_created()} to record the fact that it is
+     * call {@see set_one_time_item_created()} to record the fact that it is
      * about to be generated.
      *
      * That is, a typical usage pattern (in a renderer method) is:
@@ -1796,7 +1873,7 @@ EOF;
      * Has a particular bit of HTML that is only required once  on this page
      * (e.g. the contents of the modchooser) already been generated?
      *
-     * Normally, you can use the {@link should_create_one_time_item_now()} helper
+     * Normally, you can use the {@see should_create_one_time_item_now()} helper
      * method rather than calling this method directly.
      *
      * @param string $thing identifier for the bit of content. Should be of the form
@@ -1811,7 +1888,7 @@ EOF;
      * Indicate that a particular bit of HTML that is only required once on this
      * page (e.g. the contents of the modchooser) has been generated (or is about to be)?
      *
-     * Normally, you can use the {@link should_create_one_time_item_now()} helper
+     * Normally, you can use the {@see should_create_one_time_item_now()} helper
      * method rather than calling this method directly.
      *
      * @param string $thing identifier for the bit of content. Should be of the form
diff --git a/lib/classes/output/requirements/yui.php b/lib/classes/output/requirements/yui.php
index 367177fc80b..58a695191c2 100644
--- a/lib/classes/output/requirements/yui.php
+++ b/lib/classes/output/requirements/yui.php
@@ -46,8 +46,8 @@ class yui {
     public $combine;
     public $filter = null;
     public $insertBefore = 'firstthemesheet';
-    public $groups = array();
-    public $modules = array();
+    public $groups = [];
+    public $modules = [];
     /** @var array The log sources that should be not be logged. */
     public $logInclude = [];
     /** @var array Tog sources that should be logged. */
@@ -58,7 +58,7 @@ class yui {
     /**
      * @var array List of functions used by the YUI Loader group pattern recognition.
      */
-    protected $jsconfigfunctions = array();
+    protected $jsconfigfunctions = [];
 
     /**
      * Create a new group within the YUI_config system.
@@ -70,7 +70,10 @@ class yui {
      */
     public function add_group($name, $config) {
         if (isset($this->groups[$name])) {
-            throw new coding_exception("A YUI configuration group for '{$name}' already exists. To make changes to this group use YUI_config->update_group().");
+            throw new coding_exception(
+                "A YUI configuration group for '{$name}' already exists. " .
+                    'To make changes to this group use YUI_config->update_group().',
+            );
         }
         $this->groups[$name] = $config;
     }
@@ -88,7 +91,10 @@ class yui {
      */
     public function update_group($name, $config) {
         if (!isset($this->groups[$name])) {
-            throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
+            throw new coding_exception(
+                'The Moodle YUI module does not exist. ' .
+                    'You must define the moodle module config using YUI_config->add_module_config first.',
+            );
         }
         $this->groups[$name] = $config;
     }
@@ -101,13 +107,15 @@ class yui {
      * The JS function your write will be passed a single argument 'name' containing the
      * name of the module being loaded.
      *
-     * @param $function String the body of the JavaScript function. This should be used i
+     * @param string $function String the body of the JavaScript function. This should be used i
      * @return string the name of the function to use in the group pattern configuration.
      */
     public function set_config_function($function) {
         $configname = 'yui' . (count($this->jsconfigfunctions) + 1) . 'ConfigFn';
         if (isset($this->jsconfigfunctions[$configname])) {
-            throw new coding_exception("A YUI config function with this name already exists. Config function names must be unique.");
+            throw new coding_exception(
+                "A YUI config function with this name already exists. Config function names must be unique.",
+            );
         }
         $this->jsconfigfunctions[$configname] = $function;
         return '@' . $configname . '@';
@@ -119,7 +127,7 @@ class yui {
      *
      * When jsrev is positive, the function is minified and stored in a MUC cache for subsequent uses.
      *
-     * @param $file The path to the JavaScript function used for YUI configuration.
+     * @param string $file The path to the JavaScript function used for YUI configuration.
      * @return string the name of the function to use in the group pattern configuration.
      */
     public function set_config_source($file) {
@@ -136,7 +144,7 @@ class yui {
             $configfn = $cache->get($keyname);
             if ($configfn === false) {
                 require_once($CFG->libdir . '/jslib.php');
-                $configfn = core_minify::js_files(array($fullpath));
+                $configfn = core_minify::js_files([$fullpath]);
                 $cache->set($keyname, $configfn);
             }
         }
@@ -161,7 +169,7 @@ class yui {
     /**
      * Update the header JavaScript with any required modification for the YUI Loader.
      *
-     * @param $js String The JavaScript to manipulate.
+     * @param string $js String The JavaScript to manipulate.
      * @return string the modified JS string.
      */
     public function update_header_js($js) {
@@ -187,10 +195,13 @@ class yui {
     public function add_module_config($name, $config, $group = null) {
         if ($group) {
             if (!isset($this->groups[$name])) {
-                throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
+                throw new coding_exception(
+                    'The Moodle YUI module does not exist. ' .
+                        'You must define the moodle module config using YUI_config->add_module_config first.',
+                );
             }
             if (!isset($this->groups[$group]['modules'])) {
-                $this->groups[$group]['modules'] = array();
+                $this->groups[$group]['modules'] = [];
             }
             $modules = &$this->groups[$group]['modules'];
         } else {
@@ -212,16 +223,19 @@ class yui {
     public function add_moodle_metadata() {
         global $CFG;
         if (!isset($this->groups['moodle'])) {
-            throw new coding_exception('The Moodle YUI module does not exist. You must define the moodle module config using YUI_config->add_module_config first.');
+            throw new coding_exception(
+                'The Moodle YUI module does not exist. ' .
+                    'You must define the moodle module config using YUI_config->add_module_config first.',
+            );
         }
 
         if (!isset($this->groups['moodle']['modules'])) {
-            $this->groups['moodle']['modules'] = array();
+            $this->groups['moodle']['modules'] = [];
         }
 
         $cache = cache::make('core', 'yuimodules');
         if (!isset($CFG->jsrev) || $CFG->jsrev == -1) {
-            $metadata = array();
+            $metadata = [];
             $metadata = $this->get_moodle_metadata();
             $cache->delete('metadata');
         } else {
@@ -233,8 +247,10 @@ class yui {
         }
 
         // Merge with any metadata added specific to this page which was added manually.
-        $this->groups['moodle']['modules'] = array_merge($this->groups['moodle']['modules'],
-                $metadata);
+        $this->groups['moodle']['modules'] = array_merge(
+            $this->groups['moodle']['modules'],
+            $metadata
+        );
     }
 
     /**
@@ -246,7 +262,7 @@ class yui {
      * @return array of module metadata
      */
     private function get_moodle_metadata() {
-        $moodlemodules = array();
+        $moodlemodules = [];
         // Core isn't a plugin type or subsystem - handle it seperately.
         if ($module = $this->get_moodle_path_metadata(core_component::get_component_directory('core'))) {
             $moodlemodules = array_merge($moodlemodules, $module);
@@ -286,11 +302,11 @@ class yui {
     private function get_moodle_path_metadata($path) {
         // Add module metadata is stored in frankenstyle_modname/yui/src/yui_modname/meta/yui_modname.json.
         $baseyui = $path . '/yui/src';
-        $modules = array();
+        $modules = [];
         if (is_dir($baseyui)) {
             $items = new DirectoryIterator($baseyui);
             foreach ($items as $item) {
-                if ($item->isDot() or !$item->isDir()) {
+                if ($item->isDot() || !$item->isDir()) {
                     continue;
                 }
                 $metafile = realpath($baseyui . '/' . $item . '/meta/' . $item . '.json');
@@ -324,35 +340,34 @@ class yui {
             // If we are using the local combobase in the loader, we can add a group and still make use of the combo
             // loader. We just need to specify a different root which includes a slightly different YUI version number
             // to include our patchlevel.
-            $patterns = array();
-            $modules = array();
+            $patterns = [];
+            $modules = [];
             foreach ($patchedmodules as $modulename) {
                 // We must define the pattern and module here so that the loader uses our group configuration instead of
                 // the standard module definition. We may lose some metadata provided by upstream but this will be
                 // loaded when the module is loaded anyway.
-                $patterns[$modulename] = array(
+                $patterns[$modulename] = [
                     'group' => 'yui-patched',
-                );
-                $modules[$modulename] = array();
+                ];
+                $modules[$modulename] = [];
             }
 
             // Actually add the patch group here.
-            $this->add_group('yui-patched', array(
+            $this->add_group('yui-patched', [
                 'combine' => true,
                 'root' => $subversion . '/',
                 'patterns' => $patterns,
                 'modules' => $modules,
-            ));
-
+            ]);
         } else {
             // The CDN is in use - we need to instead use the local combobase for this module and override the modules
             // definition. We cannot use the local base - we must use the combobase because we cannot invalidate the
             // local base in browser caches.
             $fullpathbase = $combobase . $subversion . '/';
             foreach ($patchedmodules as $modulename) {
-                $this->modules[$modulename] = array(
-                    'fullpath' => $fullpathbase . $modulename . '/' . $modulename . '-min.js'
-                );
+                $this->modules[$modulename] = [
+                    'fullpath' => $fullpathbase . $modulename . '/' . $modulename . '-min.js',
+                ];
             }
         }
     }
diff --git a/lib/classes/output/select_menu.php b/lib/classes/output/select_menu.php
index ee512815299..e642c70b6c6 100644
--- a/lib/classes/output/select_menu.php
+++ b/lib/classes/output/select_menu.php
@@ -83,7 +83,7 @@ class select_menu implements renderable, templatable {
                             'name' => $groupname,
                             'isgroup' => true,
                             'id' => \html_writer::random_id('select-menu-group'),
-                            'options' => []
+                            'options' => [],
                         ];
                     }
                     foreach ($optoptions as $optvalue => $optoption) {
diff --git a/lib/classes/output/single_button.php b/lib/classes/output/single_button.php
index c2dbfb607de..853f8d83f08 100644
--- a/lib/classes/output/single_button.php
+++ b/lib/classes/output/single_button.php
@@ -40,7 +40,7 @@ class single_button implements renderable {
         self::BUTTON_SUCCESS,
         self::BUTTON_DANGER,
         self::BUTTON_WARNING,
-        self::BUTTON_INFO
+        self::BUTTON_INFO,
     ];
 
     /**
@@ -117,7 +117,7 @@ class single_button implements renderable {
     /**
      * @var array List of attached actions
      */
-    public $actions = array();
+    public $actions = [];
 
     /**
      * @var array $params URL Params
@@ -143,8 +143,13 @@ class single_button implements renderable {
      * @param string $type whether this is a primary button or another type, used for styling
      * @param array $attributes Attributes for the HTML button tag
      */
-    public function __construct(moodle_url $url, $label, $method = 'post', $type = self::BUTTON_SECONDARY,
-        $attributes = []) {
+    public function __construct(
+        moodle_url $url,
+        $label,
+        $method = 'post',
+        $type = self::BUTTON_SECONDARY,
+        $attributes = []
+    ) {
         if (is_bool($type)) {
             debugging('The boolean $primary is deprecated and replaced by $type,
             use single_button::BUTTON_PRIMARY or self::BUTTON_SECONDARY instead');
@@ -262,7 +267,7 @@ class single_button implements renderable {
 
         // Button actions.
         $actions = $this->actions;
-        $data->actions = array_map(function($action) use ($output) {
+        $data->actions = array_map(function ($action) use ($output) {
             return $action->export_for_template($output);
         }, $actions);
         $data->hasactions = !empty($data->actions);
diff --git a/lib/classes/output/single_select.php b/lib/classes/output/single_select.php
index 6e7954eab42..d4bfa8cc084 100644
--- a/lib/classes/output/single_select.php
+++ b/lib/classes/output/single_select.php
@@ -33,16 +33,15 @@ use stdClass;
  * @category output
  */
 class single_select implements renderable, templatable {
-
     /**
      * @var moodle_url Target url - includes hidden fields
      */
-    var $url;
+    public $url;
 
     /**
      * @var string Name of the select element.
      */
-    var $name;
+    public $name;
 
     /**
      * @var array $options associative array value=>label ex.: array(1=>'One, 2=>Two)
@@ -50,62 +49,62 @@ class single_select implements renderable, templatable {
      *         array(array('Odd'=>array(1=>'One', 3=>'Three)), array('Even'=>array(2=>'Two')))
      *         array(1=>'One', '--1uniquekey'=>array('More'=>array(2=>'Two', 3=>'Three')))
      */
-    var $options;
+    public $options;
 
     /**
      * @var string Selected option
      */
-    var $selected;
+    public $selected;
 
     /**
      * @var array Nothing selected
      */
-    var $nothing;
+    public $nothing;
 
     /**
      * @var array Extra select field attributes
      */
-    var $attributes = array();
+    public $attributes = [];
 
     /**
      * @var string Button label
      */
-    var $label = '';
+    public $label = '';
 
     /**
      * @var array Button label's attributes
      */
-    var $labelattributes = array();
+    public $labelattributes = [];
 
     /**
      * @var string Form submit method post or get
      */
-    var $method = 'get';
+    public $method = 'get';
 
     /**
      * @var string Wrapping div class
      */
-    var $class = 'singleselect';
+    public $class = 'singleselect';
 
     /**
      * @var bool True if button disabled, false if normal
      */
-    var $disabled = false;
+    public $disabled = false;
 
     /**
      * @var string Button tooltip
      */
-    var $tooltip = null;
+    public $tooltip = null;
 
     /**
      * @var string Form id
      */
-    var $formid = null;
+    public $formid = null;
 
     /**
      * @var help_icon The help icon for this element.
      */
-    var $helpicon = null;
+    public $helpicon = null;
 
     /** @var component_action[] component action. */
     public $actions = [];
@@ -119,7 +118,14 @@ class single_select implements renderable, templatable {
      * @param ?array $nothing
      * @param string $formid
      */
-    public function __construct(moodle_url $url, $name, array $options, $selected = '', $nothing = array('' => 'choosedots'), $formid = null) {
+    public function __construct(
+        moodle_url $url,
+        $name,
+        array $options,
+        $selected = '',
+        $nothing = ['' => 'choosedots'],
+        $formid = null,
+    ) {
         $this->url      = $url;
         $this->name     = $name;
         $this->options  = $options;
@@ -135,7 +141,7 @@ class single_select implements renderable, templatable {
      * @param string $confirmmessage The yes/no confirmation question. If "Yes" is clicked, the original action will occur.
      */
     public function add_confirm_action($confirmmessage) {
-        $this->add_action(new component_action('submit', 'M.util.show_confirm_dialog', array('message' => $confirmmessage)));
+        $this->add_action(new component_action('submit', 'M.util.show_confirm_dialog', ['message' => $confirmmessage]));
     }
 
     /**
@@ -172,10 +178,9 @@ class single_select implements renderable, templatable {
      * @param string $label
      * @param array $attributes (optional)
      */
-    public function set_label($label, $attributes = array()) {
+    public function set_label($label, $attributes = []) {
         $this->label = $label;
         $this->labelattributes = $attributes;
-
     }
 
     /**
@@ -207,7 +212,7 @@ class single_select implements renderable, templatable {
         unset($attributes['disabled']);
 
         // Map the attributes.
-        $data->attributes = array_map(function($key) use ($attributes) {
+        $data->attributes = array_map(function ($key) use ($attributes) {
             return ['name' => $key, 'value' => $attributes[$key]];
         }, array_keys($attributes));
 
@@ -260,7 +265,7 @@ class single_select implements renderable, templatable {
                     $data->options[] = [
                         'name' => $optgroupname,
                         'optgroup' => true,
-                        'options' => $sublist
+                        'options' => $sublist,
                     ];
                 }
             } else {
@@ -268,7 +273,7 @@ class single_select implements renderable, templatable {
                     'value' => $value,
                     'name' => $options[$value],
                     'selected' => strval($this->selected) === strval($value),
-                    'optgroup' => false
+                    'optgroup' => false,
                 ];
 
                 if ($hasnothing && $nothingkey === $value) {
diff --git a/lib/classes/output/sticky_footer.php b/lib/classes/output/sticky_footer.php
index fdb88d57251..06e7e3723da 100644
--- a/lib/classes/output/sticky_footer.php
+++ b/lib/classes/output/sticky_footer.php
@@ -33,7 +33,6 @@ namespace core\output;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class sticky_footer implements named_templatable, renderable {
-
     /**
      * @var string content of the sticky footer.
      */
diff --git a/lib/classes/output/tabobject.php b/lib/classes/output/tabobject.php
index 7d7fa865833..d0943e6b166 100644
--- a/lib/classes/output/tabobject.php
+++ b/lib/classes/output/tabobject.php
@@ -23,28 +23,29 @@ use moodle_url;
  *
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @package core
+ * @copyright Marina Glancy
  */
 class tabobject implements renderable, templatable {
     /** @var string unique id of the tab in this tree, it is used to find selected and/or inactive tabs */
-    var $id;
+    public $id;
     /** @var moodle_url|string link */
-    var $link;
+    public $link;
     /** @var string text on the tab */
-    var $text;
+    public $text;
     /** @var string title under the link, by defaul equals to text */
-    var $title;
+    public $title;
     /** @var bool whether to display a link under the tab name when it's selected */
-    var $linkedwhenselected = false;
+    public $linkedwhenselected = false;
     /** @var bool whether the tab is inactive */
-    var $inactive = false;
+    public $inactive = false;
     /** @var bool indicates that this tab's child is selected */
-    var $activated = false;
+    public $activated = false;
     /** @var bool indicates that this tab is selected */
-    var $selected = false;
+    public $selected = false;
     /** @var array stores children tabobjects */
-    var $subtree = array();
+    public $subtree = [];
     /** @var int level of tab in the tree, 0 for root (instance of tabtree), 1 for the first row of tabs */
-    var $level = 1;
+    public $level = 1;
 
     /**
      * Constructor
@@ -140,7 +141,6 @@ class tabobject implements renderable, templatable {
             'level' => $this->level,
         ];
     }
-
 }
 
 // Alias this class to the old name.
diff --git a/lib/classes/output/tabtree.php b/lib/classes/output/tabtree.php
index 62a58a25694..0c47b4cb69b 100644
--- a/lib/classes/output/tabtree.php
+++ b/lib/classes/output/tabtree.php
@@ -87,7 +87,7 @@ class tabtree extends tabobject {
 
         return (object) [
             'tabs' => $tabs,
-            'secondrow' => $secondrow ? $secondrow->export_for_template($output) : false
+            'secondrow' => $secondrow ? $secondrow->export_for_template($output) : false,
         ];
     }
 }
diff --git a/lib/classes/output/theme_config.php b/lib/classes/output/theme_config.php
index 4edc1b65697..3a056592ac0 100644
--- a/lib/classes/output/theme_config.php
+++ b/lib/classes/output/theme_config.php
@@ -33,6 +33,9 @@ use moodle_page;
 use moodle_url;
 use stdClass;
 
+// phpcs:disable moodle.NamingConventions.ValidVariableName.VariableNameUnderscore
+// phpcs:disable moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
+
 /**
  * This class represents the configuration variables of a Moodle theme.
  *
@@ -44,7 +47,7 @@ use stdClass;
  * file, you can just ignore those, and the following information for developers.
  *
  * Normally, to create an instance of this class, you should use the
- * {@link theme_config::load()} factory method to load a themes config.php file.
+ * {@see theme_config::load()} factory method to load a themes config.php file.
  * However, normally you don't need to bother, because moodle_page (that is, $PAGE)
  * will create one for you, accessible as $PAGE->theme.
  *
@@ -54,7 +57,6 @@ use stdClass;
  * @category output
  */
 class theme_config {
-
     /**
      * @var string Default theme, used when requested theme not found.
      */
@@ -66,7 +68,7 @@ class theme_config {
     /**
      * @var array You can base your theme on other themes by linking to the other theme as
      * parents. This lets you use the CSS and layouts from the other themes
-     * (see {@link theme_config::$layouts}).
+     * (see {@see theme_config::$layouts}).
      * That makes it easy to create a new theme that is similar to another one
      * but with a few changes. In this themes CSS you only need to override
      * those rules you want to change.
@@ -77,7 +79,7 @@ class theme_config {
      * @var array The names of all the stylesheets from this theme that you would
      * like included, in order. Give the names of the files without .css.
      */
-    public $sheets = array();
+    public $sheets = [];
 
     /**
      * @var array The names of all the stylesheets from parents that should be excluded.
@@ -96,7 +98,7 @@ class theme_config {
      * @var array List of style sheets that are included in the text editor bodies.
      * Sheets from parent themes are used automatically and can not be excluded.
      */
-    public $editor_sheets = array();
+    public $editor_sheets = [];
 
     /**
      * @var bool Whether a fallback version of the stylesheet will be used
@@ -108,13 +110,13 @@ class theme_config {
      * @var array The names of all the javascript files this theme that you would
      * like included from head, in order. Give the names of the files without .js.
      */
-    public $javascripts = array();
+    public $javascripts = [];
 
     /**
      * @var array The names of all the javascript files this theme that you would
      * like included from footer, in order. Give the names of the files without .js.
      */
-    public $javascripts_footer = array();
+    public $javascripts_footer = [];
 
     /**
      * @var array The names of all the javascript files from parents that should
@@ -172,11 +174,11 @@ class theme_config {
      * that someone added blocks using a different theme that used different region
      * names, and then switched to this theme.)
      */
-    public $layouts = array();
+    public $layouts = [];
 
     /**
      * @var string Name of the renderer factory class to use. Must implement the
-     * {@link renderer_factory} interface.
+     * {@see renderer_factory} interface.
      *
      * This is an advanced feature. Moodle output is generated by 'renderers',
      * you can customise the HTML that is output by writing custom renderers,
@@ -186,8 +188,8 @@ class theme_config {
      * There are some renderer factories supplied with Moodle. Please follow these
      * links to see what they do.
      * <ul>
-     * <li>{@link standard_renderer_factory} - the default.</li>
-     * <li>{@link theme_overridden_renderer_factory} - use this if you want to write
+     * <li>{@see standard_renderer_factory} - the default.</li>
+     * <li>{@see theme_overridden_renderer_factory} - use this if you want to write
      *      your own custom renderers in a lib.php file in this theme (or the parent theme).</li>
      * </ul>
      */
@@ -268,7 +270,7 @@ class theme_config {
      */
     public $requiredblocks = false;
 
-    //==Following properties are not configurable from theme config.php==
+    // The Following properties are not configurable from theme config.php.
 
     /**
      * @var string The name of this theme. Set automatically when this theme is
@@ -304,7 +306,7 @@ class theme_config {
      * @var array list of YUI CSS modules to be included on each page. This may be used
      * to remove cssreset and use cssnormalise module instead.
      */
-    public $yuicssmodules = array('cssreset', 'cssfonts', 'cssgrids', 'cssbase');
+    public $yuicssmodules = ['cssreset', 'cssfonts', 'cssgrids', 'cssbase'];
 
     /**
      * An associative array of block manipulations that should be made if the user is using an rtl language.
@@ -312,7 +314,7 @@ class theme_config {
      * This is used when displaying blocks for regions only.
      * @var array
      */
-    public $blockrtlmanipulations = array();
+    public $blockrtlmanipulations = [];
 
     /**
      * @var renderer_factory Instance of the renderer_factory implementation
@@ -323,7 +325,7 @@ class theme_config {
     /**
      * @var array List of parent config objects.
      **/
-    protected $parent_configs = array();
+    protected $parent_configs = [];
 
     /**
      * Used to determine whether we can serve SVG images or not.
@@ -365,7 +367,7 @@ class theme_config {
 
     /**
      * Sets the render method that should be used for rendering custom block regions by scripts such as my/index.php
-     * Defaults to {@link core_renderer::blocks_for_region()}
+     * Defaults to {@see core_renderer::blocks_for_region()}
      * @var string
      */
     public $blockrendermethod = null;
@@ -435,27 +437,24 @@ class theme_config {
     public static function load($themename) {
         global $CFG;
 
-        // load theme settings from db
+        // Load theme settings from db.
         try {
-            $settings = get_config('theme_'.$themename);
+            $settings = get_config('theme_' . $themename);
         } catch (dml_exception $e) {
-            // most probably moodle tables not created yet
+            // Most probably moodle tables not created yet.
             $settings = new stdClass();
         }
 
         if ($config = self::find_theme_config($themename, $settings)) {
             return new self($config);
-
         } else if ($themename == self::DEFAULT_THEME) {
-            throw new coding_exception('Default theme '.self::DEFAULT_THEME.' not available or broken!');
-
+            throw new coding_exception('Default theme ' . self::DEFAULT_THEME . ' not available or broken!');
         } else if ($config = self::find_theme_config($CFG->theme, $settings)) {
             debugging('This page should be using theme ' . $themename .
                     ' which cannot be initialised. Falling back to the site theme ' . $CFG->theme, DEBUG_NORMAL);
             return new self($config);
-
         } else {
-            // bad luck, the requested theme has some problems - admin see details in theme config
+            // Bad luck, the requested theme has some problems - admin see details in theme config.
             debugging('This page should be using theme ' . $themename .
                     ' which cannot be initialised. Nor can the site theme ' . $CFG->theme .
                     '. Falling back to ' . self::DEFAULT_THEME, DEBUG_NORMAL);
@@ -474,8 +473,8 @@ class theme_config {
      * @return array description of problems
      */
     public static function diagnose($themename) {
-        //TODO: MDL-21108
-        return array();
+        // TODO: MDL-21108.
+        return [];
     }
 
     /**
@@ -483,7 +482,7 @@ class theme_config {
      * @param stdClass $config
      */
     private function __construct($config) {
-        global $CFG; //needed for included lib.php files
+        global $CFG; // Needed for included lib.php files.
 
         $this->settings = $config->settings;
         $this->name     = $config->name;
@@ -507,49 +506,49 @@ class theme_config {
             'removedprimarynavitems',
         ];
 
-        foreach ($config as $key=>$value) {
+        foreach ($config as $key => $value) {
             if (in_array($key, $configurable)) {
                 $this->$key = $value;
             }
         }
 
-        // verify all parents and load configs and renderers
+        // Verify all parents and load configs and renderers.
         foreach ($this->parents as $parent) {
             if (!$parent_config = self::find_theme_config($parent, $this->settings)) {
-                // this is not good - better exclude faulty parents
+                // This is not good - better exclude faulty parents.
                 continue;
             }
-            $libfile = $parent_config->dir.'/lib.php';
+            $libfile = $parent_config->dir . '/lib.php';
             if (is_readable($libfile)) {
-                // theme may store various function here
+                // Theme may store various function here.
                 include_once($libfile);
             }
-            $renderersfile = $parent_config->dir.'/renderers.php';
+            $renderersfile = $parent_config->dir . '/renderers.php';
             if (is_readable($renderersfile)) {
-                // may contain core and plugin renderers and renderer factory
+                // May contain core and plugin renderers and renderer factory.
                 include_once($renderersfile);
             }
             $this->parent_configs[$parent] = $parent_config;
         }
-        $libfile = $this->dir.'/lib.php';
+        $libfile = $this->dir . '/lib.php';
         if (is_readable($libfile)) {
-            // theme may store various function here
+            // Theme may store various function here.
             include_once($libfile);
         }
-        $rendererfile = $this->dir.'/renderers.php';
+        $rendererfile = $this->dir . '/renderers.php';
         if (is_readable($rendererfile)) {
-            // may contain core and plugin renderers and renderer factory
+            // May contain core and plugin renderers and renderer factory.
             include_once($rendererfile);
         } else {
-            // check if renderers.php file is missnamed renderer.php
-            if (is_readable($this->dir.'/renderer.php')) {
-                debugging('Developer hint: '.$this->dir.'/renderer.php should be renamed to ' . $this->dir."/renderers.php.
+            // Check if renderers.php file is missnamed renderer.php.
+            if (is_readable($this->dir . '/renderer.php')) {
+                debugging('Developer hint: ' . $this->dir . '/renderer.php should be renamed to ' . $this->dir . "/renderers.php.
                     See: http://docs.moodle.org/dev/Output_renderers#Theme_renderers.", DEBUG_DEVELOPER);
             }
         }
 
-        // cascade all layouts properly
-        foreach ($baseconfig->layouts as $layout=>$value) {
+        // Cascade all layouts properly.
+        foreach ($baseconfig->layouts as $layout => $value) {
             if (!isset($this->layouts[$layout])) {
                 foreach ($this->parent_configs as $parent_config) {
                     if (isset($parent_config->layouts[$layout])) {
@@ -561,7 +560,7 @@ class theme_config {
             }
         }
 
-        //fix arrows if needed
+        // Fix arrows if needed.
         $this->check_theme_arrows();
     }
 
@@ -573,7 +572,7 @@ class theme_config {
      * @param moodle_page $page
      */
     public function init_page(moodle_page $page) {
-        $themeinitfunction = 'theme_'.$this->name.'_page_init';
+        $themeinitfunction = 'theme_' . $this->name . '_page_init';
         if (function_exists($themeinitfunction)) {
             $themeinitfunction($page);
         }
@@ -588,9 +587,9 @@ class theme_config {
      * (unlike &gt; &raquo;), and must be accompanied by text.
      */
     private function check_theme_arrows() {
-        if (!isset($this->rarrow) and !isset($this->larrow)) {
+        if (!isset($this->rarrow) && !isset($this->larrow)) {
             // Default, looks good in Win XP/IE 6, Win/Firefox 1.5, Win/Netscape 8...
-            // Also OK in Win 9x/2K/IE 5.x
+            // Also OK in Win 9x/2K/IE 5.x.
             $this->rarrow = '&#x25BA;';
             $this->larrow = '&#x25C4;';
             $this->uarrow = '&#x25B2;';
@@ -600,25 +599,29 @@ class theme_config {
             } else {
                 $uagent = $_SERVER['HTTP_USER_AGENT'];
             }
-            if (false !== strpos($uagent, 'Opera')
-                || false !== strpos($uagent, 'Mac')) {
+            if (
+                false !== strpos($uagent, 'Opera')
+                || false !== strpos($uagent, 'Mac')
+            ) {
                 // Looks good in Win XP/Mac/Opera 8/9, Mac/Firefox 2, Camino, Safari.
                 // Not broken in Mac/IE 5, Mac/Netscape 7 (?).
                 $this->rarrow = '&#x25B6;&#xFE0E;';
                 $this->larrow = '&#x25C0;&#xFE0E;';
-            }
-            elseif ((false !== strpos($uagent, 'Konqueror'))
-                || (false !== strpos($uagent, 'Android')))  {
+            } else if (
+                (false !== strpos($uagent, 'Konqueror'))
+                || (false !== strpos($uagent, 'Android'))
+            ) {
                 // The fonts on Android don't include the characters required for this to work as expected.
                 // So we use the same ones Konqueror uses.
                 $this->rarrow = '&rarr;';
                 $this->larrow = '&larr;';
                 $this->uarrow = '&uarr;';
                 $this->darrow = '&darr;';
-            }
-            elseif (isset($_SERVER['HTTP_ACCEPT_CHARSET'])
-                && false === stripos($_SERVER['HTTP_ACCEPT_CHARSET'], 'utf-8')) {
-                // (Win/IE 5 doesn't set ACCEPT_CHARSET, but handles Unicode.)
+            } else if (
+                isset($_SERVER['HTTP_ACCEPT_CHARSET'])
+                && false === stripos($_SERVER['HTTP_ACCEPT_CHARSET'], 'utf-8')
+            ) {
+                // Win/IE 5 doesn't set ACCEPT_CHARSET, but handles Unicode.
                 // To be safe, non-Unicode browsers!
                 $this->rarrow = '&gt;';
                 $this->larrow = '&lt;';
@@ -626,7 +629,7 @@ class theme_config {
                 $this->darrow = 'v';
             }
 
-            // RTL support - in RTL languages, swap r and l arrows
+            // RTL support - in RTL languages, swap r and l arrows.
             if (right_to_left()) {
                 $t = $this->rarrow;
                 $this->rarrow = $this->larrow;
@@ -642,12 +645,12 @@ class theme_config {
      * @return array
      */
     public function renderer_prefixes() {
-        global $CFG; // just in case the included files need it
+        global $CFG; // Just in case the included files need it.
 
-        $prefixes = array('theme_'.$this->name);
+        $prefixes = ['theme_' . $this->name];
 
         foreach ($this->parent_configs as $parent) {
-            $prefixes[] = 'theme_'.$parent->name;
+            $prefixes[] = 'theme_' . $parent->name;
         }
 
         return $prefixes;
@@ -659,7 +662,7 @@ class theme_config {
      * @param bool $encoded false means use & and true use &amp; in URLs
      * @return moodle_url
      */
-    public function editor_css_url($encoded=true) {
+    public function editor_css_url($encoded = true) {
         global $CFG;
         $rev = theme_get_revision();
         $type = 'editor';
@@ -701,14 +704,14 @@ class theme_config {
      * @return array
      */
     public function editor_css_files() {
-        $files = array();
+        $files = [];
 
         // First editor plugins.
         $plugins = core_component::get_plugin_list('editor');
         foreach ($plugins as $plugin => $fulldir) {
             $sheetfile = "$fulldir/editor_styles.css";
             if (is_readable($sheetfile)) {
-                $files['plugin_'.$plugin] = $sheetfile;
+                $files['plugin_' . $plugin] = $sheetfile;
             }
 
             $subplugintypes = core_component::get_subplugins("editor_{$plugin}") ?? [];
@@ -732,7 +735,7 @@ class theme_config {
             foreach ($parent_config->editor_sheets as $sheet) {
                 $sheetfile = "$parent_config->dir/style/$sheet.css";
                 if (is_readable($sheetfile)) {
-                    $files['parent_'.$parent_config->name.'_'.$sheet] = $sheetfile;
+                    $files['parent_' . $parent_config->name . '_' . $sheet] = $sheetfile;
                 }
             }
         }
@@ -741,7 +744,7 @@ class theme_config {
             foreach ($this->editor_sheets as $sheet) {
                 $sheetfile = "$this->dir/style/$sheet.css";
                 if (is_readable($sheetfile)) {
-                    $files['theme_'.$sheet] = $sheetfile;
+                    $files['theme_' . $sheet] = $sheetfile;
                 }
             }
         }
@@ -804,7 +807,7 @@ class theme_config {
 
         $rev = theme_get_revision();
 
-        $urls = array();
+        $urls = [];
 
         $svg = $this->use_svg_icons();
         $separate = (core_useragent::is_ie() && !core_useragent::check_ie_version('10'));
@@ -825,15 +828,15 @@ class theme_config {
                 if (!$svg) {
                     // We add a simple /_s to the start of the path.
                     // The underscore is used to ensure that it isn't a valid theme name.
-                    $slashargs .= '/_s'.$slashargs;
+                    $slashargs .= '/_s' . $slashargs;
                 }
-                $slashargs .= '/'.$this->name.'/'.$rev.'/'.$filename;
+                $slashargs .= '/' . $this->name . '/' . $rev . '/' . $filename;
                 if ($separate) {
                     $slashargs .= '/chunk0';
                 }
                 $url->set_slashargument($slashargs, 'noparam', true);
             } else {
-                $params = array('theme' => $this->name, 'rev' => $rev, 'type' => $filename);
+                $params = ['theme' => $this->name, 'rev' => $rev, 'type' => $filename];
                 if (!$svg) {
                     // We add an SVG param so that we know not to serve SVG images.
                     // We do this because all modern browsers support SVG and this param will one day be removed.
@@ -845,7 +848,6 @@ class theme_config {
                 $url->params($params);
             }
             $urls[] = $url;
-
         } else {
             $baseurl = new moodle_url('/theme/styles_debug.php');
 
@@ -864,33 +866,42 @@ class theme_config {
             }
             if (core_useragent::is_ie()) {
                 // Lalala, IE does not allow more than 31 linked CSS files from main document.
-                $urls[] = new moodle_url($baseurl, array('theme'=>$this->name, 'type'=>'ie', 'subtype'=>'plugins'));
-                foreach ($css['parents'] as $parent=>$sheets) {
+                $urls[] = new moodle_url($baseurl, ['theme' => $this->name, 'type' => 'ie', 'subtype' => 'plugins']);
+                foreach ($css['parents'] as $parent => $sheets) {
                     // We need to serve parents individually otherwise we may easily exceed the style limit IE imposes (4096).
-                    $urls[] = new moodle_url($baseurl, array('theme'=>$this->name,'type'=>'ie', 'subtype'=>'parents', 'sheet'=>$parent));
+                    $urls[] = new moodle_url($baseurl, [
+                        'theme' => $this->name,
+                        'type' => 'ie',
+                        'subtype' => 'parents',
+                        'sheet' => $parent,
+                    ]);
                 }
                 if ($this->get_scss_property()) {
                     // No need to define the type as IE here.
-                    $urls[] = new moodle_url($baseurl, array('theme' => $this->name, 'type' => 'scss'));
+                    $urls[] = new moodle_url($baseurl, ['theme' => $this->name, 'type' => 'scss']);
                 }
-                $urls[] = new moodle_url($baseurl, array('theme'=>$this->name, 'type'=>'ie', 'subtype'=>'theme'));
-
+                $urls[] = new moodle_url($baseurl, ['theme' => $this->name, 'type' => 'ie', 'subtype' => 'theme']);
             } else {
-                foreach ($css['plugins'] as $plugin=>$unused) {
-                    $urls[] = new moodle_url($baseurl, array('theme'=>$this->name,'type'=>'plugin', 'subtype'=>$plugin));
+                foreach ($css['plugins'] as $plugin => $unused) {
+                    $urls[] = new moodle_url($baseurl, ['theme' => $this->name, 'type' => 'plugin', 'subtype' => $plugin]);
                 }
-                foreach ($css['parents'] as $parent=>$sheets) {
-                    foreach ($sheets as $sheet=>$unused2) {
-                        $urls[] = new moodle_url($baseurl, array('theme'=>$this->name,'type'=>'parent', 'subtype'=>$parent, 'sheet'=>$sheet));
+                foreach ($css['parents'] as $parent => $sheets) {
+                    foreach ($sheets as $sheet => $unused2) {
+                        $urls[] = new moodle_url($baseurl, [
+                            'theme' => $this->name,
+                            'type' => 'parent',
+                            'subtype' => $parent,
+                            'sheet' => $sheet,
+                        ]);
                     }
                 }
                 foreach ($css['theme'] as $sheet => $filename) {
                     if ($sheet === self::SCSS_KEY) {
                         // This is the theme SCSS file.
-                        $urls[] = new moodle_url($baseurl, array('theme' => $this->name, 'type' => 'scss'));
+                        $urls[] = new moodle_url($baseurl, ['theme' => $this->name, 'type' => 'scss']);
                     } else {
                         // Sheet first in order to make long urls easier to read.
-                        $urls[] = new moodle_url($baseurl, array('sheet'=>$sheet, 'theme'=>$this->name, 'type'=>'theme'));
+                        $urls[] = new moodle_url($baseurl, ['sheet' => $sheet, 'theme' => $this->name, 'type' => 'theme']);
                     }
                 }
             }
@@ -1011,16 +1022,15 @@ class theme_config {
             return '';
         }
 
-        $cssfiles = array();
+        $cssfiles = [];
         $css = $this->get_css_files(true);
 
         if ($type === 'ie') {
             // IE is a sloppy browser with weird limits, sorry.
             if ($subtype === 'plugins') {
                 $cssfiles = $css['plugins'];
-
             } else if ($subtype === 'parents') {
-                if (empty($sheet)) {
+                if (empty($sheet)) { // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedIf
                     // Do not bother with the empty parent here.
                 } else {
                     // Build up the CSS for that parent so we can serve it as one file.
@@ -1038,17 +1048,14 @@ class theme_config {
                     }
                 }
             }
-
         } else if ($type === 'plugin') {
             if (isset($css['plugins'][$subtype])) {
                 $cssfiles[] = $css['plugins'][$subtype];
             }
-
         } else if ($type === 'parent') {
             if (isset($css['parents'][$subtype][$sheet])) {
                 $cssfiles[] = $css['parents'][$subtype][$sheet];
             }
-
         } else if ($type === 'theme') {
             if (isset($css['theme'][$sheet])) {
                 $cssfiles[] = $css['theme'][$sheet];
@@ -1061,7 +1068,7 @@ class theme_config {
             $contents = $this->post_process($contents);
             $comment = "/** Path: $type $subtype $sheet.' **/\n";
             $stats = '';
-            $csscontent .= $comment.$stats.$contents."\n\n";
+            $csscontent .= $comment . $stats . $contents . "\n\n";
         }
 
         return $csscontent;
@@ -1080,7 +1087,7 @@ class theme_config {
 
         // If editor has static CSS, include it.
         foreach ($cssfiles as $file) {
-            $css .= file_get_contents($file)."\n";
+            $css .= file_get_contents($file) . "\n";
         }
 
         // If editor has SCSS, compile and include it.
@@ -1105,10 +1112,10 @@ class theme_config {
         $cache = null;
         $cachekey = 'cssfiles';
         if ($themedesigner) {
-            require_once($CFG->dirroot.'/lib/csslib.php');
+            require_once($CFG->dirroot . '/lib/csslib.php');
             // We need some kind of caching here because otherwise the page navigation becomes
             // way too slow in theme designer mode. Feel free to create full cache definition later...
-            $cache = cache::make_from_params(cache_store::MODE_APPLICATION, 'core', 'themedesigner', array('theme' => $this->name));
+            $cache = cache::make_from_params(cache_store::MODE_APPLICATION, 'core', 'themedesigner', ['theme' => $this->name]);
             if ($files = $cache->get($cachekey)) {
                 if ($files['created'] > time() - THEME_DESIGNER_CACHE_LIFETIME) {
                     unset($files['created']);
@@ -1117,30 +1124,33 @@ class theme_config {
             }
         }
 
-        $cssfiles = array('plugins'=>array(), 'parents'=>array(), 'theme'=>array());
+        $cssfiles = ['plugins' => [], 'parents' => [], 'theme' => []];
 
         // Get all plugin sheets.
         $excludes = $this->resolve_excludes('plugins_exclude_sheets');
         if ($excludes !== true) {
-            foreach (core_component::get_plugin_types() as $type=>$unused) {
-                if ($type === 'theme' || (!empty($excludes[$type]) and $excludes[$type] === true)) {
+            foreach (core_component::get_plugin_types() as $type => $unused) {
+                if ($type === 'theme' || (!empty($excludes[$type]) && $excludes[$type] === true)) {
                     continue;
                 }
                 $plugins = core_component::get_plugin_list($type);
-                foreach ($plugins as $plugin=>$fulldir) {
-                    if (!empty($excludes[$type]) and is_array($excludes[$type])
-                            and in_array($plugin, $excludes[$type])) {
+                foreach ($plugins as $plugin => $fulldir) {
+                    if (
+                        !empty($excludes[$type])
+                        && is_array($excludes[$type])
+                        && in_array($plugin, $excludes[$type])
+                    ) {
                         continue;
                     }
 
                     // Get the CSS from the plugin.
                     $sheetfile = "$fulldir/styles.css";
                     if (is_readable($sheetfile)) {
-                        $cssfiles['plugins'][$type.'_'.$plugin] = $sheetfile;
+                        $cssfiles['plugins'][$type . '_' . $plugin] = $sheetfile;
                     }
 
                     // Create a list of candidate sheets from parents (direct parent last) and current theme.
-                    $candidates = array();
+                    $candidates = [];
                     foreach (array_reverse($this->parent_configs) as $parent_config) {
                         $candidates[] = $parent_config->name;
                     }
@@ -1150,7 +1160,7 @@ class theme_config {
                     foreach ($candidates as $candidate) {
                         $sheetthemefile = "$fulldir/styles_{$candidate}.css";
                         if (is_readable($sheetthemefile)) {
-                            $cssfiles['plugins'][$type.'_'.$plugin.'_'.$candidate] = $sheetthemefile;
+                            $cssfiles['plugins'][$type . '_' . $plugin . '_' . $candidate] = $sheetthemefile;
                         }
                     }
                 }
@@ -1162,12 +1172,14 @@ class theme_config {
         if ($excludes !== true) {
             foreach (array_reverse($this->parent_configs) as $parent_config) { // Base first, the immediate parent last.
                 $parent = $parent_config->name;
-                if (empty($parent_config->sheets) || (!empty($excludes[$parent]) and $excludes[$parent] === true)) {
+                if (empty($parent_config->sheets) || (!empty($excludes[$parent]) && $excludes[$parent] === true)) {
                     continue;
                 }
                 foreach ($parent_config->sheets as $sheet) {
-                    if (!empty($excludes[$parent]) && is_array($excludes[$parent])
-                            && in_array($sheet, $excludes[$parent])) {
+                    if (
+                        !empty($excludes[$parent]) && is_array($excludes[$parent])
+                            && in_array($sheet, $excludes[$parent])
+                    ) {
                         continue;
                     }
 
@@ -1180,7 +1192,6 @@ class theme_config {
             }
         }
 
-
         // Current theme sheets.
         // We first add the SCSS file because we want the CSS ones to
         // be included after the SCSS code.
@@ -1213,7 +1224,7 @@ class theme_config {
     protected function get_css_content_from_scss($themedesigner) {
         global $CFG;
 
-        list($paths, $scss) = $this->get_scss_property();
+        [$paths, $scss] = $this->get_scss_property();
         if (!$scss) {
             throw new coding_exception('The theme did not define a SCSS file, or it is not readable.');
         }
@@ -1228,11 +1239,11 @@ class theme_config {
         $cachedir = make_localcache_directory('scsscache-' . $this->name, false);
         $cacheoptions = [];
         if ($themedesigner) {
-            $cacheoptions = array(
+            $cacheoptions = [
                   'cacheDir' => $cachedir,
                   'prefix' => 'scssphp_',
                   'forceRefresh' => false,
-            );
+            ];
         } else {
             if (file_exists($cachedir)) {
                 remove_dir($cachedir);
@@ -1246,7 +1257,7 @@ class theme_config {
             // Enable source maps.
             $compiler->setSourceMapOptions([
                 'sourceMapBasepath' => str_replace('\\', '/', $CFG->dirroot),
-                'sourceMapRootpath' => $CFG->wwwroot . '/'
+                'sourceMapRootpath' => $CFG->wwwroot . '/',
             ]);
             $compiler->setSourceMap($compiler::SOURCE_MAP_INLINE);
         }
@@ -1263,7 +1274,6 @@ class theme_config {
         try {
             // Compile!
             $compiled = $compiler->to_css();
-
         } catch (\Exception $e) {
             $compiled = false;
             debugging('Error while compiling SCSS: ' . $e->getMessage(), DEBUG_DEVELOPER);
@@ -1321,7 +1331,7 @@ class theme_config {
      *
      * This is intended to be used by themes to inject some SCSS code
      * before it gets compiled. If you want to inject variables you
-     * should use {@link self::get_scss_variables()}.
+     * should use {@see self::get_scss_variables()}.
      *
      * @return string The SCSS code to inject.
      */
@@ -1329,7 +1339,7 @@ class theme_config {
         $content = '';
 
         // Getting all the candidate functions.
-        $candidates = array();
+        $candidates = [];
         foreach (array_reverse($this->parent_configs) as $parent_config) {
             if (!isset($parent_config->extrascsscallback)) {
                 continue;
@@ -1362,7 +1372,7 @@ class theme_config {
         $content = '';
 
         // Getting all the candidate functions.
-        $candidates = array();
+        $candidates = [];
         foreach (array_reverse($this->parent_configs) as $parent_config) {
             if (!isset($parent_config->prescsscallback)) {
                 continue;
@@ -1416,7 +1426,6 @@ class theme_config {
                 if ($scss && is_dir($path)) {
                     $paths[] = $path;
                 }
-
             }
 
             $this->scsscache = $scss !== null ? [$paths, $scss] : false;
@@ -1438,17 +1447,17 @@ class theme_config {
         global $CFG;
 
         $rev = theme_get_revision();
-        $params = array('theme'=>$this->name,'rev'=>$rev);
+        $params = ['theme' => $this->name, 'rev' => $rev];
         $params['type'] = $inhead ? 'head' : 'footer';
 
-        // Return early if there are no files to serve
+        // Return early if there are no files to serve.
         if (count($this->javascript_files($params['type'])) === 0) {
             return null;
         }
 
-        if (!empty($CFG->slasharguments) and $rev > 0) {
+        if (!empty($CFG->slasharguments) && $rev > 0) {
             $url = new moodle_url("/theme/javascript.php");
-            $url->set_slashargument('/'.$this->name.'/'.$rev.'/'.$params['type'], 'noparam', true);
+            $url->set_slashargument('/' . $this->name . '/' . $rev . '/' . $params['type'], 'noparam', true);
             return $url;
         } else {
             return new moodle_url('/theme/javascript.php', $params);
@@ -1470,21 +1479,24 @@ class theme_config {
             $type = 'javascripts';
         }
 
-        $js = array();
-        // find out wanted parent javascripts
+        $js = [];
+        // Find out wanted parent javascripts.
         $excludes = $this->resolve_excludes('parents_exclude_javascripts');
         if ($excludes !== true) {
-            foreach (array_reverse($this->parent_configs) as $parent_config) { // base first, the immediate parent last
+            foreach (array_reverse($this->parent_configs) as $parent_config) { // Base first, the immediate parent last.
                 $parent = $parent_config->name;
                 if (empty($parent_config->$type)) {
                     continue;
                 }
-                if (!empty($excludes[$parent]) and $excludes[$parent] === true) {
+                if (!empty($excludes[$parent]) && $excludes[$parent] === true) {
                     continue;
                 }
                 foreach ($parent_config->$type as $javascript) {
-                    if (!empty($excludes[$parent]) and is_array($excludes[$parent])
-                        and in_array($javascript, $excludes[$parent])) {
+                    if (
+                        !empty($excludes[$parent])
+                        && is_array($excludes[$parent])
+                        && in_array($javascript, $excludes[$parent])
+                    ) {
                         continue;
                     }
                     $javascriptfile = "$parent_config->dir/javascript/$javascript.js";
@@ -1495,7 +1507,7 @@ class theme_config {
             }
         }
 
-        // current theme javascripts
+        // Current theme javascripts.
         if (is_array($this->$type)) {
             foreach ($this->$type as $javascript) {
                 $javascriptfile = "$this->dir/javascript/$javascript.js";
@@ -1517,14 +1529,14 @@ class theme_config {
      */
     protected function resolve_excludes($variable, $default = null) {
         $setting = $default;
-        if (is_array($this->{$variable}) or $this->{$variable} === true) {
+        if (is_array($this->{$variable}) || $this->{$variable} === true) {
             $setting = $this->{$variable};
         } else {
-            foreach ($this->parent_configs as $parent_config) { // the immediate parent first, base last
+            foreach ($this->parent_configs as $parent_config) { // The immediate parent first, base last.
                 if (!isset($parent_config->{$variable})) {
                     continue;
                 }
-                if (is_array($parent_config->{$variable}) or $parent_config->{$variable} === true) {
+                if (is_array($parent_config->{$variable}) || $parent_config->{$variable} === true) {
                     $setting = $parent_config->{$variable};
                     break;
                 }
@@ -1543,7 +1555,7 @@ class theme_config {
         $jsfiles = $this->javascript_files($type);
         $js = '';
         foreach ($jsfiles as $jsfile) {
-            $js .= file_get_contents($jsfile)."\n";
+            $js .= file_get_contents($jsfile) . "\n";
         }
         return $js;
     }
@@ -1560,9 +1572,9 @@ class theme_config {
      * @return string The processed CSS.
      */
     public function post_process($css) {
-        // now resolve all image locations
+        // Now resolve all image locations.
         if (preg_match_all('/\[\[pix:([a-z0-9_]+\|)?([^\]]+)\]\]/', $css, $matches, PREG_SET_ORDER)) {
-            $replaced = array();
+            $replaced = [];
             foreach ($matches as $match) {
                 if (isset($replaced[$match[0]])) {
                     continue;
@@ -1571,7 +1583,7 @@ class theme_config {
                 $imagename = $match[2];
                 $component = rtrim($match[1], '|');
                 $imageurl = $this->image_url($imagename, $component)->out(false);
-                 // we do not need full url because the image.php is always in the same dir
+                // We do not need full url because the image.php is always in the same dir.
                 $imageurl = preg_replace('|^http.?://[^/]+|', '', $imageurl);
                 $css = str_replace($match[0], $imageurl, $css);
             }
@@ -1579,7 +1591,7 @@ class theme_config {
 
         // Now resolve all font locations.
         if (preg_match_all('/\[\[font:([a-z0-9_]+\|)?([^\]]+)\]\]/', $css, $matches, PREG_SET_ORDER)) {
-            $replaced = array();
+            $replaced = [];
             foreach ($matches as $match) {
                 if (isset($replaced[$match[0]])) {
                     continue;
@@ -1605,7 +1617,6 @@ class theme_config {
         $treeprocessor = $this->get_css_tree_post_processor();
         $needsparsing = !empty($treeprocessor) || !empty($this->rtlmode);
         if ($needsparsing) {
-
             // We might need more memory/time to do this, so let's play safe.
             raise_memory_limit(MEMORY_EXTRA);
             core_php_time_limit::raise(300);
@@ -1667,10 +1678,10 @@ class theme_config {
     public function image_url($imagename, $component) {
         global $CFG;
 
-        $params = array('theme'=>$this->name);
+        $params = ['theme' => $this->name];
         $svg = $this->use_svg_icons();
 
-        if (empty($component) or $component === 'moodle' or $component === 'core') {
+        if (empty($component) || $component === 'moodle' || $component === 'core') {
             $params['component'] = 'core';
         } else {
             $params['component'] = $component;
@@ -1684,12 +1695,12 @@ class theme_config {
         $params['image'] = $imagename;
 
         $url = new moodle_url("/theme/image.php");
-        if (!empty($CFG->slasharguments) and $rev > 0) {
-            $path = '/'.$params['theme'].'/'.$params['component'].'/'.$params['rev'].'/'.$params['image'];
+        if (!empty($CFG->slasharguments) && $rev > 0) {
+            $path = '/' . $params['theme'] . '/' . $params['component'] . '/' . $params['rev'] . '/' . $params['image'];
             if (!$svg) {
                 // We add a simple /_s to the start of the path.
                 // The underscore is used to ensure that it isn't a valid theme name.
-                $path = '/_s'.$path;
+                $path = '/_s' . $path;
             }
             $url->set_slashargument($path, 'noparam', true);
         } else {
@@ -1714,9 +1725,9 @@ class theme_config {
     public function font_url($font, $component) {
         global $CFG;
 
-        $params = array('theme'=>$this->name);
+        $params = ['theme' => $this->name];
 
-        if (empty($component) or $component === 'moodle' or $component === 'core') {
+        if (empty($component) || $component === 'moodle' || $component === 'core') {
             $params['component'] = 'core';
         } else {
             $params['component'] = $component;
@@ -1730,8 +1741,8 @@ class theme_config {
         $params['font'] = $font;
 
         $url = new moodle_url("/theme/font.php");
-        if (!empty($CFG->slasharguments) and $rev > 0) {
-            $path = '/'.$params['theme'].'/'.$params['component'].'/'.$params['rev'].'/'.$params['font'];
+        if (!empty($CFG->slasharguments) && $rev > 0) {
+            $path = '/' . $params['theme'] . '/' . $params['component'] . '/' . $params['rev'] . '/' . $params['font'];
             $url->set_slashargument($path, 'noparam', true);
         } else {
             $url->params($params);
@@ -1757,12 +1768,15 @@ class theme_config {
             return null;
         }
 
-        $component = 'theme_'.$this->name;
+        $component = 'theme_' . $this->name;
         $itemid = theme_get_revision();
         $filepath = $this->settings->$setting;
         $syscontext = context_system::instance();
 
-        $url = moodle_url::make_file_url("$CFG->wwwroot/pluginfile.php", "/$syscontext->id/$component/$filearea/$itemid".$filepath);
+        $url = moodle_url::make_file_url(
+            "$CFG->wwwroot/pluginfile.php",
+            "/$syscontext->id/$component/$filearea/$itemid" . $filepath,
+        );
 
         // Now this is tricky because the we can not hardcode http or https here, lets use the relative link.
         // Note: unfortunately moodle_url does not support //urls yet.
@@ -1786,13 +1800,13 @@ class theme_config {
         require_once("$CFG->libdir/filelib.php");
 
         $syscontext = context_system::instance();
-        $component = 'theme_'.$this->name;
+        $component = 'theme_' . $this->name;
 
         $revision = array_shift($args);
         if ($revision < 0) {
             $lifetime = 0;
         } else {
-            $lifetime = 60*60*24*60;
+            $lifetime = 60 * 60 * 24 * 60;
             // By default, theme files must be cache-able by both browsers and proxies.
             if (!array_key_exists('cacheability', $options)) {
                 $options['cacheability'] = 'public';
@@ -1836,11 +1850,11 @@ class theme_config {
             $svg = $this->use_svg_icons();
         }
 
-        if ($component === 'moodle' or $component === 'core' or empty($component)) {
+        if ($component === 'moodle' || $component === 'core' || empty($component)) {
             if ($imagefile = $this->image_exists("$this->dir/pix_core/$image", $svg)) {
                 return $imagefile;
             }
-            foreach (array_reverse($this->parent_configs) as $parent_config) { // base first, the immediate parent last
+            foreach (array_reverse($this->parent_configs) as $parent_config) { // Base first, the immediate parent last.
                 if ($imagefile = $this->image_exists("$parent_config->dir/pix_core/$image", $svg)) {
                     return $imagefile;
                 }
@@ -1852,26 +1866,24 @@ class theme_config {
                 return $imagefile;
             }
             return null;
-
-        } else if ($component === 'theme') { //exception
+        } else if ($component === 'theme') { // Exception.
             if ($image === 'favicon') {
                 return "$this->dir/pix/favicon.ico";
             }
             if ($imagefile = $this->image_exists("$this->dir/pix/$image", $svg)) {
                 return $imagefile;
             }
-            foreach (array_reverse($this->parent_configs) as $parent_config) { // base first, the immediate parent last
+            foreach (array_reverse($this->parent_configs) as $parent_config) { // Base first, the immediate parent last.
                 if ($imagefile = $this->image_exists("$parent_config->dir/pix/$image", $svg)) {
                     return $imagefile;
                 }
             }
             return null;
-
         } else {
             if (strpos($component, '_') === false) {
                 $component = "mod_{$component}";
             }
-            list($type, $plugin) = explode('_', $component, 2);
+            [$type, $plugin] = explode('_', $component, 2);
 
             // In Moodle 4.0 we introduced a new image format.
             // Support that image format here.
@@ -1923,7 +1935,7 @@ class theme_config {
     public function resolve_font_location($font, $component) {
         global $CFG;
 
-        if ($component === 'moodle' or $component === 'core' or empty($component)) {
+        if ($component === 'moodle' || $component === 'core' || empty($component)) {
             if (file_exists("$this->dir/fonts_core/$font")) {
                 return "$this->dir/fonts_core/$font";
             }
@@ -1939,7 +1951,6 @@ class theme_config {
                 return "$CFG->dirroot/lib/fonts/$font";
             }
             return null;
-
         } else if ($component === 'theme') { // Exception.
             if (file_exists("$this->dir/fonts/$font")) {
                 return "$this->dir/fonts/$font";
@@ -1950,12 +1961,11 @@ class theme_config {
                 }
             }
             return null;
-
         } else {
             if (strpos($component, '_') === false) {
-                $component = 'mod_'.$component;
+                $component = 'mod_' . $component;
             }
-            list($type, $plugin) = explode('_', $component, 2);
+            [$type, $plugin] = explode('_', $component, 2);
 
             if (file_exists("$this->dir/fonts_plugins/$type/$plugin/$font")) {
                 return "$this->dir/fonts_plugins/$type/$plugin/$font";
@@ -2054,13 +2064,13 @@ class theme_config {
     private static function image_exists($filepath, $svg = false) {
         if ($svg && file_exists("$filepath.svg")) {
             return "$filepath.svg";
-        } else  if (file_exists("$filepath.png")) {
+        } else if (file_exists("$filepath.png")) {
             return "$filepath.png";
         } else if (file_exists("$filepath.gif")) {
             return "$filepath.gif";
-        } else  if (file_exists("$filepath.jpg")) {
+        } else if (file_exists("$filepath.jpg")) {
             return "$filepath.jpg";
-        } else  if (file_exists("$filepath.jpeg")) {
+        } else if (file_exists("$filepath.jpeg")) {
             return "$filepath.jpeg";
         } else {
             return false;
@@ -2088,12 +2098,12 @@ class theme_config {
         $THEME->dir      = $dir;
         $THEME->settings = $settings;
 
-        global $CFG; // just in case somebody tries to use $CFG in theme config
+        global $CFG; // Just in case somebody tries to use $CFG in theme config.
         include("$THEME->dir/config.php");
 
-        // verify the theme configuration is OK
+        // Verify the theme configuration is OK.
         if (!is_array($THEME->parents)) {
-            // parents option is mandatory now
+            // Parents option is mandatory now.
             return null;
         } else {
             // We use $parentscheck to only check the direct parents (avoid infinite loop).
@@ -2123,16 +2133,14 @@ class theme_config {
 
         if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {
             $dir = "$CFG->dirroot/theme/$themename";
-
-        } else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {
+        } else if (!empty($CFG->themedir) && file_exists("$CFG->themedir/$themename/config.php")) {
             $dir = "$CFG->themedir/$themename";
-
         } else {
             return null;
         }
 
         if (file_exists("$dir/styles.php")) {
-            //legacy theme - needs to be upgraded - upgrade info is displayed on the admin settings page
+            // Legacy theme - needs to be upgraded - upgrade info is displayed on the admin settings page.
             return null;
         }
 
@@ -2158,10 +2166,10 @@ class theme_config {
     }
 
     /**
-     * Get the information from {@link $layouts} for this type of page.
+     * Get the information from {@see $layouts} for this type of page.
      *
      * @param string $pagelayout the the page layout name.
-     * @return array the appropriate part of {@link $layouts}.
+     * @return array the appropriate part of {@see $layouts}.
      */
     protected function layout_info_for_page($pagelayout) {
         if (array_key_exists($pagelayout, $this->layouts)) {
@@ -2176,7 +2184,7 @@ class theme_config {
      * Given the settings of this theme, and the page pagelayout, return the
      * full path of the page layout file to use.
      *
-     * Used by {@link core_renderer::header()}.
+     * Used by {@see core_renderer::header()}.
      *
      * @param string $pagelayout the the page layout name.
      * @return string Full path to the lyout file to use
@@ -2188,9 +2196,9 @@ class theme_config {
         $layoutfile = $layoutinfo['file'];
 
         if (array_key_exists('theme', $layoutinfo)) {
-            $themes = array($layoutinfo['theme']);
+            $themes = [$layoutinfo['theme']];
         } else {
-            $themes = array_merge(array($this->name),$this->parents);
+            $themes = array_merge([$this->name], $this->parents);
         }
 
         foreach ($themes as $theme) {
@@ -2218,7 +2226,7 @@ class theme_config {
         if (!empty($info['options'])) {
             return $info['options'];
         }
-        return array();
+        return [];
     }
 
     /**
@@ -2269,7 +2277,7 @@ class theme_config {
      * @return array internal region name => human readable name.
      */
     public function get_all_block_regions() {
-        $regions = array();
+        $regions = [];
         foreach ($this->layouts as $layoutinfo) {
             foreach ($layoutinfo['regions'] as $region) {
                 $regions[$region] = $this->get_region_name($region, $this->name);
@@ -2284,7 +2292,7 @@ class theme_config {
      * @return string
      */
     public function get_theme_name() {
-        return get_string('pluginname', 'theme_'.$this->name);
+        return get_string('pluginname', 'theme_' . $this->name);
     }
 
     /**
@@ -2327,7 +2335,6 @@ class theme_config {
         }
         return null;
     }
-
 }
 // Alias this class to the old name.
 // This file will be autoloaded by the legacyclasses autoload system.
diff --git a/lib/classes/output/theme_usage.php b/lib/classes/output/theme_usage.php
index 21d33dda046..19633dc8642 100644
--- a/lib/classes/output/theme_usage.php
+++ b/lib/classes/output/theme_usage.php
@@ -25,7 +25,6 @@ namespace core\output;
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class theme_usage {
-
     /** @var string The theme usage type for users. */
     public const THEME_USAGE_TYPE_USER = 'user';
 
@@ -61,7 +60,6 @@ class theme_usage {
         $isused = $cache->get($themename);
 
         if ($isused === false) {
-
             $sqlunions = [];
 
             // For each context, check if the config is enabled and there is at least one use.
@@ -119,7 +117,6 @@ class theme_usage {
             // Cache the result so we don't have to keep checking for this theme.
             $cache->set($themename, $isused);
             return $isused;
-
         } else {
             return $isused;
         }
diff --git a/lib/classes/output/url_rewriter.php b/lib/classes/output/url_rewriter.php
index eacd434ed2f..5cc5270d6a2 100644
--- a/lib/classes/output/url_rewriter.php
+++ b/lib/classes/output/url_rewriter.php
@@ -25,8 +25,6 @@
 
 namespace core\output;
 
-defined('MOODLE_INTERNAL') || die();
-
 /**
  * URL rewriter interface
  *
@@ -36,7 +34,6 @@ defined('MOODLE_INTERNAL') || die();
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 interface url_rewriter {
-
     /**
      * Rewrite moodle_urls into another form.
      *
@@ -52,7 +49,4 @@ interface url_rewriter {
      * @return void
      */
     public static function html_head_setup();
-
-
 }
-
diff --git a/lib/classes/output/url_select.php b/lib/classes/output/url_select.php
index 0f043fa0815..3068f443ae9 100644
--- a/lib/classes/output/url_select.php
+++ b/lib/classes/output/url_select.php
@@ -36,62 +36,62 @@ class url_select implements renderable, templatable {
      *         array(array('Odd'=>array(1=>'One', 3=>'Three)), array('Even'=>array(2=>'Two')))
      *         array(1=>'One', '--1uniquekey'=>array('More'=>array(2=>'Two', 3=>'Three')))
      */
-    var $urls;
+    public $urls;
 
     /**
      * @var string Selected option
      */
-    var $selected;
+    public $selected;
 
     /**
      * @var array Nothing selected
      */
-    var $nothing;
+    public $nothing;
 
     /**
      * @var array Extra select field attributes
      */
-    var $attributes = array();
+    public $attributes = [];
 
     /**
      * @var string Button label
      */
-    var $label = '';
+    public $label = '';
 
     /**
      * @var array Button label's attributes
      */
-    var $labelattributes = array();
+    public $labelattributes = [];
 
     /**
      * @var string Wrapping div class
      */
-    var $class = 'urlselect';
+    public $class = 'urlselect';
 
     /**
      * @var bool True if button disabled, false if normal
      */
-    var $disabled = false;
+    public $disabled = false;
 
     /**
      * @var string Button tooltip
      */
-    var $tooltip = null;
+    public $tooltip = null;
 
     /**
      * @var string Form id
      */
-    var $formid = null;
+    public $formid = null;
 
     /**
      * @var help_icon The help icon for this element.
      */
-    var $helpicon = null;
+    public $helpicon = null;
 
     /**
      * @var string If set, makes button visible with given name for button
      */
-    var $showbutton = null;
+    public $showbutton = null;
 
     /**
      * Constructor
@@ -102,7 +102,7 @@ class url_select implements renderable, templatable {
      * @param string $showbutton Set to text of button if it should be visible
      *   or null if it should be hidden (hidden version always has text 'go')
      */
-    public function __construct(array $urls, $selected = '', $nothing = array('' => 'choosedots'), $formid = null, $showbutton = null) {
+    public function __construct(array $urls, $selected = '', $nothing = ['' => 'choosedots'], $formid = null, $showbutton = null) {
         $this->urls       = $urls;
         $this->selected   = $selected;
         $this->nothing    = $nothing;
@@ -135,7 +135,7 @@ class url_select implements renderable, templatable {
      * @param string $label
      * @param array $attributes (optional)
      */
-    public function set_label($label, $attributes = array()) {
+    public function set_label($label, $attributes = []) {
         $this->label = $label;
         $this->labelattributes = $attributes;
     }
@@ -149,12 +149,11 @@ class url_select implements renderable, templatable {
     protected function clean_url($value) {
         global $CFG;
 
+        // phpcs:ignore Generic.CodeAnalysis.EmptyStatement.DetectedIf
         if (empty($value)) {
             // Nothing.
-
         } else if (strpos($value, $CFG->wwwroot . '/') === 0) {
             $value = str_replace($CFG->wwwroot, '', $value);
-
         } else if (strpos($value, '/') !== 0) {
             debugging("Invalid url_select urls parameter: url '$value' is not local relative url!", DEBUG_DEVELOPER);
         }
@@ -181,7 +180,7 @@ class url_select implements renderable, templatable {
                         $flattened[$groupname] = [
                             'name' => $groupname,
                             'isgroup' => true,
-                            'options' => []
+                            'options' => [],
                         ];
                     }
                     foreach ($optoptions as $optvalue => $optoption) {
@@ -193,7 +192,6 @@ class url_select implements renderable, templatable {
                         ];
                     }
                 }
-
             } else {
                 $cleanedvalue = $this->clean_url($value);
                 $flattened[$cleanedvalue] = [
@@ -208,7 +206,7 @@ class url_select implements renderable, templatable {
             $value = key($nothing);
             $name = reset($nothing);
             $flattened = [
-                    $value => ['name' => $name, 'value' => $value, 'selected' => $this->selected == $value]
+                    $value => ['name' => $name, 'value' => $value, 'selected' => $this->selected == $value],
                 ] + $flattened;
         }
 
diff --git a/lib/classes/output/user_picture.php b/lib/classes/output/user_picture.php
index a7947b6430c..8da6537c581 100644
--- a/lib/classes/output/user_picture.php
+++ b/lib/classes/output/user_picture.php
@@ -17,6 +17,7 @@
 namespace core\output;
 
 use core\context\user as context_user;
+use core\exception\coding_exception;
 use moodle_page;
 use moodle_url;
 use stdClass;
@@ -40,7 +41,7 @@ class user_picture implements renderable {
     /**
      * @var int The course id. Used when constructing the link to the user's
      * profile, page course id used if not specified.
-    */
+     */
     public $courseid;
 
     /**
@@ -99,20 +100,28 @@ class user_picture implements renderable {
             throw new coding_exception('User id is required when printing user avatar image.');
         }
 
-        // only touch the DB if we are missing data and complain loudly...
+        // Only touch the DB if we are missing data and complain loudly...
         $needrec = false;
         foreach (\core_user\fields::get_picture_fields() as $field) {
             if (!property_exists($user, $field)) {
                 $needrec = true;
-                debugging('Missing '.$field.' property in $user object, this is a performance problem that needs to be fixed by a developer. '
-                    .'Please use the \core_user\fields API to get the full list of required fields.', DEBUG_DEVELOPER);
+                debugging(
+                    "Missing {$field} property in {$user} object, "
+                        . "this is a performance problem that needs to be fixed by a developer. "
+                        . 'Please use the \core_user\fields API to get the full list of required fields.',
+                    DEBUG_DEVELOPER,
+                );
                 break;
             }
         }
 
         if ($needrec) {
-            $this->user = $DB->get_record('user', array('id' => $user->id),
-                implode(',', \core_user\fields::get_picture_fields()), MUST_EXIST);
+            $this->user = $DB->get_record(
+                'user',
+                ['id' => $user->id],
+                implode(',', \core_user\fields::get_picture_fields()),
+                MUST_EXIST
+            );
         } else {
             $this->user = clone($user);
         }
@@ -126,14 +135,20 @@ class user_picture implements renderable {
      * id of the result record. Please note it has to be converted back to id before rendering.
      *
      * @param string $tableprefix name of database table prefix in query
-     * @param array $extrafields extra fields to be included in result (do not include TEXT columns because it would break SELECT DISTINCT in MSSQL and ORACLE)
+     * @param null|array $extrafields extra fields to be included in result
+     *      Do not include TEXT columns because it would break SELECT DISTINCT in MSSQL and ORACLE.
      * @param string $idalias alias of id field
      * @param string $fieldprefix prefix to add to all columns in their aliases, does not apply to 'id'
      * @return string
      * @deprecated since Moodle 3.11 MDL-45242
      * @see \core_user\fields
      */
-    public static function fields($tableprefix = '', array $extrafields = NULL, $idalias = 'id', $fieldprefix = '') {
+    public static function fields(
+        $tableprefix = '',
+        ?array $extrafields = null,
+        $idalias = 'id',
+        $fieldprefix = '',
+    ) {
         debugging('user_picture::fields() is deprecated. Please use the \core_user\fields API instead.', DEBUG_DEVELOPER);
         $userfields = \core_user\fields::for_userpic();
         if ($extrafields) {
@@ -152,17 +167,21 @@ class user_picture implements renderable {
     /**
      * Extract the aliased user fields from a given record
      *
-     * Given a record that was previously obtained using {@link self::fields()} with aliases,
+     * Given a record that was previously obtained using {@see self::fields()} with aliases,
      * this method extracts user related unaliased fields.
      *
      * @param stdClass $record containing user picture fields
-     * @param array $extrafields extra fields included in the $record
+     * @param null|array $extrafields extra fields included in the $record
      * @param string $idalias alias of the id field
      * @param string $fieldprefix prefix added to all columns in their aliases, does not apply to 'id'
      * @return stdClass object with unaliased user fields
      */
-    public static function unalias(stdClass $record, array $extrafields = null, $idalias = 'id', $fieldprefix = '') {
-
+    public static function unalias(
+        stdClass $record,
+        ?array $extrafields = null,
+        $idalias = 'id',
+        $fieldprefix = '',
+    ) {
         if (empty($idalias)) {
             $idalias = 'id';
         }
@@ -175,18 +194,18 @@ class user_picture implements renderable {
                     $return->id = $record->{$idalias};
                 }
             } else {
-                if (property_exists($record, $fieldprefix.$field)) {
-                    $return->{$field} = $record->{$fieldprefix.$field};
+                if (property_exists($record, $fieldprefix . $field)) {
+                    $return->{$field} = $record->{$fieldprefix . $field};
                 }
             }
         }
-        // add extra fields if not already there
+        // Add extra fields if not already there.
         if ($extrafields) {
             foreach ($extrafields as $e) {
-                if ($e === 'id' or property_exists($return, $e)) {
+                if ($e === 'id' || property_exists($return, $e)) {
                     continue;
                 }
-                $return->{$e} = $record->{$fieldprefix.$e};
+                $return->{$e} = $record->{$fieldprefix . $e};
             }
         }
 
@@ -200,10 +219,13 @@ class user_picture implements renderable {
      * if requests are made for non-existent files etc.
      *
      * @param moodle_page $page
-     * @param renderer_base $renderer
+     * @param null|renderer_base $renderer
      * @return moodle_url
      */
-    public function get_url(moodle_page $page, renderer_base $renderer = null) {
+    public function get_url(
+        moodle_page $page,
+        ?renderer_base $renderer = null,
+    ) {
         global $CFG;
 
         if (is_null($renderer)) {
@@ -215,7 +237,7 @@ class user_picture implements renderable {
         if (empty($this->size)) {
             $filename = 'f2';
             $size = 35;
-        } else if ($this->size === true or $this->size == 1) {
+        } else if ($this->size === true || $this->size == 1) {
             $filename = 'f1';
             $size = 100;
         } else if ($this->size > 100) {
@@ -229,10 +251,12 @@ class user_picture implements renderable {
             $size = (int)$this->size;
         }
 
-        $defaulturl = $renderer->image_url('u/'.$filename); // default image
+        $defaulturl = $renderer->image_url('u/' . $filename); // Default image.
 
-        if ((!empty($CFG->forcelogin) and !isloggedin()) ||
-            (!empty($CFG->forceloginforprofileimage) && (!isloggedin() || isguestuser()))) {
+        if (
+            (!empty($CFG->forcelogin) && !isloggedin()) ||
+            (!empty($CFG->forceloginforprofileimage) && (!isloggedin() || isguestuser()))
+        ) {
             // Protect images if login required and not logged in;
             // also if login is required for profile images and is not logged in or guest
             // do not use require_login() because it is expensive and not suitable here anyway.
@@ -240,7 +264,7 @@ class user_picture implements renderable {
         }
 
         // First try to detect deleted users - but do not read from database for performance reasons!
-        if (!empty($this->user->deleted) or strpos($this->user->email, '@') === false) {
+        if (!empty($this->user->deleted) || !str_contains($this->user->email, '@')) {
             // All deleted users should have email replaced by md5 hash,
             // all active users are expected to have valid email.
             return $defaulturl;
@@ -265,27 +289,35 @@ class user_picture implements renderable {
                 // in the circumstance that the profile picture is not available
                 // when the user actually requests it they still get the profile
                 // picture for the correct theme.
-                $path .= $page->theme->name.'/';
+                $path .= $page->theme->name . '/';
             }
             // Set the image URL to the URL for the uploaded file and return.
             $url = moodle_url::make_pluginfile_url(
-                $contextid, 'user', 'icon', null, $path, $filename, false, $this->includetoken);
+                $contextid,
+                'user',
+                'icon',
+                null,
+                $path,
+                $filename,
+                false,
+                $this->includetoken
+            );
             $url->param('rev', $this->user->picture);
             return $url;
         }
 
-        if ($this->user->picture == 0 and !empty($CFG->enablegravatar)) {
-            // Normalise the size variable to acceptable bounds
+        if ($this->user->picture == 0 && !empty($CFG->enablegravatar)) {
+            // Normalise the size variable to acceptable bounds.
             if ($size < 1 || $size > 512) {
                 $size = 35;
             }
-            // Hash the users email address
+            // Hash the users email address.
             $md5 = md5(strtolower(trim($this->user->email)));
             // Build a gravatar URL with what we know.
 
-            // Find the best default image URL we can (MDL-35669)
+            // Find the best default image URL we can (MDL-35669).
             if (empty($CFG->gravatardefaulturl)) {
-                $absoluteimagepath = $page->theme->resolve_image_location('u/'.$filename, 'core');
+                $absoluteimagepath = $page->theme->resolve_image_location('u/' . $filename, 'core');
                 if (strpos($absoluteimagepath, $CFG->dirroot) === 0) {
                     $gravatardefault = $CFG->wwwroot . substr($absoluteimagepath, strlen($CFG->dirroot));
                 } else {
@@ -298,9 +330,9 @@ class user_picture implements renderable {
             // If the currently requested page is https then we'll return an
             // https gravatar page.
             if (is_https()) {
-                return new moodle_url("https://secure.gravatar.com/avatar/{$md5}", array('s' => $size, 'd' => $gravatardefault));
+                return new moodle_url("https://secure.gravatar.com/avatar/{$md5}", ['s' => $size, 'd' => $gravatardefault]);
             } else {
-                return new moodle_url("http://www.gravatar.com/avatar/{$md5}", array('s' => $size, 'd' => $gravatardefault));
+                return new moodle_url("http://www.gravatar.com/avatar/{$md5}", ['s' => $size, 'd' => $gravatardefault]);
             }
         }
 
diff --git a/lib/classes/output/xhtml_container_stack.php b/lib/classes/output/xhtml_container_stack.php
index 64e7192397b..ccb52ac5511 100644
--- a/lib/classes/output/xhtml_container_stack.php
+++ b/lib/classes/output/xhtml_container_stack.php
@@ -36,16 +36,16 @@ class xhtml_container_stack {
     /**
      * @var array Stores the list of open containers.
      */
-    protected $opencontainers = array();
+    protected $opencontainers = [];
 
     /**
      * @var array In developer debug mode, stores a stack trace of all opens and
      * closes, so we can output helpful error messages when there is a mismatch.
      */
-    protected $log = array();
+    protected $log = [];
 
     /**
-     * @var boolean Store whether we are developer debug mode. We need this in
+     * @var bool Store whether we are developer debug mode. We need this in
      * several places including in the destructor where we may not have access to $CFG.
      */
     protected $isdebugging;
@@ -61,7 +61,7 @@ class xhtml_container_stack {
     /**
      * Push the close HTML for a recently opened container onto the stack.
      *
-     * @param string $type The type of container. This is checked when {@link pop()}
+     * @param string $type The type of container. This is checked when {@see pop()}
      *      is called and must match, otherwise a developer debug warning is output.
      * @param string $closehtml The HTML required to close the container.
      */
diff --git a/lib/outputactions.php b/lib/outputactions.php
index 0fdca282e68..b7c551871da 100644
--- a/lib/outputactions.php
+++ b/lib/outputactions.php
@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+defined('MOODLE_INTERNAL') || die();
+
 // This file is deprecated, but it should never have been manually included by anything outside of lib/outputlib.php.
 // Throwing an exception here should be fine because removing the manual inclusion should have no impact.
 throw new \core\exception\coding_exception(
diff --git a/lib/outputcomponents.php b/lib/outputcomponents.php
index 0fdca282e68..b7c551871da 100644
--- a/lib/outputcomponents.php
+++ b/lib/outputcomponents.php
@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+defined('MOODLE_INTERNAL') || die();
+
 // This file is deprecated, but it should never have been manually included by anything outside of lib/outputlib.php.
 // Throwing an exception here should be fine because removing the manual inclusion should have no impact.
 throw new \core\exception\coding_exception(
diff --git a/lib/outputfactories.php b/lib/outputfactories.php
index 0fdca282e68..b7c551871da 100644
--- a/lib/outputfactories.php
+++ b/lib/outputfactories.php
@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+defined('MOODLE_INTERNAL') || die();
+
 // This file is deprecated, but it should never have been manually included by anything outside of lib/outputlib.php.
 // Throwing an exception here should be fine because removing the manual inclusion should have no impact.
 throw new \core\exception\coding_exception(
diff --git a/lib/outputfragmentrequirementslib.php b/lib/outputfragmentrequirementslib.php
index 2b6fa039198..b7c551871da 100644
--- a/lib/outputfragmentrequirementslib.php
+++ b/lib/outputfragmentrequirementslib.php
@@ -14,7 +14,9 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-// This file is deprecated, but it should never have been manually included by anything outside of lib/pagelib.php.
+defined('MOODLE_INTERNAL') || die();
+
+// This file is deprecated, but it should never have been manually included by anything outside of lib/outputlib.php.
 // Throwing an exception here should be fine because removing the manual inclusion should have no impact.
 throw new \core\exception\coding_exception(
     'This file should not be manually included by any component.',
diff --git a/lib/outputlib.php b/lib/outputlib.php
index 4dbf86e0b3b..ef3dd636d88 100644
--- a/lib/outputlib.php
+++ b/lib/outputlib.php
@@ -59,7 +59,6 @@ function theme_get_revision() {
         } else {
             return $CFG->themerev;
         }
-
     } else {
         return -1;
     }
@@ -99,11 +98,11 @@ function theme_get_next_revision() {
     global $CFG;
 
     $next = time();
-    if (isset($CFG->themerev) and $next <= $CFG->themerev and $CFG->themerev - $next < 60*60) {
+    if (isset($CFG->themerev) && ($next <= $CFG->themerev) && (($CFG->themerev - $next) < 60 * 60)) {
         // This resolves problems when reset is requested repeatedly within 1s,
         // the < 1h condition prevents accidental switching to future dates
         // because we might not recover from it.
-        $next = $CFG->themerev+1;
+        $next = $CFG->themerev + 1;
     }
 
     return $next;
@@ -120,7 +119,7 @@ function theme_get_next_sub_revision_for_theme($themename) {
 
     $next = time();
     $current = theme_get_sub_revision_for_theme($themename);
-    if ($next <= $current and $current - $next < 60 * 60) {
+    if ($next <= $current && $current - $next < 60 * 60) {
         // This resolves problems when reset is requested repeatedly within 1s,
         // the < 1h condition prevents accidental switching to future dates
         // because we might not recover from it.
@@ -160,7 +159,7 @@ function theme_get_config_file_path($themename) {
 
     if (file_exists("{$CFG->dirroot}/theme/{$themename}/config.php")) {
         return "{$CFG->dirroot}/theme/{$themename}/config.php";
-    } else if (!empty($CFG->themedir) and file_exists("{$CFG->themedir}/{$themename}/config.php")) {
+    } else if (!empty($CFG->themedir) && file_exists("{$CFG->themedir}/{$themename}/config.php")) {
         return "{$CFG->themedir}/{$themename}/config.php";
     } else {
         return null;
@@ -191,8 +190,12 @@ function theme_get_css_filename($themename, $globalrevision, $themerevision, $di
  * @param bool           $cache        Should the generated files be stored in local cache.
  * @return array         The built theme content in a multi-dimensional array of name => direction => content
  */
-function theme_build_css_for_themes($themeconfigs = [], $directions = ['rtl', 'ltr'],
-        $cache = true, $mtraceprogress = false): array {
+function theme_build_css_for_themes(
+    $themeconfigs = [],
+    $directions = ['rtl', 'ltr'],
+    $cache = true,
+    $mtraceprogress = false
+): array {
     global $CFG;
 
     if (empty($themeconfigs)) {
@@ -344,7 +347,7 @@ function template_reset_all_caches() {
     global $CFG;
 
     $next = time();
-    if (isset($CFG->templaterev) and $next <= $CFG->templaterev and $CFG->templaterev - $next < 60 * 60) {
+    if (isset($CFG->templaterev) && $next <= $CFG->templaterev && $CFG->templaterev - $next < 60 * 60) {
         // This resolves problems when reset is requested repeatedly within 1s,
         // the < 1h condition prevents accidental switching to future dates
         // because we might not recover from it.
@@ -361,11 +364,11 @@ function js_reset_all_caches() {
     global $CFG;
 
     $next = time();
-    if (isset($CFG->jsrev) and $next <= $CFG->jsrev and $CFG->jsrev - $next < 60*60) {
+    if (isset($CFG->jsrev) && $next <= $CFG->jsrev && $CFG->jsrev - $next < 60 * 60) {
         // This resolves problems when reset is requested repeatedly within 1s,
         // the < 1h condition prevents accidental switching to future dates
         // because we might not recover from it.
-        $next = $CFG->jsrev+1;
+        $next = $CFG->jsrev + 1;
     }
 
     set_config('jsrev', $next);
diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index 0fdca282e68..b7c551871da 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+defined('MOODLE_INTERNAL') || die();
+
 // This file is deprecated, but it should never have been manually included by anything outside of lib/outputlib.php.
 // Throwing an exception here should be fine because removing the manual inclusion should have no impact.
 throw new \core\exception\coding_exception(
diff --git a/lib/outputrequirementslib.php b/lib/outputrequirementslib.php
index 0fdca282e68..b7c551871da 100644
--- a/lib/outputrequirementslib.php
+++ b/lib/outputrequirementslib.php
@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+defined('MOODLE_INTERNAL') || die();
+
 // This file is deprecated, but it should never have been manually included by anything outside of lib/outputlib.php.
 // Throwing an exception here should be fine because removing the manual inclusion should have no impact.
 throw new \core\exception\coding_exception(
diff --git a/lib/table/classes/base_export_format.php b/lib/table/classes/base_export_format.php
index 22b29fd89db..35653e4c444 100644
--- a/lib/table/classes/base_export_format.php
+++ b/lib/table/classes/base_export_format.php
@@ -27,25 +27,23 @@ require_once("{$CFG->libdir}/tablelib.php");
 /**
  * The table base export format.
  *
- * @package   moodlecore
+ * @package   core_table
  * @copyright 1999 onwards Martin Dougiamas  {@link http://moodle.com}
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class base_export_format {
     /**
-     * @var flexible_table or child class reference pointing to table class
-     * object from which to export data.
+     * @var flexible_table or child class reference pointing to table class object from which to export data.
      */
-    var $table;
+    public $table;
 
     /**
-     * @var bool output started. Keeps track of whether any output has been
-     * started yet.
+     * @var bool output started. Keeps track of whether any output has been started yet.
      */
-    var $documentstarted = false;
+    public $documentstarted = false;
 
     /**
-     * Constructor
+     * Constructor.
      *
      * @param flexible_table $table
      */
@@ -53,39 +51,37 @@ class base_export_format {
         $this->table =& $table;
     }
 
-    /**
-     * Old syntax of class constructor. Deprecated in PHP7.
-     *
-     * @deprecated since Moodle 3.1
-     */
-    public function table_default_export_format_parent(&$table) {
-        debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
-        self::__construct($table);
-    }
-
-    function set_table(&$table) {
+    public function set_table(&$table) {
         $this->table =& $table;
     }
 
-    function add_data($row) {
+    public function add_data($row) {
         return false;
     }
 
-    function add_seperator() {
+    public function add_seperator() {
         return false;
     }
 
-    function document_started() {
+    public function document_started() {
         return $this->documentstarted;
     }
+
     /**
+     * Format the text.
+     *
      * Given text in a variety of format codings, this function returns
      * the text as safe HTML or as plain text dependent on what is appropriate
      * for the download format. The default removes all tags.
+     *
+     * @param string $text
+     * @param int $format
+     * @param null|array $options
+     * @param null|int $courseid
      */
-    function format_text($text, $format=FORMAT_MOODLE, $options=NULL, $courseid=NULL) {
-        //use some whitespace to indicate where there was some line spacing.
-        $text = str_replace(array('</p>', "\n", "\r"), '   ', $text);
+    public function format_text($text, $format = FORMAT_MOODLE, $options = null, $courseid = null) {
+        // Use some whitespace to indicate where there was some line spacing.
+        $text = str_replace(['</p>', "\n", "\r"], '   ', $text);
         return html_entity_decode(strip_tags($text), ENT_COMPAT);
     }
 
diff --git a/lib/table/classes/dataformat_export_format.php b/lib/table/classes/dataformat_export_format.php
index 4d2922728cf..fcc84a4a8b5 100644
--- a/lib/table/classes/dataformat_export_format.php
+++ b/lib/table/classes/dataformat_export_format.php
@@ -29,7 +29,7 @@ use core\dataformat;
 /**
  * Dataformat exporter
  *
- * @package    core
+ * @package    core_table
  * @subpackage tablelib
  * @copyright  2016 Brendan Heywood (brendan@catalyst-au.net)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
diff --git a/lib/table/classes/flexible_table.php b/lib/table/classes/flexible_table.php
index 3950b5770ce..65ba85b5013 100644
--- a/lib/table/classes/flexible_table.php
+++ b/lib/table/classes/flexible_table.php
@@ -31,6 +31,8 @@ global $CFG;
 
 require_once("{$CFG->libdir}/tablelib.php");
 
+// phpcs:disable moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
+
 /**
  * Flexible table implementation.
  *
@@ -39,10 +41,9 @@ require_once("{$CFG->libdir}/tablelib.php");
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class flexible_table {
-
-    var $uniqueid        = NULL;
-    var $attributes      = array();
-    var $headers         = array();
+    public $uniqueid        = null;
+    public $attributes      = [];
+    public $headers         = [];
 
     /**
      * @var string A column which should be considered as a header column.
@@ -52,23 +53,23 @@ class flexible_table {
     /**
      * @var string For create header with help icon.
      */
-    private $helpforheaders = array();
-    var $columns         = array();
-    var $column_style    = array();
-    var $column_class    = array();
-    var $column_suppress = array();
-    var $column_nosort   = array('userpic');
-    private $column_textsort = array();
+    private $helpforheaders = [];
+    public $columns         = [];
+    public $column_style    = [];
+    public $column_class    = [];
+    public $column_suppress = [];
+    public $column_nosort   = ['userpic'];
+    private $column_textsort = [];
 
     /**
      * @var array The sticky attribute of each table column.
      */
     protected $columnsticky = [];
 
-    /** @var boolean Stores if setup has already been called on this flixible table. */
-    var $setup           = false;
-    var $baseurl         = NULL;
-    var $request         = array();
+    /** @var bool Stores if setup has already been called on this flixible table. */
+    public $setup           = false;
+    public $baseurl         = null;
+    public $request         = [];
 
     /** @var string[] Columns that are expected to contain a users fullname.  */
     protected $userfullnamecolumns = ['fullname'];
@@ -80,8 +81,8 @@ class flexible_table {
      * @var bool Whether or not to store table properties in the user_preferences table.
      */
     private $persistent = false;
-    var $is_collapsible = false;
-    var $is_sortable    = false;
+    public $is_collapsible = false;
+    public $is_sortable    = false;
 
     /**
      * @var array The fields to sort.
@@ -94,24 +95,24 @@ class flexible_table {
     /** @var string The manually set last name initial preference */
     protected $ilast;
 
-    var $use_pages      = false;
-    var $use_initials   = false;
+    public $use_pages      = false;
+    public $use_initials   = false;
 
-    var $maxsortkeys = 2;
-    var $pagesize    = 30;
-    var $currpage    = 0;
-    var $totalrows   = 0;
-    var $currentrow  = 0;
-    var $sort_default_column = NULL;
-    var $sort_default_order  = SORT_ASC;
+    public $maxsortkeys = 2;
+    public $pagesize    = 30;
+    public $currpage    = 0;
+    public $totalrows   = 0;
+    public $currentrow  = 0;
+    public $sort_default_column = null;
+    public $sort_default_order  = SORT_ASC;
 
-    /** @var integer The defeult per page size for the table. */
+    /** @var int The defeult per page size for the table. */
     private $defaultperpage = 30;
 
     /**
-     * Array of positions in which to display download controls.
+     * @var array Array of positions in which to display download controls.
      */
-    var $showdownloadbuttonsat= array(TABLE_P_TOP);
+    public $showdownloadbuttonsat = [TABLE_P_TOP];
 
     /**
      * @var string Key of field returned by db query that is the id field of the
@@ -124,26 +125,26 @@ class flexible_table {
      * html table with paging. Property set by is_downloading which typically
      * passes in cleaned data from $
      */
-    var $download  = '';
+    public $download  = '';
 
     /**
      * @var bool whether data is downloadable from table. Determines whether
      * to display download buttons. Set by method downloadable().
      */
-    var $downloadable = false;
+    public $downloadable = false;
 
     /**
      * @var bool Has start output been called yet?
      */
-    var $started_output = false;
+    public $started_output = false;
 
     /** @var dataformat_export_format */
-    var $exportclass = null;
+    public $exportclass = null;
 
     /**
      * @var array For storing user-customised table properties in the user_preferences db table.
      */
-    private $prefs = array();
+    private $prefs = [];
 
     /** @var string $sheettitle */
     protected $sheettitle;
@@ -178,9 +179,9 @@ class flexible_table {
      * @param string $uniqueid all tables have to have a unique id, this is used
      *      as a key when storing table properties like sort order in the session.
      */
-    function __construct($uniqueid) {
+    public function __construct($uniqueid) {
         $this->uniqueid = $uniqueid;
-        $this->request  = array(
+        $this->request  = [
             TABLE_VAR_SORT   => 'tsort',
             TABLE_VAR_HIDE   => 'thide',
             TABLE_VAR_SHOW   => 'tshow',
@@ -189,7 +190,7 @@ class flexible_table {
             TABLE_VAR_PAGE   => 'page',
             TABLE_VAR_RESET  => 'treset',
             TABLE_VAR_DIR    => 'tdir',
-        );
+        ];
     }
 
     /**
@@ -205,8 +206,8 @@ class flexible_table {
      * @param string $sheettitle title for downloaded data.
      * @return string download dataformat type.
      */
-    function is_downloading($download = null, $filename='', $sheettitle='') {
-        if ($download!==null) {
+    public function is_downloading($download = null, $filename = '', $sheettitle = '') {
+        if ($download !== null) {
             $this->sheettitle = $sheettitle;
             $this->is_downloadable(true);
             $this->download = $download;
@@ -221,7 +222,7 @@ class flexible_table {
      * @param dataformat_export_format $exportclass (optional) if passed, set the table to use this export class.
      * @return dataformat_export_format the export class in use (after any set).
      */
-    function export_class_instance($exportclass = null) {
+    public function export_class_instance($exportclass = null) {
         if (!is_null($exportclass)) {
             $this->started_output = true;
             $this->exportclass = $exportclass;
@@ -244,7 +245,7 @@ class flexible_table {
      * current state of table.
      * @return bool whether table data is set to be downloadable.
      */
-    function is_downloadable($downloadable = null) {
+    public function is_downloadable($downloadable = null) {
         if ($downloadable !== null) {
             $this->downloadable = $downloadable;
         }
@@ -271,7 +272,7 @@ class flexible_table {
      * @param array $showat array of postions in which to show download buttons.
      * Containing TABLE_P_TOP and/or TABLE_P_BOTTOM
      */
-    function show_download_buttons_at($showat) {
+    public function show_download_buttons_at($showat) {
         $this->showdownloadbuttonsat = $showat;
     }
 
@@ -283,7 +284,7 @@ class flexible_table {
      * @param int $defaultorder
      * @return void
      */
-    function sortable($bool, $defaultcolumn = NULL, $defaultorder = SORT_ASC) {
+    public function sortable($bool, $defaultcolumn = null, $defaultorder = SORT_ASC) {
         $this->is_sortable = $bool;
         $this->sort_default_column = $defaultcolumn;
         $this->sort_default_order  = $defaultorder;
@@ -295,7 +296,7 @@ class flexible_table {
      * with real columns. See MDL-40481 for an example.
      * @param string column name
      */
-    function text_sorting($column) {
+    public function text_sorting($column) {
         $this->column_textsort[] = $column;
     }
 
@@ -303,7 +304,7 @@ class flexible_table {
      * Do not sort using this column
      * @param string column name
      */
-    function no_sorting($column) {
+    public function no_sorting($column) {
         $this->column_nosort[] = $column;
     }
 
@@ -312,7 +313,7 @@ class flexible_table {
      * @param string column name, null means table
      * @return bool
      */
-    function is_sortable($column = null) {
+    public function is_sortable($column = null) {
         if (empty($column)) {
             return $this->is_sortable;
         }
@@ -327,7 +328,7 @@ class flexible_table {
      * @param bool $bool
      * @return void
      */
-    function collapsible($bool) {
+    public function collapsible($bool) {
         $this->is_collapsible = $bool;
     }
 
@@ -336,7 +337,7 @@ class flexible_table {
      * @param bool $bool
      * @return void
      */
-    function pageable($bool) {
+    public function pageable($bool) {
         $this->use_pages = $bool;
     }
 
@@ -345,7 +346,7 @@ class flexible_table {
      * @param bool $bool
      * @return void
      */
-    function initialbars($bool) {
+    public function initialbars($bool) {
         $this->use_initials = $bool;
     }
 
@@ -356,7 +357,7 @@ class flexible_table {
      * @param int $total
      * @return void
      */
-    function pagesize($perpage, $total) {
+    public function pagesize($perpage, $total) {
         $this->pagesize  = $perpage;
         $this->totalrows = $total;
         $this->use_pages = true;
@@ -368,7 +369,7 @@ class flexible_table {
      * @param array $variables
      * @return void
      */
-    function set_control_variables($variables) {
+    public function set_control_variables($variables) {
         foreach ($variables as $what => $variable) {
             if (isset($this->request[$what])) {
                 $this->request[$what] = $variable;
@@ -382,7 +383,7 @@ class flexible_table {
      * @param mixed $value
      * @return void
      */
-    function set_attribute($attribute, $value) {
+    public function set_attribute($attribute, $value) {
         $this->attributes[$attribute] = $value;
     }
 
@@ -395,7 +396,7 @@ class flexible_table {
      * for their first attempt.
      * @param int $column the index of a column.
      */
-    function column_suppress($column) {
+    public function column_suppress($column) {
         if (isset($this->column_suppress[$column])) {
             $this->column_suppress[$column] = true;
         }
@@ -407,9 +408,9 @@ class flexible_table {
      * @param string $classname
      * @return void
      */
-    function column_class($column, $classname) {
+    public function column_class($column, $classname) {
         if (isset($this->column_class[$column])) {
-            $this->column_class[$column] = ' '.$classname; // This space needed so that classnames don't run together in the HTML
+            $this->column_class[$column] = ' ' . $classname; // This space needed so that classnames don't run together in the HTML.
         }
     }
 
@@ -420,7 +421,7 @@ class flexible_table {
      * @param mixed $value
      * @return void
      */
-    function column_style($column, $property, $value) {
+    public function column_style($column, $property, $value) {
         if (isset($this->column_style[$column])) {
             $this->column_style[$column][$property] = $value;
         }
@@ -453,7 +454,7 @@ class flexible_table {
      * @param string $value
      * @return void
      */
-    function column_style_all($property, $value) {
+    public function column_style_all($property, $value) {
         foreach (array_keys($this->columns) as $column) {
             $this->column_style[$column][$property] = $value;
         }
@@ -463,25 +464,27 @@ class flexible_table {
      * Sets $this->baseurl.
      * @param moodle_url|string $url the url with params needed to call up this page
      */
-    function define_baseurl($url) {
+    public function define_baseurl($url) {
         $this->baseurl = new moodle_url($url);
     }
 
     /**
+     * Define the columns for the table.
+     *
      * @param array $columns an array of identifying names for columns. If
      * columns are sorted then column names must correspond to a field in sql.
      */
-    function define_columns($columns) {
-        $this->columns = array();
-        $this->column_style = array();
-        $this->column_class = array();
+    public function define_columns($columns) {
+        $this->columns = [];
+        $this->column_style = [];
+        $this->column_class = [];
         $this->columnsticky = [];
         $this->columnsattributes = [];
         $colnum = 0;
 
         foreach ($columns as $column) {
             $this->columns[$column]         = $colnum++;
-            $this->column_style[$column]    = array();
+            $this->column_style[$column]    = [];
             $this->column_class[$column]    = '';
             $this->columnsticky[$column]    = '';
             $this->columnsattributes[$column] = [];
@@ -490,10 +493,12 @@ class flexible_table {
     }
 
     /**
+     * Define the headers for the table, replacing any existing header configuration.
+     *
      * @param array $headers numerical keyed array of displayed string titles
      * for each column.
      */
-    function define_headers($headers) {
+    public function define_headers($headers) {
         $this->headers = $headers;
     }
 
@@ -537,14 +542,13 @@ class flexible_table {
         }
 
         return $this->resetting;
-}
+    }
 
     /**
      * Must be called after table is defined. Use methods above first. Cannot
      * use functions below till after calling this method.
      */
-    function setup() {
-
+    public function setup() {
         if (empty($this->columns) || empty($this->uniqueid)) {
             return false;
         }
@@ -563,7 +567,7 @@ class flexible_table {
 
         $this->setup = true;
 
-        // Always introduce the "flexible" class for the table if not specified
+        // Always introduce the "flexible" class for the table if not specified.
         if (empty($this->attributes)) {
             $this->attributes['class'] = 'flexible table table-striped table-hover';
         } else if (!isset($this->attributes['class'])) {
@@ -590,7 +594,7 @@ class flexible_table {
             return '';
         }
         if (empty($prefs['textsort'])) {
-            $prefs['textsort'] = array();
+            $prefs['textsort'] = [];
         }
 
         return self::construct_order_by($prefs['sortby'], $prefs['textsort']);
@@ -598,12 +602,13 @@ class flexible_table {
 
     /**
      * Prepare an an order by clause from the list of columns to be sorted.
+     *
      * @param array $cols column name => SORT_ASC or SORT_DESC
      * @return string SQL fragment that can be used in an ORDER BY clause.
      */
-    public static function construct_order_by($cols, $textsortcols=array()) {
+    public static function construct_order_by($cols, $textsortcols = []) {
         global $DB;
-        $bits = array();
+        $bits = [];
 
         foreach ($cols as $column => $order) {
             if (in_array($column, $textsortcols)) {
@@ -620,6 +625,8 @@ class flexible_table {
     }
 
     /**
+     * Get the SQL Sort clause for the table.
+     *
      * @return string SQL fragment that can be used in an ORDER BY clause.
      */
     public function get_sql_sort() {
@@ -638,7 +645,7 @@ class flexible_table {
     }
 
     /**
-     * Get the columns to sort by, in the form required by {@link construct_order_by()}.
+     * Get the columns to sort by, in the form required by {@see construct_order_by()}.
      * @return array column name => SORT_... constant.
      */
     public function get_sort_columns() {
@@ -647,7 +654,7 @@ class flexible_table {
         }
 
         if (empty($this->prefs['sortby'])) {
-            return array();
+            return [];
         }
         foreach ($this->prefs['sortby'] as $column => $notused) {
             if (isset($this->columns[$column])) {
@@ -664,9 +671,11 @@ class flexible_table {
     }
 
     /**
+     * Get the starting row number for this page.
+     *
      * @return int the offset for LIMIT clause of SQL
      */
-    function get_page_start() {
+    public function get_page_start() {
         if (!$this->use_pages) {
             return '';
         }
@@ -676,7 +685,7 @@ class flexible_table {
     /**
      * @return int the pagesize for LIMIT clause of SQL
      */
-    function get_page_size() {
+    public function get_page_size() {
         if (!$this->use_pages) {
             return '';
         }
@@ -686,27 +695,27 @@ class flexible_table {
     /**
      * @return array sql to add to where statement.
      */
-    function get_sql_where() {
+    public function get_sql_where() {
         global $DB;
 
-        $conditions = array();
-        $params = array();
+        $conditions = [];
+        $params = [];
 
         if ($this->contains_fullname_columns()) {
             static $i = 0;
             $i++;
 
             if (!empty($this->prefs['i_first'])) {
-                $conditions[] = $DB->sql_like('firstname', ':ifirstc'.$i, false, false);
-                $params['ifirstc'.$i] = $this->prefs['i_first'].'%';
+                $conditions[] = $DB->sql_like('firstname', ':ifirstc' . $i, false, false);
+                $params['ifirstc' . $i] = $this->prefs['i_first'] . '%';
             }
             if (!empty($this->prefs['i_last'])) {
-                $conditions[] = $DB->sql_like('lastname', ':ilastc'.$i, false, false);
-                $params['ilastc'.$i] = $this->prefs['i_last'].'%';
+                $conditions[] = $DB->sql_like('lastname', ':ilastc' . $i, false, false);
+                $params['ilastc' . $i] = $this->prefs['i_last'] . '%';
             }
         }
 
-        return array(implode(" AND ", $conditions), $params);
+        return [implode(" AND ", $conditions), $params];
     }
 
     /**
@@ -723,7 +732,7 @@ class flexible_table {
      *                                      as defined in call to define_columns.
      * @param string $classname CSS class name to add to this row's tr tag.
      */
-    function add_data_keyed($rowwithkeys, $classname = '') {
+    public function add_data_keyed($rowwithkeys, $classname = '') {
         $this->add_data($this->get_row_from_keyed($rowwithkeys), $classname);
     }
 
@@ -751,11 +760,11 @@ class flexible_table {
     /**
      * Add a seperator line to table.
      */
-    function add_separator() {
+    public function add_separator() {
         if (!$this->setup) {
             return false;
         }
-        $this->add_data(NULL);
+        $this->add_data(null);
     }
 
     /**
@@ -769,14 +778,14 @@ class flexible_table {
      * @param string $classname CSS class name to add to this row's tr tag.
      * @return bool success.
      */
-    function add_data($row, $classname = '') {
+    public function add_data($row, $classname = '') {
         if (!$this->setup) {
             return false;
         }
         if (!$this->started_output) {
             $this->start_output();
         }
-        if ($this->exportclass!==null) {
+        if ($this->exportclass !== null) {
             if ($row === null) {
                 $this->exportclass->add_seperator();
             } else {
@@ -793,8 +802,8 @@ class flexible_table {
      * data to the table with add_data or add_data_keyed.
      *
      */
-    function finish_output($closeexportclassdoc = true) {
-        if ($this->exportclass!==null) {
+    public function finish_output($closeexportclassdoc = true) {
+        if ($this->exportclass !== null) {
             $this->exportclass->finish_table();
             if ($closeexportclassdoc) {
                 $this->exportclass->finish_document();
@@ -809,7 +818,7 @@ class flexible_table {
      * for example. Called only when there is data to display and not
      * downloading.
      */
-    function wrap_html_start() {
+    public function wrap_html_start() {
     }
 
     /**
@@ -817,7 +826,7 @@ class flexible_table {
      * for example. Called only when there is data to display and not
      * downloading.
      */
-    function wrap_html_finish() {
+    public function wrap_html_finish() {
     }
 
     /**
@@ -830,18 +839,18 @@ class flexible_table {
      * @param array|object $row row of data from db used to make one row of the table.
      * @return array one row for the table, added using add_data_keyed method.
      */
-    function format_row($row) {
+    public function format_row($row) {
         if (is_array($row)) {
             $row = (object)$row;
         }
-        $formattedrow = array();
+        $formattedrow = [];
         foreach (array_keys($this->columns) as $column) {
-            $colmethodname = 'col_'.$column;
+            $colmethodname = 'col_' . $column;
             if (method_exists($this, $colmethodname)) {
                 $formattedcolumn = $this->$colmethodname($row);
             } else {
                 $formattedcolumn = $this->other_cols($column, $row);
-                if ($formattedcolumn===NULL) {
+                if ($formattedcolumn === null) {
                     $formattedcolumn = $row->$column;
                 }
             }
@@ -862,7 +871,7 @@ class flexible_table {
      *                    current language.
      * @return string contents of cell in column 'fullname', for this row.
      */
-    function col_fullname($row) {
+    public function col_fullname($row) {
         global $COURSE;
 
         $name = fullname($row, has_capability('moodle/site:viewfullnames', $this->get_context()));
@@ -872,10 +881,12 @@ class flexible_table {
 
         $userid = $row->{$this->useridfield};
         if ($COURSE->id == SITEID) {
-            $profileurl = new moodle_url('/user/profile.php', array('id' => $userid));
+            $profileurl = new moodle_url('/user/profile.php', ['id' => $userid]);
         } else {
-            $profileurl = new moodle_url('/user/view.php',
-                    array('id' => $userid, 'course' => $COURSE->id));
+            $profileurl = new moodle_url(
+                '/user/view.php',
+                ['id' => $userid, 'course' => $COURSE->id]
+            );
         }
         return html_writer::link($profileurl, $name);
     }
@@ -884,14 +895,16 @@ class flexible_table {
      * You can override this method in a child class. See the description of
      * build_table which calls this method.
      */
-    function other_cols($column, $row) {
-        if (isset($row->$column) && ($column === 'email' || $column === 'idnumber') &&
-                (!$this->is_downloading() || $this->export_class_instance()->supports_html())) {
+    public function other_cols($column, $row) {
+        if (
+            isset($row->$column) && ($column === 'email' || $column === 'idnumber') &&
+                (!$this->is_downloading() || $this->export_class_instance()->supports_html())
+        ) {
             // Columns email and idnumber may potentially contain malicious characters, escape them by default.
             // This function will not be executed if the child class implements col_email() or col_idnumber().
             return s($row->$column);
         }
-        return NULL;
+        return null;
     }
 
     /**
@@ -901,12 +914,12 @@ class flexible_table {
      * are the same as format_text function in weblib.php but some default
      * options are changed.
      */
-    function format_text($text, $format=FORMAT_MOODLE, $options=NULL, $courseid=NULL) {
+    public function format_text($text, $format = FORMAT_MOODLE, $options = null, $courseid = null) {
         if (!$this->is_downloading()) {
             if (is_null($options)) {
-                $options = new stdClass;
+                $options = new stdClass();
             }
-            //some sensible defaults
+            // Some sensible defaults.
             if (!isset($options->para)) {
                 $options->para = false;
             }
@@ -926,7 +939,7 @@ class flexible_table {
      * This method is deprecated although the old api is still supported.
      * @deprecated 1.9.2 - Jun 2, 2008
      */
-    function print_html() {
+    public function print_html() {
         if (!$this->setup) {
             return false;
         }
@@ -937,9 +950,9 @@ class flexible_table {
      * This function is not part of the public api.
      * @return string initial of first name we are currently filtering by
      */
-    function get_initial_first() {
+    public function get_initial_first() {
         if (!$this->use_initials) {
-            return NULL;
+            return null;
         }
 
         return $this->prefs['i_first'];
@@ -949,16 +962,16 @@ class flexible_table {
      * This function is not part of the public api.
      * @return string initial of last name we are currently filtering by
      */
-    function get_initial_last() {
+    public function get_initial_last() {
         if (!$this->use_initials) {
-            return NULL;
+            return null;
         }
 
         return $this->prefs['i_last'];
     }
 
     /**
-     * Helper function, used by {@link print_initials_bar()} to output one initial bar.
+     * Helper function, used by {@see print_initials_bar()} to output one initial bar.
      * @param array $alpha of letters in the alphabet.
      * @param string $current the currently selected letter.
      * @param string $class class name to add to this initial bar.
@@ -972,10 +985,10 @@ class flexible_table {
         debugging('Method print_one_initials_bar() is no longer used and has been deprecated, ' .
             'to print initials bar call print_initials_bar()', DEBUG_DEVELOPER);
 
-        echo html_writer::start_tag('div', array('class' => 'initialbar ' . $class)) .
+        echo html_writer::start_tag('div', ['class' => 'initialbar ' . $class]) .
             $title . ' : ';
         if ($current) {
-            echo html_writer::link($this->baseurl->out(false, array($urlvar => '')), get_string('all'));
+            echo html_writer::link($this->baseurl->out(false, [$urlvar => '']), get_string('all'));
         } else {
             echo html_writer::tag('strong', get_string('all'));
         }
@@ -984,7 +997,7 @@ class flexible_table {
             if ($letter === $current) {
                 echo html_writer::tag('strong', $letter);
             } else {
-                echo html_writer::link($this->baseurl->out(false, array($urlvar => $letter)), $letter);
+                echo html_writer::link($this->baseurl->out(false, [$urlvar => $letter]), $letter);
             }
         }
 
@@ -994,7 +1007,7 @@ class flexible_table {
     /**
      * This function is not part of the public api.
      */
-    function print_initials_bar() {
+    public function print_initials_bar() {
         global $OUTPUT;
 
         $ifirst = $this->get_initial_first();
@@ -1012,13 +1025,12 @@ class flexible_table {
             echo $OUTPUT->initials_bar($ifirst, 'firstinitial', get_string('firstname'), $prefixfirst, $this->baseurl);
             echo $OUTPUT->initials_bar($ilast, 'lastinitial', get_string('lastname'), $prefixlast, $this->baseurl);
         }
-
     }
 
     /**
      * This function is not part of the public api.
      */
-    function print_nothing_to_display() {
+    public function print_nothing_to_display() {
         global $OUTPUT;
 
         // Render the dynamic table header.
@@ -1038,16 +1050,16 @@ class flexible_table {
     /**
      * This function is not part of the public api.
      */
-    function get_row_from_keyed($rowwithkeys) {
+    public function get_row_from_keyed($rowwithkeys) {
         if (is_object($rowwithkeys)) {
             $rowwithkeys = (array)$rowwithkeys;
         }
-        $row = array();
+        $row = [];
         foreach (array_keys($this->columns) as $column) {
             if (isset($rowwithkeys[$column])) {
-                $row [] = $rowwithkeys[$column];
+                $row[] = $rowwithkeys[$column];
             } else {
-                $row[] ='';
+                $row[] = '';
             }
         }
         return $row;
@@ -1062,8 +1074,12 @@ class flexible_table {
         global $OUTPUT;
 
         if ($this->is_downloadable() && !$this->is_downloading()) {
-            return $OUTPUT->download_dataformat_selector(get_string('downloadas', 'table'),
-                    $this->baseurl->out_omit_querystring(), 'download', $this->baseurl->params());
+            return $OUTPUT->download_dataformat_selector(
+                get_string('downloadas', 'table'),
+                $this->baseurl->out_omit_querystring(),
+                'download',
+                $this->baseurl->params()
+            );
         } else {
             return '';
         }
@@ -1075,9 +1091,9 @@ class flexible_table {
      * needed when you start adding data to the table.
      *
      */
-    function start_output() {
+    public function start_output() {
         $this->started_output = true;
-        if ($this->exportclass!==null) {
+        if ($this->exportclass !== null) {
             $this->exportclass->start_table($this->sheettitle);
             $this->exportclass->output_headers($this->headers);
         } else {
@@ -1090,7 +1106,7 @@ class flexible_table {
     /**
      * This function is not part of the public api.
      */
-    function print_row($row, $classname = '') {
+    public function print_row($row, $classname = '') {
         echo $this->get_row_html($row, $classname);
     }
 
@@ -1103,8 +1119,8 @@ class flexible_table {
      * @return string $html html code for the row passed.
      */
     public function get_row_html($row, $classname = '') {
-        static $suppress_lastrow = NULL;
-        $rowclasses = array();
+        static $suppresslastrow = null;
+        $rowclasses = [];
 
         if ($classname) {
             $rowclasses[] = $classname;
@@ -1113,23 +1129,25 @@ class flexible_table {
         $rowid = $this->uniqueid . '_r' . $this->currentrow;
         $html = '';
 
-        $html .= html_writer::start_tag('tr', array('class' => implode(' ', $rowclasses), 'id' => $rowid));
+        $html .= html_writer::start_tag('tr', ['class' => implode(' ', $rowclasses), 'id' => $rowid]);
 
-        // If we have a separator, print it
-        if ($row === NULL) {
+        // If we have a separator, print it.
+        if ($row === null) {
             $colcount = count($this->columns);
-            $html .= html_writer::tag('td', html_writer::tag('div', '',
-                    array('class' => 'tabledivider')), array('colspan' => $colcount));
-
+            $html .= html_writer::tag('td', html_writer::tag(
+                'div',
+                '',
+                ['class' => 'tabledivider']
+            ), ['colspan' => $colcount]);
         } else {
-            $html .= $this->get_row_cells_html($rowid, $row, $suppress_lastrow);
+            $html .= $this->get_row_cells_html($rowid, $row, $suppresslastrow);
         }
 
         $html .= html_writer::end_tag('tr');
 
-        $suppress_enabled = array_sum($this->column_suppress);
-        if ($suppress_enabled) {
-            $suppress_lastrow = $row;
+        $suppressenabled = array_sum($this->column_suppress);
+        if ($suppressenabled) {
+            $suppresslastrow = $row;
         }
         $this->currentrow++;
         return $html;
@@ -1187,13 +1205,12 @@ class flexible_table {
     /**
      * This function is not part of the public api.
      */
-    function finish_html() {
+    public function finish_html() {
         global $OUTPUT, $PAGE;
 
         if (!$this->started_output) {
-            //no data has been added to the table.
+            // No data has been added to the table.
             $this->print_nothing_to_display();
-
         } else {
             // Print empty rows to fill the table to the current pagesize.
             // This is done so the header aria-controls attributes do not point to
@@ -1208,12 +1225,12 @@ class flexible_table {
             echo html_writer::end_tag('div');
             $this->wrap_html_finish();
 
-            // Paging bar
-            if(in_array(TABLE_P_BOTTOM, $this->showdownloadbuttonsat)) {
+            // Paging bar.
+            if (in_array(TABLE_P_BOTTOM, $this->showdownloadbuttonsat)) {
                 echo $this->download_buttons();
             }
 
-            if($this->use_pages) {
+            if ($this->use_pages) {
                 $pagingbar = new paging_bar($this->totalrows, $this->currpage, $this->pagesize, $this->baseurl);
                 $pagingbar->pagevar = $this->request[TABLE_VAR_PAGE];
                 echo $OUTPUT->render($pagingbar);
@@ -1226,7 +1243,7 @@ class flexible_table {
 
     /**
      * Generate the HTML for the collapse/uncollapse icon. This is a helper method
-     * used by {@link print_headers()}.
+     * used by {@see print_headers()}.
      * @param string $column the column name, index into various names.
      * @param int $index numerical index of the column.
      * @return string HTML fragment.
@@ -1252,10 +1269,12 @@ class flexible_table {
                 'data-column' => $column,
                 'role' => 'button',
             ];
-            return html_writer::link($this->baseurl->out(false, array($this->request[TABLE_VAR_SHOW] => $column)),
-                    $OUTPUT->pix_icon('t/switch_plus', null), $linkattributes);
-
-        } else if ($this->headers[$index] !== NULL) {
+            return html_writer::link(
+                $this->baseurl->out(false, [$this->request[TABLE_VAR_SHOW] => $column]),
+                $OUTPUT->pix_icon('t/switch_plus', null),
+                $linkattributes
+            );
+        } else if ($this->headers[$index] !== null) {
             $linkattributes = [
                 'title' => get_string('hide') . ' ' . strip_tags($this->headers[$index]),
                 'aria-expanded' => 'true',
@@ -1264,15 +1283,18 @@ class flexible_table {
                 'data-column' => $column,
                 'role' => 'button',
             ];
-            return html_writer::link($this->baseurl->out(false, array($this->request[TABLE_VAR_HIDE] => $column)),
-                    $OUTPUT->pix_icon('t/switch_minus', null), $linkattributes);
+            return html_writer::link(
+                $this->baseurl->out(false, [$this->request[TABLE_VAR_HIDE] => $column]),
+                $OUTPUT->pix_icon('t/switch_minus', null),
+                $linkattributes
+            );
         }
     }
 
     /**
      * This function is not part of the public api.
      */
-    function print_headers() {
+    public function print_headers() {
         global $CFG, $OUTPUT;
 
         // Set the primary sort column/order where possible, so that sort links/icons are correct.
@@ -1284,19 +1306,16 @@ class flexible_table {
         echo html_writer::start_tag('thead');
         echo html_writer::start_tag('tr');
         foreach ($this->columns as $column => $index) {
-
-            $icon_hide = '';
+            $iconhide = '';
             if ($this->is_collapsible) {
-                $icon_hide = $this->show_hide_link($column, $index);
+                $iconhide = $this->show_hide_link($column, $index);
             }
             switch ($column) {
-
                 case 'userpic':
-                    // do nothing, do not display sortable links
+                    // Do nothing, do not display sortable links.
                     break;
 
                 default:
-
                     if (array_search($column, $this->userfullnamecolumns) !== false) {
                         // Check the full name display for sortable fields.
                         if (has_capability('moodle/site:viewfullnames', $this->get_context())) {
@@ -1316,8 +1335,12 @@ class flexible_table {
                                 // Done this way for the possibility of more than two sortable full name display fields.
                                 $this->headers[$index] = '';
                                 foreach ($requirednames as $name) {
-                                    $sortname = $this->sort_link(get_string($name),
-                                        $name, $primarysortcolumn === $name, $primarysortorder);
+                                    $sortname = $this->sort_link(
+                                        get_string($name),
+                                        $name,
+                                        $primarysortcolumn === $name,
+                                        $primarysortorder
+                                    );
                                     $this->headers[$index] .= $sortname . ' / ';
                                 }
                                 $helpicon = '';
@@ -1332,19 +1355,23 @@ class flexible_table {
                         if (isset($this->helpforheaders[$index])) {
                             $helpicon = $OUTPUT->render($this->helpforheaders[$index]);
                         }
-                        $this->headers[$index] = $this->sort_link($this->headers[$index],
-                                $column, $primarysortcolumn == $column, $primarysortorder) . $helpicon;
+                        $this->headers[$index] = $this->sort_link(
+                            $this->headers[$index],
+                            $column,
+                            $primarysortcolumn == $column,
+                            $primarysortorder
+                        ) . $helpicon;
                     }
             }
 
-            $attributes = array(
+            $attributes = [
                 'class' => 'header c' . $index . $this->column_class[$column] . $this->columnsticky[$column],
                 'scope' => 'col',
-            );
-            if ($this->headers[$index] === NULL) {
+            ];
+            if ($this->headers[$index] === null) {
                 $content = '&nbsp;';
             } else if (!empty($this->prefs['collapse'][$column])) {
-                $content = $icon_hide;
+                $content = $iconhide;
             } else {
                 if (is_array($this->column_style[$column])) {
                     $attributes['style'] = $this->make_styles_string($this->column_style[$column]);
@@ -1353,8 +1380,11 @@ class flexible_table {
                 if (isset($this->helpforheaders[$index]) && !$this->is_sortable($column)) {
                     $helpicon  = $OUTPUT->render($this->helpforheaders[$index]);
                 }
-                $content = $this->headers[$index] . $helpicon . html_writer::tag('div',
-                        $icon_hide, array('class' => 'commands'));
+                $content = $this->headers[$index] . $helpicon . html_writer::tag(
+                    'div',
+                    $iconhide,
+                    ['class' => 'commands']
+                );
             }
             echo html_writer::tag('th', $content, $attributes);
         }
@@ -1383,7 +1413,7 @@ class flexible_table {
         }
 
         $usernamefields = \core_user\fields::get_name_fields();
-        $sortdata = array_filter($sortdata, function($sortby) use ($usernamefields) {
+        $sortdata = array_filter($sortdata, function ($sortby) use ($usernamefields) {
             $isvalidsort = $sortby && $this->is_sortable($sortby);
             $isvalidsort = $isvalidsort && empty($this->prefs['collapse'][$sortby]);
             $isrealcolumn = isset($this->columns[$sortby]);
@@ -1427,7 +1457,6 @@ class flexible_table {
         if (!is_null($ilast) && ($ilast === '' || strpos(get_string('alphabet', 'langconfig'), $ilast) !== false)) {
             $this->prefs['i_last'] = $ilast;
         }
-
     }
 
     /**
@@ -1436,7 +1465,7 @@ class flexible_table {
     protected function set_hide_show_preferences(): void {
 
         if ($this->hiddencolumns !== null) {
-            $this->prefs['collapse'] = array_fill_keys(array_filter($this->hiddencolumns, function($column) {
+            $this->prefs['collapse'] = array_fill_keys(array_filter($this->hiddencolumns, function ($column) {
                 return array_key_exists($column, $this->columns);
             }), true);
         } else {
@@ -1504,11 +1533,15 @@ class flexible_table {
             $this->ilast = null;
         }
 
-        if (($showcol = optional_param($this->request[TABLE_VAR_SHOW], '', PARAM_ALPHANUMEXT)) &&
-            isset($this->columns[$showcol])) {
+        if (
+            ($showcol = optional_param($this->request[TABLE_VAR_SHOW], '', PARAM_ALPHANUMEXT)) &&
+            isset($this->columns[$showcol])
+        ) {
             $this->prefs['collapse'][$showcol] = false;
-        } else if (($hidecol = optional_param($this->request[TABLE_VAR_HIDE], '', PARAM_ALPHANUMEXT)) &&
-            isset($this->columns[$hidecol])) {
+        } else if (
+            ($hidecol = optional_param($this->request[TABLE_VAR_HIDE], '', PARAM_ALPHANUMEXT)) &&
+            isset($this->columns[$hidecol])
+        ) {
             $this->prefs['collapse'][$hidecol] = true;
             if (array_key_exists($hidecol, $this->prefs['sortby'])) {
                 unset($this->prefs['sortby'][$hidecol]);
@@ -1620,7 +1653,7 @@ class flexible_table {
     }
 
     /**
-     * Generate the HTML for the sort icon. This is a helper method used by {@link sort_link()}.
+     * Generate the HTML for the sort icon. This is a helper method used by {@see sort_link()}.
      * @param bool $isprimary whether an icon is needed (it is only needed for the primary sort column.)
      * @param int $order SORT_ASC or SORT_DESC
      * @return string HTML fragment.
@@ -1641,7 +1674,7 @@ class flexible_table {
 
     /**
      * Generate the correct tool tip for changing the sort order. This is a
-     * helper method used by {@link sort_link()}.
+     * helper method used by {@see sort_link()}.
      * @param bool $isprimary whether the is column is the current primary sort column.
      * @param int $order SORT_ASC or SORT_DESC
      * @return string the correct title.
@@ -1655,7 +1688,7 @@ class flexible_table {
     }
 
     /**
-     * Generate the HTML for the sort link. This is a helper method used by {@link print_headers()}.
+     * Generate the HTML for the sort link. This is a helper method used by {@see print_headers()}.
      * @param string $text the text for the link.
      * @param string $column the column name, may be a fake column like 'firstname' or a real one.
      * @param bool $isprimary whether the is column is the current primary sort column.
@@ -1675,15 +1708,17 @@ class flexible_table {
             $this->request[TABLE_VAR_DIR] => $sortorder,
         ];
 
-        return html_writer::link($this->baseurl->out(false, $params),
-                $text . get_accesshide(get_string('sortby') . ' ' .
+        return html_writer::link(
+            $this->baseurl->out(false, $params),
+            $text . get_accesshide(get_string('sortby') . ' ' .
                 $text . ' ' . $this->sort_order_name($isprimary, $order)),
-                [
+            [
                     'data-sortable' => $this->is_sortable($column),
                     'data-sortby' => $column,
                     'data-sortorder' => $sortorder,
                     'role' => 'button',
-                ]) . ' ' . $this->sort_icon($isprimary, $order);
+            ]
+        ) . ' ' . $this->sort_icon($isprimary, $order);
     }
 
     /**
@@ -1745,12 +1780,13 @@ class flexible_table {
      */
     protected function get_dynamic_table_html_start(): string {
         if (is_a($this, dynamic::class)) {
-            $sortdata = array_map(function($sortby, $sortorder) {
+            $sortdata = array_map(function ($sortby, $sortorder) {
                 return [
                     'sortby' => $sortby,
                     'sortorder' => $sortorder,
                 ];
-            }, array_keys($this->prefs['sortby']), array_values($this->prefs['sortby']));;
+            }, array_keys($this->prefs['sortby']), array_values($this->prefs['sortby']));
+            ;
 
             return html_writer::start_tag('div', [
                 'class' => 'table-dynamic position-relative',
@@ -1818,7 +1854,7 @@ class flexible_table {
     /**
      * This function is not part of the public api.
      */
-    function start_html() {
+    public function start_html() {
         global $OUTPUT;
 
         // Render the dynamic table header.
@@ -1830,7 +1866,7 @@ class flexible_table {
         // Do we need to print initial bars?
         $this->print_initials_bar();
 
-        // Paging bar
+        // Paging bar.
         if ($this->use_pages) {
             $pagingbar = new paging_bar($this->totalrows, $this->currpage, $this->pagesize, $this->baseurl);
             $pagingbar->pagevar = $this->request[TABLE_VAR_PAGE];
@@ -1842,9 +1878,9 @@ class flexible_table {
         }
 
         $this->wrap_html_start();
-        // Start of main data table
+        // Start of main data table.
 
-        echo html_writer::start_tag('div', array('class' => 'no-overflow'));
+        echo html_writer::start_tag('div', ['class' => 'no-overflow']);
         echo html_writer::start_tag('table', $this->attributes) . $this->render_caption();
     }
 
@@ -1881,13 +1917,13 @@ class flexible_table {
      * @param array $styles CSS-property => value
      * @return string values suitably to go in a style="" attribute in HTML.
      */
-    function make_styles_string($styles) {
+    public function make_styles_string($styles) {
         if (empty($styles)) {
             return null;
         }
 
         $string = '';
-        foreach($styles as $property => $value) {
+        foreach ($styles as $property => $value) {
             $string .= $property . ':' . $value . ';';
         }
         return $string;
@@ -1904,7 +1940,7 @@ class flexible_table {
             return '';
         }
 
-        $url = $this->baseurl->out(false, array($this->request[TABLE_VAR_RESET] => 1));
+        $url = $this->baseurl->out(false, [$this->request[TABLE_VAR_RESET] => 1]);
 
         $html  = html_writer::start_div('resettable mdl-right');
         $html .= html_writer::link($url, get_string('resettable'), ['role' => 'button']);
@@ -1923,20 +1959,18 @@ class flexible_table {
     protected function can_be_reset() {
         // Loop through preferences and make sure they are empty or set to the default value.
         foreach ($this->prefs as $prefname => $prefval) {
-            if ($prefname === 'sortby' and !empty($this->sort_default_column)) {
+            if ($prefname === 'sortby' && !empty($this->sort_default_column)) {
                 // Check if the actual sorting differs from the default one.
-                if (empty($prefval) or $prefval !== array($this->sort_default_column => $this->sort_default_order)) {
+                if (empty($prefval) || ($prefval !== [$this->sort_default_column => $this->sort_default_order])) {
                     return true;
                 }
-
-            } else if ($prefname === 'collapse' and !empty($prefval)) {
+            } else if ($prefname === 'collapse' && !empty($prefval)) {
                 // Check if there are some collapsed columns (all are expanded by default).
                 foreach ($prefval as $columnname => $iscollapsed) {
                     if ($iscollapsed) {
                         return true;
                     }
                 }
-
             } else if (!empty($prefval)) {
                 // For all other cases, we just check if some preference is set.
                 return true;
diff --git a/lib/table/classes/output/html_table.php b/lib/table/classes/output/html_table.php
index c04ef01bc7e..8ec95880ca0 100644
--- a/lib/table/classes/output/html_table.php
+++ b/lib/table/classes/output/html_table.php
@@ -17,7 +17,7 @@
 namespace core_table\output;
 
 /**
- * Holds all the information required to render a <table> by {@link core_renderer::table()}
+ * Holds all the information required to render a <table> by {@see core_renderer::table()}
  *
  * Example of usage:
  * $t = new html_table();
@@ -27,11 +27,10 @@ namespace core_table\output;
  * @copyright 2009 David Mudrak <david.mudrak@gmail.com>
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since Moodle 2.0
- * @package core
+ * @package core_table
  * @category output
  */
 class html_table {
-
     /**
      * @var string Value to use for the id attribute of the table
      */
@@ -40,7 +39,7 @@ class html_table {
     /**
      * @var array Attributes of HTML attributes for the <table> element
      */
-    public $attributes = array();
+    public $attributes = [];
 
     /**
      * @var array An array of headings. The n-th array item is used as a heading of the n-th column.
@@ -54,8 +53,8 @@ class html_table {
 
     /**
      * @var array An array that can be used to make a heading span multiple columns.
-     * In this example, {@link html_table:$data} is supposed to have three columns. For the first two columns,
-     * the same heading is used. Therefore, {@link html_table::$head} should consist of two items.
+     * In this example, {@see html_table:$data} is supposed to have three columns. For the first two columns,
+     * the same heading is used. Therefore, {@see html_table::$head} should consist of two items.
      *
      * Example of usage:
      * $t->headspan = array(2,1);
@@ -122,20 +121,20 @@ class html_table {
     public $data = [];
 
     /**
-     * @deprecated since Moodle 2.0. Styling should be in the CSS.
      * @var string Width of the table, percentage of the page preferred.
+     * @deprecated since Moodle 2.0. Styling should be in the CSS.
      */
     public $width = null;
 
     /**
-     * @deprecated since Moodle 2.0. Styling should be in the CSS.
      * @var string Alignment for the whole table. Can be 'right', 'left' or 'center' (default).
+     * @deprecated since Moodle 2.0. Styling should be in the CSS.
      */
     public $tablealign = null;
 
     /**
-     * @deprecated since Moodle 2.0. Styling should be in the CSS.
      * @var int Padding on each cell, in pixels
+     * @deprecated since Moodle 2.0. Styling should be in the CSS.
      */
     public $cellpadding = null;
 
diff --git a/lib/table/classes/output/html_table_cell.php b/lib/table/classes/output/html_table_cell.php
index 038fb27ad50..7f44cd96a52 100644
--- a/lib/table/classes/output/html_table_cell.php
+++ b/lib/table/classes/output/html_table_cell.php
@@ -22,7 +22,7 @@ namespace core_table\output;
  * @copyright 2009 Nicolas Connault
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since Moodle 2.0
- * @package core
+ * @package core_table
  * @category output
  */
 class html_table_cell {
@@ -69,7 +69,7 @@ class html_table_cell {
     /**
      * @var array Attributes of additional HTML attributes for the <td> element
      */
-    public $attributes = array();
+    public $attributes = [];
 
     /**
      * Constructs a table cell
diff --git a/lib/table/classes/output/html_table_row.php b/lib/table/classes/output/html_table_row.php
index 6b92c0a5486..b70a7dcd400 100644
--- a/lib/table/classes/output/html_table_row.php
+++ b/lib/table/classes/output/html_table_row.php
@@ -22,7 +22,7 @@ namespace core_table\output;
  * @copyright 2009 Nicolas Connault
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @since Moodle 2.0
- * @package core
+ * @package core_table
  * @category output
  */
 class html_table_row {
@@ -34,7 +34,7 @@ class html_table_row {
     /**
      * @var array Array of html_table_cell objects
      */
-    public $cells = array();
+    public $cells = [];
 
     /**
      * @var string Value to use for the style attribute of the table row
@@ -44,13 +44,14 @@ class html_table_row {
     /**
      * @var array Attributes of additional HTML attributes for the <tr> element
      */
-    public $attributes = array();
+    public $attributes = [];
 
     /**
      * Constructor
-     * @param array $cells
+     *
+     * @param null|array $cells
      */
-    public function __construct(array $cells=null) {
+    public function __construct(?array $cells = null) {
         $this->attributes['class'] = '';
         $cells = (array)$cells;
         foreach ($cells as $cell) {
diff --git a/lib/table/classes/sql_table.php b/lib/table/classes/sql_table.php
index 00e26153535..815e81aef1f 100644
--- a/lib/table/classes/sql_table.php
+++ b/lib/table/classes/sql_table.php
@@ -29,38 +29,39 @@ require_once("{$CFG->libdir}/tablelib.php");
 /**
  * A table whose data is provided by SQL queries.
  *
- * @package   moodlecore
+ * @package   core_table
  * @copyright 1999 onwards Martin Dougiamas  {@link http://moodle.com}
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class sql_table extends flexible_table {
-    public $countsql = NULL;
-    public $countparams = NULL;
-    /**
-     * @var object sql for querying db. Has fields 'fields', 'from', 'where', 'params'.
-     */
-    public $sql = NULL;
-    /**
-     * @var array|\Traversable Data fetched from the db.
-     */
-    public $rawdata = NULL;
+    /** @var string The SQL query to count records */
+    public $countsql = null;
 
-    /**
-     * @var bool Overriding default for this.
-     */
-    public $is_sortable    = true;
-    /**
-     * @var bool Overriding default for this.
-     */
-    public $is_collapsible = true;
+    /** @var array The parameters for the Count SQL */
+    public $countparams = null;
+
+    /** @var object sql for querying db. Has fields 'fields', 'from', 'where', 'params' */
+    public $sql = null;
+
+    /** @var array|\Traversable Data fetched from the db */
+    public $rawdata = null;
+
+    /** @var bool Overriding default for this */
+
+    public $is_sortable = true; // phpcs:ignore moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
+
+    /** @var bool Overriding default for this */
+    public $is_collapsible = true; // phpcs:ignore moodle.NamingConventions.ValidVariableName.MemberNameUnderscore
 
     /**
+     * Create a new instance of the sql_table.
+     *
      * @param string $uniqueid a string identifying this table.Used as a key in
      *                          session  vars.
      */
-    function __construct($uniqueid) {
+    public function __construct($uniqueid) {
         parent::__construct($uniqueid);
-        // some sensible defaults
+        // Set some sensible defaults.
         $this->set_attribute('class', 'generaltable generalbox');
     }
 
@@ -89,8 +90,10 @@ class sql_table extends flexible_table {
      * Closes recordset (for use after building the table).
      */
     public function close_recordset() {
-        if ($this->rawdata && ($this->rawdata instanceof \core\dml\recordset_walk ||
-                $this->rawdata instanceof moodle_recordset)) {
+        if (
+            $this->rawdata && ($this->rawdata instanceof \core\dml\recordset_walk ||
+                $this->rawdata instanceof moodle_recordset)
+        ) {
             $this->rawdata->close();
             $this->rawdata = null;
         }
@@ -98,14 +101,17 @@ class sql_table extends flexible_table {
 
     /**
      * Get any extra classes names to add to this row in the HTML.
-     * @param $row array the data for this row.
+     *
+     * @param array $row the data for this row.
      * @return string added to the class="" attribute of the tr.
      */
-    function get_row_class($row) {
+    public function get_row_class($row) {
         return '';
     }
 
     /**
+     * Set the SQL used to count records.
+     *
      * This is only needed if you want to use different sql to count rows.
      * Used for example when perhaps all db JOINS are not needed when counting
      * records. You don't need to call this function the count_sql
@@ -113,8 +119,11 @@ class sql_table extends flexible_table {
      *
      * We need to count rows returned by the db seperately to the query itself
      * as we need to know how many pages of data we have to display.
+     *
+     * @param string $sql
+     * @param null|array $params
      */
-    function set_count_sql($sql, array $params = NULL) {
+    public function set_count_sql($sql, ?array $params = null) {
         $this->countsql = $sql;
         $this->countparams = $params;
     }
@@ -124,8 +133,13 @@ class sql_table extends flexible_table {
      *      SELECT $fields FROM $from WHERE $where
      * Of course you can use sub-queries, JOINS etc. by putting them in the
      * appropriate clause of the query.
+     *
+     * @param string $fields
+     * @param string $from
+     * @param string $where
+     * @param array $params
      */
-    function set_sql($fields, $from, $where, array $params = array()) {
+    public function set_sql($fields, $from, $where, array $params = []) {
         $this->sql = new stdClass();
         $this->sql->fields = $fields;
         $this->sql->from = $from;
@@ -140,11 +154,11 @@ class sql_table extends flexible_table {
      * @param bool $useinitialsbar do you want to use the initials bar. Bar
      * will only be used if there is a fullname column defined for the table.
      */
-    function query_db($pagesize, $useinitialsbar=true) {
+    public function query_db($pagesize, $useinitialsbar = true) {
         global $DB;
         if (!$this->is_downloading()) {
-            if ($this->countsql === NULL) {
-                $this->countsql = 'SELECT COUNT(1) FROM '.$this->sql->from.' WHERE '.$this->sql->where;
+            if ($this->countsql === null) {
+                $this->countsql = 'SELECT COUNT(1) FROM ' . $this->sql->from . ' WHERE ' . $this->sql->where;
                 $this->countparams = $this->sql->params;
             }
             $grandtotal = $DB->count_records_sql($this->countsql, $this->countparams);
@@ -152,12 +166,12 @@ class sql_table extends flexible_table {
                 $this->initialbars(true);
             }
 
-            list($wsql, $wparams) = $this->get_sql_where();
+            [$wsql, $wparams] = $this->get_sql_where();
             if ($wsql) {
-                $this->countsql .= ' AND '.$wsql;
+                $this->countsql .= ' AND ' . $wsql;
                 $this->countparams = array_merge($this->countparams, $wparams);
 
-                $this->sql->where .= ' AND '.$wsql;
+                $this->sql->where .= ' AND ' . $wsql;
                 $this->sql->params = array_merge($this->sql->params, $wparams);
 
                 $total  = $DB->count_records_sql($this->countsql, $this->countparams);
@@ -168,7 +182,7 @@ class sql_table extends flexible_table {
             $this->pagesize($pagesize, $total);
         }
 
-        // Fetch the attempts
+        // Fetch the attempts.
         $sort = $this->get_sql_sort();
         if ($sort) {
             $sort = "ORDER BY $sort";
@@ -189,14 +203,21 @@ class sql_table extends flexible_table {
     /**
      * Convenience method to call a number of methods for you to display the
      * table.
+     *
+     * @param int $pagesize
+     * @param bool $useinitialsbar
+     * @param string $downloadhelpbutton
      */
-    function out($pagesize, $useinitialsbar, $downloadhelpbutton='') {
+    public function out($pagesize, $useinitialsbar, $downloadhelpbutton = '') {
         global $DB;
         if (!$this->columns) {
-            $onerow = $DB->get_record_sql("SELECT {$this->sql->fields} FROM {$this->sql->from} WHERE {$this->sql->where}",
-                $this->sql->params, IGNORE_MULTIPLE);
-            //if columns is not set then define columns as the keys of the rows returned
-            //from the db.
+            $onerow = $DB->get_record_sql(
+                "SELECT {$this->sql->fields} FROM {$this->sql->from} WHERE {$this->sql->where}",
+                $this->sql->params,
+                IGNORE_MULTIPLE
+            );
+            // If columns is not set then define columns as the keys of the rows returned
+            // from the db.
             $this->define_columns(array_keys((array)$onerow));
             $this->define_headers(array_keys((array)$onerow));
         }
diff --git a/lib/tests/html_writer_test.php b/lib/tests/output/html_writer_test.php
similarity index 56%
rename from lib/tests/html_writer_test.php
rename to lib/tests/output/html_writer_test.php
index 7823a0def9d..afb88b4915e 100644
--- a/lib/tests/html_writer_test.php
+++ b/lib/tests/output/html_writer_test.php
@@ -14,15 +14,24 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+namespace core\output;
+
+use core_table\output\html_table;
+use core_table\output\html_table_cell;
+use core_table\output\html_table_row;
+
+// phpcs:disable moodle.Commenting.DocblockDescription.Missing
+
 /**
  * Unit tests for the html_writer class.
  *
+ * @package core
  * @copyright 2010 Tim Hunt
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
- * @covers \html_writer
- * @coversDefaultClass \html_writer
+ * @covers \core\output\html_writer
+ * @coversDefaultClass \\core\output\html_writer
  */
-final class html_writer_test extends basic_testcase {
+final class html_writer_test extends \basic_testcase {
     /**
      * @covers ::start_tag
      */
@@ -34,16 +43,20 @@ final class html_writer_test extends basic_testcase {
      * @covers ::start_tag
      */
     public function test_start_tag_with_attr(): void {
-        $this->assertSame('<div class="frog">',
-            html_writer::start_tag('div', array('class' => 'frog')));
+        $this->assertSame(
+            '<div class="frog">',
+            html_writer::start_tag('div', ['class' => 'frog'])
+        );
     }
 
     /**
      * @covers ::start_tag
      */
     public function test_start_tag_with_attrs(): void {
-        $this->assertSame('<div class="frog" id="mydiv">',
-            html_writer::start_tag('div', array('class' => 'frog', 'id' => 'mydiv')));
+        $this->assertSame(
+            '<div class="frog" id="mydiv">',
+            html_writer::start_tag('div', ['class' => 'frog', 'id' => 'mydiv']),
+        );
     }
 
     /**
@@ -64,48 +77,60 @@ final class html_writer_test extends basic_testcase {
      * @covers ::empty_Tag
      */
     public function test_empty_tag_with_attrs(): void {
-        $this->assertSame('<input type="submit" value="frog" />',
-            html_writer::empty_tag('input', array('type' => 'submit', 'value' => 'frog')));
+        $this->assertSame(
+            '<input type="submit" value="frog" />',
+            html_writer::empty_tag('input', ['type' => 'submit', 'value' => 'frog']),
+        );
     }
 
     /**
      * @covers ::nonempty_tag
      */
     public function test_nonempty_tag_with_content(): void {
-        $this->assertSame('<div>Hello world!</div>',
-            html_writer::nonempty_tag('div', 'Hello world!'));
+        $this->assertSame(
+            '<div>Hello world!</div>',
+            html_writer::nonempty_tag('div', 'Hello world!'),
+        );
     }
 
     /**
      * @covers ::nonempty_tag
      */
     public function test_nonempty_tag_empty(): void {
-        $this->assertSame('',
-            html_writer::nonempty_tag('div', ''));
+        $this->assertSame(
+            '',
+            html_writer::nonempty_tag('div', ''),
+        );
     }
 
     /**
      * @covers ::nonempty_tag
      */
     public function test_nonempty_tag_null(): void {
-        $this->assertSame('',
-            html_writer::nonempty_tag('div', null));
+        $this->assertSame(
+            '',
+            html_writer::nonempty_tag('div', null),
+        );
     }
 
     /**
      * @covers ::nonempty_tag
      */
     public function test_nonempty_tag_zero(): void {
-        $this->assertSame('<div class="score">0</div>',
-            html_writer::nonempty_tag('div', 0, array('class' => 'score')));
+        $this->assertSame(
+            '<div class="score">0</div>',
+            html_writer::nonempty_tag('div', 0, ['class' => 'score'])
+        );
     }
 
     /**
      * @covers ::nonempty_tag
      */
     public function test_nonempty_tag_zero_string(): void {
-        $this->assertSame('<div class="score">0</div>',
-            html_writer::nonempty_tag('div', '0', array('class' => 'score')));
+        $this->assertSame(
+            '<div class="score">0</div>',
+            html_writer::nonempty_tag('div', '0', ['class' => 'score'])
+        );
     }
 
     /**
@@ -113,20 +138,30 @@ final class html_writer_test extends basic_testcase {
      */
     public function test_div(): void {
         // All options.
-        $this->assertSame('<div class="frog" id="kermit">ribbit</div>',
-                html_writer::div('ribbit', 'frog', array('id' => 'kermit')));
+        $this->assertSame(
+            '<div class="frog" id="kermit">ribbit</div>',
+            html_writer::div('ribbit', 'frog', ['id' => 'kermit'])
+        );
         // Combine class from attributes and $class.
-        $this->assertSame('<div class="amphibian frog">ribbit</div>',
-                html_writer::div('ribbit', 'frog', array('class' => 'amphibian')));
+        $this->assertSame(
+            '<div class="amphibian frog">ribbit</div>',
+            html_writer::div('ribbit', 'frog', ['class' => 'amphibian'])
+        );
         // Class only.
-        $this->assertSame('<div class="frog">ribbit</div>',
-                html_writer::div('ribbit', 'frog'));
+        $this->assertSame(
+            '<div class="frog">ribbit</div>',
+            html_writer::div('ribbit', 'frog')
+        );
         // Attributes only.
-        $this->assertSame('<div id="kermit">ribbit</div>',
-                html_writer::div('ribbit', '', array('id' => 'kermit')));
+        $this->assertSame(
+            '<div id="kermit">ribbit</div>',
+            html_writer::div('ribbit', '', ['id' => 'kermit'])
+        );
         // No options.
-        $this->assertSame('<div>ribbit</div>',
-                html_writer::div('ribbit'));
+        $this->assertSame(
+            '<div>ribbit</div>',
+            html_writer::div('ribbit')
+        );
     }
 
     /**
@@ -134,20 +169,30 @@ final class html_writer_test extends basic_testcase {
      */
     public function test_start_div(): void {
         // All options.
-        $this->assertSame('<div class="frog" id="kermit">',
-                html_writer::start_div('frog', array('id' => 'kermit')));
+        $this->assertSame(
+            '<div class="frog" id="kermit">',
+            html_writer::start_div('frog', ['id' => 'kermit'])
+        );
         // Combine class from attributes and $class.
-        $this->assertSame('<div class="amphibian frog">',
-                html_writer::start_div('frog', array('class' => 'amphibian')));
+        $this->assertSame(
+            '<div class="amphibian frog">',
+            html_writer::start_div('frog', ['class' => 'amphibian'])
+        );
         // Class only.
-        $this->assertSame('<div class="frog">',
-                html_writer::start_div('frog'));
+        $this->assertSame(
+            '<div class="frog">',
+            html_writer::start_div('frog')
+        );
         // Attributes only.
-        $this->assertSame('<div id="kermit">',
-                html_writer::start_div('', array('id' => 'kermit')));
+        $this->assertSame(
+            '<div id="kermit">',
+            html_writer::start_div('', ['id' => 'kermit'])
+        );
         // No options.
-        $this->assertSame('<div>',
-                html_writer::start_div());
+        $this->assertSame(
+            '<div>',
+            html_writer::start_div()
+        );
     }
 
     /**
@@ -162,20 +207,30 @@ final class html_writer_test extends basic_testcase {
      */
     public function test_span(): void {
         // All options.
-        $this->assertSame('<span class="frog" id="kermit">ribbit</span>',
-                html_writer::span('ribbit', 'frog', array('id' => 'kermit')));
+        $this->assertSame(
+            '<span class="frog" id="kermit">ribbit</span>',
+            html_writer::span('ribbit', 'frog', ['id' => 'kermit'])
+        );
         // Combine class from attributes and $class.
-        $this->assertSame('<span class="amphibian frog">ribbit</span>',
-                html_writer::span('ribbit', 'frog', array('class' => 'amphibian')));
+        $this->assertSame(
+            '<span class="amphibian frog">ribbit</span>',
+            html_writer::span('ribbit', 'frog', ['class' => 'amphibian'])
+        );
         // Class only.
-        $this->assertSame('<span class="frog">ribbit</span>',
-                html_writer::span('ribbit', 'frog'));
+        $this->assertSame(
+            '<span class="frog">ribbit</span>',
+            html_writer::span('ribbit', 'frog')
+        );
         // Attributes only.
-        $this->assertSame('<span id="kermit">ribbit</span>',
-                html_writer::span('ribbit', '', array('id' => 'kermit')));
+        $this->assertSame(
+            '<span id="kermit">ribbit</span>',
+            html_writer::span('ribbit', '', ['id' => 'kermit'])
+        );
         // No options.
-        $this->assertSame('<span>ribbit</span>',
-                html_writer::span('ribbit'));
+        $this->assertSame(
+            '<span>ribbit</span>',
+            html_writer::span('ribbit')
+        );
     }
 
     /**
@@ -183,20 +238,30 @@ final class html_writer_test extends basic_testcase {
      */
     public function test_start_span(): void {
         // All options.
-        $this->assertSame('<span class="frog" id="kermit">',
-                html_writer::start_span('frog', array('id' => 'kermit')));
+        $this->assertSame(
+            '<span class="frog" id="kermit">',
+            html_writer::start_span('frog', ['id' => 'kermit'])
+        );
         // Combine class from attributes and $class.
-        $this->assertSame('<span class="amphibian frog">',
-                html_writer::start_span('frog', array('class' => 'amphibian')));
+        $this->assertSame(
+            '<span class="amphibian frog">',
+            html_writer::start_span('frog', ['class' => 'amphibian'])
+        );
         // Class only.
-        $this->assertSame('<span class="frog">',
-                html_writer::start_span('frog'));
+        $this->assertSame(
+            '<span class="frog">',
+            html_writer::start_span('frog')
+        );
         // Attributes only.
-        $this->assertSame('<span id="kermit">',
-                html_writer::start_span('', array('id' => 'kermit')));
+        $this->assertSame(
+            '<span id="kermit">',
+            html_writer::start_span('', ['id' => 'kermit'])
+        );
         // No options.
-        $this->assertSame('<span>',
-                html_writer::start_span());
+        $this->assertSame(
+            '<span>',
+            html_writer::start_span()
+        );
     }
 
     /**
@@ -208,9 +273,9 @@ final class html_writer_test extends basic_testcase {
 
     /**
      * @covers ::table
-     * @covers \html_table_row
-     * @covers \html_table_cell
-     * @covers \html_table
+     * @covers \core_table\output\html_table_row
+     * @covers \core_table\output\html_table_cell
+     * @covers \core_table\output\html_table
      */
     public function test_table(): void {
         $row = new html_table_row();
@@ -268,11 +333,11 @@ EOF;
 
         $table = new html_table();
         $table->id = "whodat";
-        $table->data = array(
-            array('fred', 'MDK'),
-            array('bob',  'Burgers'),
-            array('dave', 'Competitiveness')
-        );
+        $table->data = [
+            ['fred', 'MDK'],
+            ['bob', 'Burgers'],
+            ['dave', 'Competitiveness'],
+        ];
         $table->caption = "Who even knows?";
         $table->captionhide = true;
         $table->responsive = false;