From 7adac1fefbeda10f1d52c99adfd72adac0da52a1 Mon Sep 17 00:00:00 2001
From: Daniel Neis Araujo <danielneis@gmail.com>
Date: Tue, 16 Aug 2022 17:57:41 -0300
Subject: [PATCH] MDL-75218 theme: Add a Favicon setting

---
 admin/lib.php                 |  2 +-
 admin/settings/appearance.php |  8 ++++++++
 lang/en/admin.php             |  2 ++
 lib/outputrenderers.php       | 10 +++++++++-
 theme/upgrade.txt             |  1 +
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/admin/lib.php b/admin/lib.php
index 39550844fc2..d9a722d818a 100644
--- a/admin/lib.php
+++ b/admin/lib.php
@@ -55,7 +55,7 @@ function admin_page_type_list($pagetype, $parentcontext, $currentcontext) {
 function core_admin_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options = array()) {
     global $CFG;
 
-    if (in_array($filearea, ['logo', 'logocompact'])) {
+    if (in_array($filearea, ['logo', 'logocompact', 'favicon'])) {
         $size = array_shift($args); // The path hides the size.
         $itemid = clean_param(array_shift($args), PARAM_INT);
         $filename = clean_param(array_shift($args), PARAM_FILE);
diff --git a/admin/settings/appearance.php b/admin/settings/appearance.php
index b0547e7aaa0..e89c09a1f90 100644
--- a/admin/settings/appearance.php
+++ b/admin/settings/appearance.php
@@ -82,6 +82,14 @@ reports,core_reportbuilder|/reportbuilder/index.php',
     $setting->set_updatedcallback('theme_reset_all_caches');
     $temp->add($setting);
 
+    // Favicon file setting.
+    $title = get_string('favicon', 'admin');
+    $description = get_string('favicon_desc', 'admin');
+    $setting = new admin_setting_configstoredfile('core_admin/favicon', $title, $description, 'favicon', 0,
+        ['maxfiles' => 1, 'accepted_types' => ['image']]);
+    $setting->set_updatedcallback('theme_reset_all_caches');
+    $temp->add($setting);
+
     $ADMIN->add('appearance', $temp);
 
     // Course colours section.
diff --git a/lang/en/admin.php b/lang/en/admin.php
index 248b30d5894..dbfcf026c2a 100644
--- a/lang/en/admin.php
+++ b/lang/en/admin.php
@@ -615,6 +615,8 @@ $string['experimentalsettings'] = 'Experimental settings';
 $string['extendedusernamechars'] = 'Allow extended characters in usernames';
 $string['extramemorylimit'] = 'Extra PHP memory limit';
 $string['fatalsessionautostart'] = '<p>Serious configuration error detected, please notify server administrator.</p><p> To operate properly, Moodle requires that administrator changes PHP settings.</p><p><code>session.auto_start</code> must be set to <code>off</code>.</p><p>This setting is controlled by editing <code>php.ini</code>, Apache/IIS <br />configuration or <code>.htaccess</code> file on the server.</p>';
+$string['favicon'] = 'Favicon';
+$string['favicon_desc'] = 'Favicon file to be displayed as site icon';
 $string['feedbacksettings'] = 'Feedback settings';
 $string['filescleanupperiod'] = 'Clean up trash pool files';
 $string['filescleanupperiod_help'] = 'How often trash pool files are deleted. These are files that are associated with a context that no longer exists, for example when a course is deleted. Please note: This setting can result in missing files in a course which is backed up, deleted and then restored if the setting \'Include files\' (backup_auto_files) in \'Automated backup settings\' is disabled.';
diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index a3c536fa80c..f5c11f65870 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -4266,7 +4266,15 @@ EOD;
      * @return moodle_url The moodle_url for the favicon
      */
     public function favicon() {
-        return $this->image_url('favicon', 'theme');
+        global $CFG;
+        $logo = get_config('core_admin', 'favicon');
+        if (empty($logo)) {
+            return $this->image_url('favicon', 'theme');
+        }
+
+        // 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);
     }
 
     /**
diff --git a/theme/upgrade.txt b/theme/upgrade.txt
index c2fa7046373..efa852ad9e1 100644
--- a/theme/upgrade.txt
+++ b/theme/upgrade.txt
@@ -4,6 +4,7 @@ information provided here is intended especially for theme designer.
 === 4.1 ===
 * The function core_course_renderer::course_modchooser() has been finally deprecated and can not be used anymore.
   Please use core_course_renderer::course_activitychooser() instead.
+* $OUTPUT->favicon() now returns the URL of the configurable favicon if present.
 
 === 4.0 ===
 * A new theme config 'removedprimarynavitems' allows a theme to customise primary navigation by specifying the list of items to remove.