MDL-49828 timezones: improve settings performance

lib/adminlib.php

@@ -8997,3 +8997,83 @@ class admin_setting_php_extension_enabled extends admin_setting {
         return $o;
     }
 }
+
+/**
+ * Server timezone setting.
+ *
+ * @copyright 2015 Totara Learning Solutions Ltd {@link http://www.totaralms.com/}
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @author    Petr Skoda <petr.skoda@totaralms.com>
+ */
+class admin_setting_servertimezone extends admin_setting_configselect {
+    /**
+     * Constructor.
+     */
+    public function __construct() {
+        $default = core_date::get_default_php_timezone();
+        if ($default === 'UTC') {
+            // Nobody really wants UTC, so instead default selection to the country that is confused by the UTC the most.
+            $default = 'Europe/London';
+        }
+
+        parent::__construct('timezone',
+            new lang_string('timezone', 'core_admin'),
+            new lang_string('configtimezone', 'core_admin'), $default, null);
+    }
+
+    /**
+     * Lazy load timezone options.
+     * @return bool true if loaded, false if error
+     */
+    public function load_choices() {
+        global $CFG;
+        if (is_array($this->choices)) {
+            return true;
+        }
+
+        $current = isset($CFG->timezone) ? $CFG->timezone : null;
+        $this->choices = core_date::get_list_of_timezones($current, false);
+        if ($current == 99) {
+            // Do not show 99 unless it is current value, we want to get rid of it over time.
+            $this->choices['99'] = new lang_string('timezonephpdefault', 'core_admin',
+                core_date::get_default_php_timezone());
+        }
+
+        return true;
+    }
+}
+
+/**
+ * Forced user timezone setting.
+ *
+ * @copyright 2015 Totara Learning Solutions Ltd {@link http://www.totaralms.com/}
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @author    Petr Skoda <petr.skoda@totaralms.com>
+ */
+class admin_setting_forcetimezone extends admin_setting_configselect {
+    /**
+     * Constructor.
+     */
+    public function __construct() {
+        parent::__construct('forcetimezone',
+            new lang_string('forcetimezone', 'core_admin'),
+            new lang_string('helpforcetimezone', 'core_admin'), '99', null);
+    }
+
+    /**
+     * Lazy load timezone options.
+     * @return bool true if loaded, false if error
+     */
+    public function load_choices() {
+        global $CFG;
+        if (is_array($this->choices)) {
+            return true;
+        }
+
+        $current = isset($CFG->forcetimezone) ? $CFG->forcetimezone : null;
+        $this->choices = core_date::get_list_of_timezones($current, true);
+        $this->choices['99'] = new lang_string('timezonenotforced', 'core_admin');
+
+        return true;
+    }
+}