MDL-69400 mod_forum: Added calender event refreshing.

mod/forum/lib.php

@@ -7021,3 +7021,20 @@ function mod_forum_core_calendar_get_event_action_string(string $eventtype): str
         return get_string('requiresaction', 'calendar', $modulename);
     }
 }
+
+/**
+ * This callback will check the provided instance of this module
+ * and make sure there are up-to-date events created for it.
+ *
+ * @param int $courseid Not used.
+ * @param stdClass $instance Forum module instance.
+ * @param stdClass $cm Course module object.
+ */
+function forum_refresh_events(int $courseid, stdClass $instance, stdClass $cm): void {
+    global $CFG;
+
+    // This function is called by cron and we need to include the locallib for calls further down.
+    require_once($CFG->dirroot . '/mod/forum/locallib.php');
+
+    forum_update_calendar($instance, $cm->id);
+}