Implement new delete_instance callback.

lib.php

@@ -63,15 +63,60 @@ function capquiz_update_instance(stdClass $capquiz) {
  *
  * @param int $cmid Course module id for the instance to be deleted
  */
-function capquiz_delete_instance(int $cmid) {
-    $capquiz = new capquiz($cmid);
-    if ($capquiz) {
-        $user = $capquiz->user();
-        if ($user) {
-            $quba = $user->question_usage();
-            \question_engine::delete_questions_usage_by_activity($quba->get_id());
+function capquiz_delete_instance($id) {
+    global $CFG, $DB;
+    require_once($CFG->dirroot . '/mod/capquiz/locallib.php');
+    if (! $capquiz = $DB->get_record('capquiz', array('id' => $id))) {
+        return false;
+    }
+    // Delete question usage from core question.
+    question_engine::delete_questions_usage_by_activities(new qubaids_for_capquiz($capquiz->id));
+    // Delete any dependent records here.
+    $records = array();
+    if($records = $DB->get_records('capquiz_question_list', array('capquiz_id' => $capquiz->id))) {
+        foreach($records as $record) {
+            $recordsquestion = $DB->get_records('capquiz_question', array('question_list_id' => $record->id));
+            foreach($recordsquestion as $recordquestion) {
+                if (! $DB->delete_records('capquiz_question_rating', array('capquiz_question_id' => $recordquestion->id))) {
+                    return false;
+                }
+            }
+            if (! $DB->delete_records('capquiz_question', array('question_list_id' => $record->id))) {
+                return false;
+            }
+        }
+    }
+    $records = array();
+    if($records = $DB->get_records('capquiz_user', array('capquiz_id' => $capquiz->id))) {
+        foreach($records as $record) {
+            if (! $DB->delete_records('capquiz_attempt', array('user_id' => $record->id))) {
+                return false;
+            }
+            if (! $DB->delete_records('capquiz_user_rating', array('capquiz_user_id' => $record->id))) {
+                return false;
+            }
         }
     }
+    if (! $DB->delete_records('capquiz', array('id' => $capquiz->id))) {
+        return false;
+    }
+    if (! $DB->delete_records('capquiz_question_list', array('capquiz_id' => $capquiz->id))) {
+        return false;
+    }
+    if (! $DB->delete_records('capquiz_user', array('capquiz_id' => $capquiz->id))) {
+        return false;
+    }
+    if (! $DB->delete_records('capquiz_question_selection', array('capquiz_id' => $capquiz->id))) {
+        return false;
+    }
+    if (! $DB->delete_records('capquiz_rating_system', array('capquiz_id' => $capquiz->id))) {
+        return false;
+    }
+    if (! $DB->delete_records('event', array('modulename' => 'capquiz', 'instance' => $capquiz->id))) {
+        return false;
+    }
+
+    return true;
 }
 
 /**

locallib.php

@@ -32,3 +32,20 @@
  */
 class capquiz_exception extends moodle_exception {
 }
+
+/**
+ * A {@link qubaid_condition} for finding all the question usages belonging to
+ * a particular capquiz.
+ *
+ * @author      sumaiya Javed <sumaiya.javed@catalyst.net.nz>
+ * @copyright   2023 Catalyst IT Ltd
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class qubaids_for_capquiz extends qubaid_join {
+    public function __construct($capquizid) {
+        $where = 'capquiza.capquiz_id = :quizaquiz';
+        $params = array('quizaquiz' => $capquizid);
+
+        parent::__construct('{capquiz_user} capquiza', 'capquiza.question_usage_id', $where, $params);
+    }
+}