- $chatid = get_coursemodule_from_id('chat', $context->instanceid, 0, false, MUST_EXIST)->instance;
+ $cm = get_coursemodule_from_id('chat', $context->instanceid);
+ if (!$cm) {
+ return;
+ }
+
+ $chatid = $cm->instance;
$DB->delete_records_select('chat_messages', 'chatid = :chatid', ['chatid' => $chatid]);
$DB->delete_records_select('chat_messages_current', 'chatid = :chatid', ['chatid' => $chatid]);
$DB->delete_records_select('chat_users', 'chatid = :chatid', ['chatid' => $chatid]);
$DB->delete_records_select('chat_messages', 'chatid = :chatid', ['chatid' => $chatid]);
$DB->delete_records_select('chat_messages_current', 'chatid = :chatid', ['chatid' => $chatid]);
$DB->delete_records_select('chat_users', 'chatid = :chatid', ['chatid' => $chatid]);