public static function cancel($vpl, $userid) { $example = $vpl->get_instance()->example; $lastsub = $vpl->last_user_submission($userid); if (!$lastsub && !$example) { throw new Exception(get_string('nosubmission', VPL)); } if ($example) { $submission = new mod_vpl_example_CE($vpl); } else { $submission = new mod_vpl_submission_CE($vpl, $lastsub); } return $submission->cancelProcess(); }