public function delete_submission(stdclass $submission) {
        global $DB;

        $assessments = $DB->get_records('workshop_assessments', array('submissionid' => $submission->id), '', 'id');
        $this->delete_assessment(array_keys($assessments));

        $fs = get_file_storage();
        $fs->delete_area_files($this->context->id, 'mod_workshop', 'submission_content', $submission->id);
        $fs->delete_area_files($this->context->id, 'mod_workshop', 'submission_attachment', $submission->id);

        $DB->delete_records('workshop_submissions', array('id' => $submission->id));

        // Event information.
        $params = array(
            'context' => $this->context,
            'courseid' => $this->course->id,
            'relateduserid' => $submission->authorid,
            'other' => array(
                'submissiontitle' => $submission->title
            )
        );
        $params['objectid'] = $submission->id;
        $event = \mod_workshop\event\submission_deleted::create($params);
        $event->add_record_snapshot('workshop', $this->dbrecord);
        $event->trigger();
    }