function delete_content($recordid=0) {
        global $DB;

        if ($recordid) {
            $conditions = array('fieldid'=>$this->field->id, 'recordid'=>$recordid);
        } else {
            $conditions = array('fieldid'=>$this->field->id);
        }

        $rs = $DB->get_recordset('data_content', $conditions);
        if ($rs->valid()) {
            $fs = get_file_storage();
            foreach ($rs as $content) {
                $fs->delete_area_files($this->context->id, 'mod_data', 'content', $content->id);
            }
        }
        $rs->close();

        return $DB->delete_records('data_content', $conditions);
    }