public function is_empty_area() {
        if ($child = $this->get_area_backup(0, '/', '.')) {
            if (!$child->is_empty_area()) {
                return false;
            }
        }
        if ($child = $this->get_area_intro(0, '/', '.')) {
            if (!$child->is_empty_area()) {
                return false;
            }
        }

        foreach ($this->areas as $area=>$desctiption) {
            if ($child = $this->get_file_info('mod_'.$this->modname, $area, null, null, null)) {
                if (!$child->is_empty_area()) {
                    return false;
                }
            }
        }

        return true;
    }