protected function getUrlPattern($class = null)
    {
        $url       = '';
        $classname = is_null($class) ? $this->model->owner_type : $class;
        if (!class_exists($classname)) {
            return $url;
        }
        if ($this->hasMethod($classname, 'getPatternUrl')) {
            $url = $classname::getPatternUrl($this->model->owner_id, $this->model);
        }
        return $url;
    }