class ShopmodxLinkTag extends modLinkTag{
    
    public function process($properties= null, $content= null) {
        parent :: process($properties, $content);
//        if (!$this->_processed) {
            if (is_numeric($this->_content)) {
                $this->_output = $this->modx->shopModx->makeUrl($this->_content);
            }
            if (!empty($this->_output)) {
                $this->filterOutput();
                $this->cache();
                $this->_processed= true;
            }
//        }
        /* finally, return the processed element content */
        return $this->_output;
    }    
    
}