/**
  * Execute action
  *
  * @param string $action
  * @return null
  */
 function execute($action)
 {
     if ($this->request->isApiCall() && !in_array($this->request->getAction(), $this->api_actions)) {
         $this->httpError(HTTP_ERR_FORBIDDEN, null, true, true);
     }
     // if
     $execute = parent::execute($action);
     if (is_error($execute)) {
         return $execute;
     }
     // if
     if ($this->getAutoRender()) {
         $render = $this->render();
         if (is_error($render)) {
             return $render;
         }
         // if
     }
     // if
     return true;
 }