/**
  * Render the form.
  *
  * @return string
  * @api
  */
 public function render()
 {
     $categories = array();
     if ($this->arguments['categoryArr'] !== NULL) {
         foreach ($this->arguments['categoryArr'] as $categoryId) {
             $category = $this->newsCategoryRepository->findByIdentifier($categoryId);
             if ($category !== NULL) {
                 $categories[] = $category;
             }
         }
     }
     $this->templateVariableContainer->add($this->arguments['as'], $categories);
     return $this->renderChildren();
 }