/**
  * Checks if a file belongs to an item.
  *
  * @param File $file File to check.
  *
  * @return boolean
  */
 protected function _checkItemFile($file)
 {
     // Get the item.
     $item = $file->getItem();
     // Check if the found file belongs to the item.
     if (!empty($this->_item_identifier)) {
         // Get the item identifier.
         $item_identifier = $this->view->getRecordIdentifier($item, false);
         // Check identifier and id of item.
         if (strtolower($this->_item_identifier) != strtolower($item_identifier) && $this->_item_identifier != $item->id) {
             return false;
         }
     }
     return true;
 }