/**
  * Generate thumbnail URL from file dataobject (if available)
  *
  * @return string
  */
 protected function getFilePreviewURL()
 {
     // Get preview from file
     if ($this->file) {
         $width = $this->config()->media_preview_width;
         $height = $this->config()->media_preview_height;
         return $this->file->ThumbnailURL($width, $height);
     }
 }