public function render_json()
 {
     if (isset($_GET['ajax']) && isset($_GET['check_providers_internal_id']) && isset($_GET['providers_internal_id']) && isset($_GET['external_video_provider_id'])) {
         $result = VideoLibrary_DatabaseHelper::video_exists_in_external_videos_by_external_video_provider_id_and_providers_internal_id($_GET['external_video_provider_id'], $_GET['providers_internal_id']);
         echo '{ "result" : ';
         if ($result) {
             echo 'true';
         } else {
             echo 'false';
         }
         echo ' }';
     }
 }
 public function is_video_unique($external_video_provider_id, $providers_internal_id)
 {
     if (VideoLibrary_DatabaseHelper::video_exists_in_external_videos_by_external_video_provider_id_and_providers_internal_id($external_video_provider_id, $providers_internal_id)) {
         throw new VideoLibrary_VideoAlreadyExistsInDatabaseException();
     }
     return TRUE;
 }