/** * Finds the Libro model based on its primary key value. * If the model is not found, a 404 HTTP exception will be thrown. * @param integer $id * @return Libro the loaded model * @throws NotFoundHttpException if the model cannot be found */ protected function findModel($id) { if (($model = Libro::findOne($id)) !== null) { return $model; } else { throw new NotFoundHttpException('The requested page does not exist.'); } }