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