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