Cannot download video from youtube vimeo

My yii action




        public function actionCreate()

        {

            $model = new Video();

    

            $uploaded = false;

    

            switch (Yii::$app->request->isAjax) {

                case "youtube":

                    $model->name = Yii::$app->request->post('name');

                    $model->url = str_replace("watch?v=", "embed/", Yii::$app->request->post('youtube'));

                    break;

                case "vimeo":

                    $model->name = Yii::$app->request->post('name');

                    $model->url = Yii::$app->request->post('vimeo');

                    break;

                case 'vk':

                    $model->name = Yii::$app->request->post('name');

                    $model->url = Yii::$app->request->post('vk');

                    break;

                default :

                    new InvalidParamException('Not valid data', 400);

            }

            if ($model->load($_POST)) {

    

                $file = UploadedFile::getInstance($model, 'file');

    

                if ($model->validate()) {

                    $uploaded = $file->saveAs(Video::UPLOAD_DIR);

    

                }

            }

            

    

            if ($uploaded) {

                return $this->redirect('index');

            }else{

                return new ServerErrorHttpException('we cannot uplkoad your video ',500);

            }

        }



My angular controller


    

    'use strict';

    

    main.controller('VideosController', function ($scope, $routeParams, appService)

    {

        var video; 

        $scope.save = function () {

            if ($scope.video) {

                appService.postData('index.php/site/create', $scope.video).then(function (data)

                {

                        $scope.alert = { showAlert:true, msg: angular.fromJson(data).mesg, alertClass: 'success' };

                    },

                    function (error) {

                        alert("Can't download this video");

                    });

            } 

        };

    });



So what’s your problem?