Angular service/factory - class 属性 未在 cordova 文件传输中更新

Question

我有 Angular 在移动应用程序中执行 Cordova 文件传输上传的服务 - 它将文件上传到媒体服务器并 returns 一个对象。我正在尝试将此对象传递给 media_response 属性 但我运气不好 - 我做错了什么？

请注意 - 我已经尝试使用 service 和 factory，但似乎仍然没有任何乐趣 - $cordovaFileTransfer upload 块中的任何内容都不会传递给 class 一些奇怪的原因的属性。

我希望看到 media_response 具有与数据变量相同的输出，数据变量是从媒体服务器返回的对象，但它显示 no response

知道为什么我没有收到预期的回复吗？

// 预期响应

UploadService.media_response in the controller should be an object to match the console.log(data)

//实际响应

UploadService.media_response is the string 'no response'

//上传服务

abcdServices.service('UploadService', function($http, $localStorage, $location, $q, $rootScope, $cordovaFileTransfer) {

var UploadService = function() {
    this.upload_in_progress = false;
    this.progress = 0;
    this.media_response = '';
};

UploadService.prototype.cordovaFileUpload = function (filename, url, targetPath) {
    this.upload_in_progress = true;
    this.media_response = 'no response';

    var options = {
        id: new Date() . getTime()  + filename,
        fileKey: "file",
        fileName: filename,
        chunkedMode: false,
        mimeType: "multipart/form-data",
        params : {'fileName': filename}
    };

    $cordovaFileTransfer.upload(url, targetPath, options).then(
        function(result) {
            // Success!
            var data = JSON.parse(result.response);
            console.log('file uploaded - response:', data); // ALWAYS A OBJECT
            this.media_response = 'fake response2';
            UploadService.media_response = 'fake response3';

            if (angular.isDefined(data.id)) {
                angular.forEach(data, function(value, key) {
                    // image[key] = value;
                });
                // $scope.post.linkThumbnail = false;
                // $scope.post.video = '';
            } else if (angular.isDefined(data.message)) {
                // $scope.uploadError = data.message;

            } else {

            }
        }, function(err) {

        }, function (progress) {
            // constant progress updates
            this.progress = parseInt(100 * progress.loaded / progress.total) + '%';
        }
    );

};

return new UploadService();});

//控制器

UploadService.cordovaFileUpload(filename, url, targetPath, options);
console.log(UploadService); // to view in js console

Answer 1

您的 this. 变量的范围是最近的功能块，而不是 service/factory。

使用 var 或 let 在 service/factory 的根目录中创建变量。

---

abcdServices.service('UploadService', function($http, $localStorage, $location, $q, $rootScope, $cordovaFileTransfer) {

    let upload_in_progress = false;
    let progress = 0;
    let media_response = '';

    var UploadService = function() {
        upload_in_progress = false;
        progress = 0;
        media_response = '';
    };

    UploadService.prototype.cordovaFileUpload = function (filename, url, targetPath) {
        upload_in_progress = true;
        media_response = 'no response';

        // Rest of your code
    };

return new UploadService();});

---

如果你真的need/want要使用this，请使用新的函数箭头符号，它不会在函数块中创建新的this-作用域。

abcdServices.service('UploadService', function(...) {

    this.upload_in_progress = 'test';
    this.progress = 0;
    this.media_response = '';

    someFunction = (param1, param2, ..) => {
        console.log(this.upload_in_progress) // 'test'
    }

});