AngularJS承诺数组

Question

任何人都可以帮我一些Angular的承诺吗？我有以下函数应该接受一个文件对象数组,迭代它们,并上传每一个.在每次迭代期间,promise对象被推送到一个数组promises.在我的upload函数中,我有一个附加的cycle函数,在.then()所有的promise对象都已解析之前不应该调用它.我认为我的代码看起来是正确的,但它无法正常工作.图像上传,但是cycle(files).then()会立即调用,而不是一旦promises数组结算.

function upload(files) {
    var uploadCount = files.length;
    function cycle(files) {
        var promises = [];
        for (var i = 0; i < files.length; i++) {
            var deferred = $q.defer();
            promises.push(deferred);
            var file = files[i];
            Upload.upload({
                url: '/photos.json',
                file: file
            }).success(function(){
                $scope.progressCurrentCount += 1;
                deferred.resolve();
            });
        };
        return $q.all(promises);
    };

    cycle(files).then(function(result) {
        if(uploadCount > 1) {
            $scope.lastAction = 'uploaded ' + uploadCount + ' photos';
        } else {
            $scope.lastAction = 'uploaded ' + uploadCount + ' photo';
        }
        $scope.showSuccessModal = true;
        $scope.uploading = false;
        $scope.failedUploads = [];
        $scope.newPhotos = {
            token: $scope.token,
            files: undefined
        };
        photoUploadBtn.removeClass('disabled');
    })
};

最终工作代码*

而不是设置var deferred = $q.defer();推deferred.promise入promises数组,然后解析deferred我的.success()回调,这是无效的,我只是在Upload.upload()没有.success()回调的情况下推送我的函数promises,然后将其传递给$q.all(),这将完成所有提升.

function upload(files) {
    var uploadCount = files.length;
    function cycle(files) {
        var promises = [];
        for (var i = 0; i < files.length; i++) {
            var file = files[i];
            var promise = Upload.upload({
                url: '/photos.json',
                file: file
            });
            promises.push(promise);
        };
        return $q.all(promises);
    };

    cycle(files).then(function(result) {
        if(uploadCount > 1) {
            $scope.lastAction = 'uploaded ' + uploadCount + ' photos';
        } else {
            $scope.lastAction = 'uploaded ' + uploadCount + ' photo';
        };
        $scope.showSuccessModal = true;
        $scope.uploading = false;
        $scope.failedUploads = [];
        $scope.newPhotos = {
            token: $scope.token,
            files: undefined
        };
        photoUploadBtn.removeClass('disabled');
        getPhotos(q);
    })
};

Answer 1

你必须将一个promise,而不是deferred,推送到promises数组:

promises.push(deferred.promise);

如果您这样考虑它会有所帮助:

• promise是您想要返回给消费者的只读对象
• 延迟是该只读承诺的修饰符,您希望自己保留它