Angular 从 foreach 循环链接承诺

Question

我有一组照片文件需要上传到 Azure 云存储，我使用 foreach 循环调用上传，如下所示：

$scope.savetemplate = function () { 
     var imagePathsArray = [];

     $scope.filesimage = [];
     $scope.filesimage.push($scope.file1);
     $scope.filesimage.push($scope.file2);
     $scope.filesimage.push($scope.file3);


    for (var i in $scope.filesimage) {
        $scope.upload($scope.filesimage[i]);
    }


    $scope.data.Images = imagePathsArray ;

     $http({
              //after finish uploads i need to post the paths 
              //of all images to save into database
     })
 };


$scope.upload = function (file) {
  Upload.upload({
       url: '/uploadImage',
       data: { file: file }
    }).then(function (resp) {
       imagePathsArray.push(resp.data);

    })
};

resp.data returns 天蓝色存储路径，我需要将路径推入 imagePathsArray

我如何使用 Angular Promise 等待所有文件上传完成并且所有路径都存储在 imagePathsArray 中以便我可以继续

 $scope.data.Images = imagePathsArray ;

这样我就可以获取数组中的路径并执行 $http post?

Answer 1

上传成功回调中，推送路径后：

imagePathsArray.push(resp.data);
if(imagePathsArray.length == $scope.filesimage.length){
  pushtoDatabase();
}

在 pushtoDatabase 内调用 $http({ .... });

注意：您可能想考虑上传失败的可能性。在这种情况下，您可以使用失败文件的计数器来解决 failCounter ，然后在 if 检查条件

if ((imagePathsArray.length + failCounter) == $scope.filesimage.length){....}

Answer 2

你可以用 $q.all 来做到这一点。

var promises = [];
for (var i in $scope.filesimage) {
    promises.push(upload($scope.filesimage[i]));
}
$q.all(promises).then(function() {
    $scope.data.Images = imagePathsArray ;

    $http.post({
          //after finish uploads i need to post the paths 
          //of all images to save into database
    });
});

function upload(file) {
    return Upload.upload({
       url: '/uploadImage',
       data: { file: file }
    }).then(function (resp) {
       imagePathsArray.push(resp.data);
    })
};

Angular 从 foreach 循环链接承诺

Angular chaining promises from foreach loop

angularjs

azure

angular-promise

ng-file-upload