Chaining array of promise returning functions with $q

Question

I have an array of functions, where each function returns promise from ajax call.

var promises = [];
if (form.$valid) { 
  Object.keys($scope.Model.Data.FormFiles).forEach(function (key) {
    var file = $scope.Model.Data.FormFiles[key];

    function uploadFile(){
        var deferred = $q.defer();
        var upload = Upload.upload({
            url: "/api/ir/funnelApi/UploadFile",
            data: { file: file }
        });

        upload.then(function (response) {                           
                // do something
                deferred.resolve(response.statusText);
            }, function (error) {
                deferred.reject(error.data);
            }, function (evt) {

        });             
        return deferred.promise;
    }       

    promises.push(uploadFile);
  });   
}

What i am trying to do is, if all the file has been uploaded successfully then do something.

$q.all(promises).then(function (responses) {                    
   // do something
}, function (errors) {
   // if any of the file upload fails, it should come here  
});

But the problem is the ajax are never fired and the $q.all always moves to success with the function array.

What's the wrong i am doing??

does it get inside `deferred.resolve(response.statusText);`? try putting `console.log()` there — Max Koretskyi, Dec 27 '16 at 06:56
For this to work the parent promise has to be resolved or rejected, can you post the Ajax request code — Aravind.HU, Dec 27 '16 at 06:57
It seems the uploadFile function is not called from anywhere. You need to call that function. — Paulson Peter, Dec 27 '16 at 06:57

score 5 · Accepted Answer · edited May 23 '17 at 11:53

5

You are pushing references of the function to array....not invoking the function and pushing the returned promise

Try changing:

promises.push(uploadFile);

to

promises.push(uploadFile());

Creating a new promise using $q.defer(); is also an antipattern when Upload.upload() already returns a promise and you could simply return that instead

edited May 23 '17 at 11:53

Community

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answered Dec 27 '16 at 06:58

charlietfl

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Chaining array of promise returning functions with $q

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