Is it possible to return a value from the success method of $http.get in AngularJS?

Question

I'm having a bit of a brainmelt with promises at the moment.

Given the following code:

$scope.getData = function(user) {

    return $http.post('/endpoint', "some post data", { headers: { 'Content-Type': 'application/x-www-form-urlencoded' } })
        .success(function (response) {

            var myThing = { stuff: response.infoData };

            localStorageService.set('myData', { stuff: response.infoData });

            return myThing;
    });
};

Is the myThing object that is returned from the success callback:

• returned as the result of the $scope.getData method, or
• ignored and lost to nowhere?

From what I understand:

• because $http.post is a promise, it resolves asynchronously and then runs the success method
• when the success method is run, it returns the myThing object but this doesn't magically replace the entire $http.post promise itself

Is this correct? Is there something I'm missing, is there some benefit to returning objects in the success method, or is the return superfluous? (I'm well aware that this is code can be improved but I'm trying to find out specifically why someone would have written this, or if it was entirely a mistake)

Answer 1

Using success/error callbacks over $http method wouldn't give you ability to return a data from it. Where as promise does provide that ability. The way it has written currently would do what it seems. Like myThing will not return by current implementation(that is redundant return statement there).

Why someone would have written this, or if it was entirely a mistake?

Whoever implemented this method was trying to return a data from it, but I don't think so he is succeeded in that by looking at current code.

To Take advantage of promise returned by $http method's which will give you capabilities to form promise chain over async call. For that you need to use .then instead of .success method.

$scope.getData = function(user) {
    return $http.post('/endpoint', "some post data", { headers: { 'Content-Type': 'application/x-www-form-urlencoded' } })
      .then(function (res) {
          var response = res.data;
          var myThing = { stuff: response.infoData };
          localStorageService.set('myData', { stuff: response.infoData });
          return myThing;
    });
};

If you really interested to retrieve data by calling getData method, then you could consume getData method you should put .then function over promise returned by it to chain it.

$scope.getData().then(function(thing){
    console.log(thing);
})

Side Note .success & error function over $http methods are deprecated .