Question

There is related question about processing $http in a service, but I wanted to elaborate slightly. I would like my controller to be able to execute service calls using API similar to the Angular $http API:

$scope.login = function(user) {
  securityService.login(user).success(function(data) {
    $scope.data = data;
  }).error(function(data) {
    $scope.error = data;
  });
};

That’s a nice readable API. On the surface, all I would need to do in the service API is:

return {
  name : 'User Service',
  login : function(user) {
    return $http.post("/api/login", user);
  }
};

Great, it returns the promise and the success and error messages come with. But… What if I want to deal with the success and failure cases in the service? I want to maintain the nice, readable service API. In this case, maybe I’d want to preserve the user so that I could expose methods like securityService.currentUser() or `securityService.isLoggedIn()’.

I tried the $http.post().then(...) promise API, but those return the entire HTTP response. Again, I want to isolate HTTP to the services and maintain a similar concrete callback API.

Answer 1

You could make your own promise in login using angular’s $q:

var deferred = $q.defer(), 
    promise = deferred.promise;

$http.post("/api/login", user).success(...).error(...)

return promise;

Within the success/failure of the $http promise in your service, resolve/reject your deferred object.

Edit:

Expanding upon the $http.post:

$http.post("/api/login", user).success(function(data) {
  if (data == "foo") { // success case?
    deferred.resolve('you logged in!');
  } else {
    deferred.reject('something really bad happened!');
  }
})