How can I extend $q promise in Angularjs with a .success and .error

Question

I wrote this little code in a custom service in AngularJS.

In my service:

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


        

Answer 1

If you want to change the default behavior of something that is injected by angular, you can use the decorator() method on the $provide service.

var myApp = angular.module("myApp", []);

myApp.config(function ($provide) {
  $provide.decorator("$q", function($delegate) {
    // The $delegate argument here refers to the $q service.

    $delegate.defer = function() {
      alert("You just tried to call defer()!");
    };

    // Now, every time angular provides an instance of $q via
    // injection, it will return your customized version of $q.

    return $delegate;
  });
});

See the example above in action at http://plnkr.co/edit/RuZF2cGkVHwlu7NIhxEZ?p=preview

As to modifying $q to add the success and error functions, I am not sure at the moment. But I am pretty sure that this is where you'd want to do it.