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

IMHO, @jessegavin 's decoration of $q is not perfect, it shouldn't return origin promise in success&error function. It will lose feature of flatten the callback pyramid.

And it can't split response data to success&error function $httpPromise dose.

for example

//can't do this..
somePromise.success(function(){
  return $http.get(...)//another primise
}).success(function(data){
  //data from $http.get..
})

Here is my version, it will recognize http response and will return the next promise. Make your own $q have the same behavior like $httpPromise

$provide.decorator('$q', function($delegate) {
  function httpResponseWrapper(fn) {
    return function(res) {
      if (res.hasOwnProperty('data') && res.hasOwnProperty('status') && res.hasOwnProperty('headers') && res.hasOwnProperty('config') && res.hasOwnProperty('statusText')) {
        return fn(res.data, res.status, res.headers, res.config, res.statusText);
      } else {
        return fn(res);
      }
    };
  };
  function decorator(promise) {
    promise.success = function(fn) {
      return decorator(promise.then(httpResponseWrapper(fn)));
    };
    promise.error = function(fn) {
      return decorator(promise.then(null, httpResponseWrapper(fn)));
    };
    return promise;
  };
  var defer = $delegate.defer;
  $delegate.defer = function() {
    var deferred = defer();
    decorator(deferred.promise);
    return deferred;
  };
  return $delegate;
});