$http in Anjgularjs: Can someone explain the flow

Question

In an $http call, What all things we can pass in the url part, I have a server address, a user name and Password. Can i pass all as a json object?, or we have any other parameter (like url) for this.? Can someone help me in understanding what is happening on a success call.

Specifically, the code I'm struggling with is:

app.factory('myFactory',function(){

var fact = {};
fact.getData = function(a){
    $http({method:'POST',url:'http://100.100.100.100:8080/xx/xx.xx'});
    $http.success(function(reply){a(reply)}
        );
};

return fact;

});

---

See the following code, still I am not getting data from server, at the same time no errors too.

xapp.factory('loginData',function($http,$log){
    var fact = {};

    fact.getData = function(cred,cb){
        return
            $http({
                method:'post',
                url:'xxx.xxx.xxx.xxx:xxxx/xxxxxx',
                data:cred})
            .success(function(data,status,header,config){
                cb(data);
                })
            .error(function(data,status,header,config){
                $log.warn(status);
                });
    };

    return fact;
});


xapp.controller('mainController',function($scope,$log,$http,loginData){
    $scope.user = {uesr:'user',password:'123'};

    loginData.getData($scope.user,function(data){
        $scope.reply = data;
        });
});

In the console log, I get an 'undefined'. If the http url is correct, do u see any issue?

Answer 1

As far as I understand, a parameter is a callback function that is executed when reply from server is received. This kills the purpose of promises that the $q service provides. Also, $http service itself does not have .success callback. It returns a promise object with .success and .error callbacks. Here's how it should be done:

app.factory('myFactory', function() {
  var fact = {};
  fact.getData = function() {
    return $http.get('your/path/to/resource/');
  }
  return fact;
})
.controller('myCtrl', function($scope, myFactory) {
  myFactory.getData().then(function(response){
    //response.data holds your data from server
  }, function(){
    //this fn gets called when error happens
  });
});

Some explanations: myFactory.getData() creates a new http request to the server and returns a promise object which has a method .then(successCallback, errorCallback). You can provide callbacks to the promise to be executed after request is complete.

You might get confused with my mentioned .then(successCallback, errorCallback) and .success(callback) used in your example. A generic promise that $q provides has .then method, but $http service, upon returning a promise, provides shortcuts .success() and .error() but it's the same thing in the end.