kneerunjun/servicesControllers.md

## servicesControllers.md

      
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              servicesControllers.md
            
          
    Your controllers have manifestation but not the services

<body ng-app="myApp" ng-controller="mainController">
<!-- here you go the scope has the existence since the controller has manifestation -->
</body>
var myApp  = angular.module("myApp", []);
var mainController = myApp.controller("mainController", function($scope, myService){
  //scope has a purpose and that is to link the object model to the html there in the view
  myService.getFromServer($scope.id).then(function(){
    //handle the object that is thrown by resolve case
  }, function(){
    //handle the case that is thrown by reject case
  });
})
var myService = myApp.service("myService", function($http, $q){
  this.getFromServer = function(id){
    var deferred = $q.defer();
    $http.get(url).then(function(){
      //success of the server API call
      // HTTP 200 OK 
      deferred.resolve({});
    }, function(){
      //failure of the server API call
      deferred.reject({ErrorMessage:"your error message from the server"})
    })
    return deferred.promise
  }
})

Services have no manifestation they are just to contain some logic that is agnostic of the view / html but reusable across the controllers
Controllers can have $scope and that has attributes which in turn are manifested
While making API calls it is an  Aysnc operation and so it would involve promises
Promises are simple and have resolution and rejection