Need help to understand async calls in angular js - angularjs

Question

I have a main controller and nested controllers within it. In the main controller I have defined object by async query to the service, and try to use the object in the nested controller. But in the object in the nested controller is empty, cause it fires before it will be updated in the main controller.
As I understand, asyncronous query should updates the scope after data obtain?
.controller('MainController', ['$scope', function($scope) {
$scope.uData = {};
$scope.uDataCurrent = {};
$scope.usersData = usersFactory.getUsersData().query(
function(response) {
$scope.uData = response;
$scope.uDataCurrent = $filter('filter')($scope.uData, {'user':$scope.myuser});
$scope.uDataCurrent = $scope.uDataCurrent[0];
},
function(response) {
$scope.message = "Error: "+response.status + " " + response.statusText;
});
})]
.controller('NestedController', ['$scope', function($scope) {
console.log($scope.uDataCurrent); // returns empty object
}])
Service:
.service('usersFactory', ['$resource', 'baseURL', function($resource,baseURL) {
this.getUsersData = function(){
return $resource(baseURL+"/index.php?app=users&format=raw&resource=user",null, {'update':{method:'PUT' }});
};
}])

Answer 1

You could use $scope.$watch.
angular.module("App", [])
.controller("OuterCtrl", ["$scope", "$timeout", function($scope, $timeout) {
$scope.users = null;
$timeout(function() {
$scope.users = ["John", "Jack"];
}, 500);
}]).controller("InnerCtrl", ["$scope", function($scope) {
$scope.changeCount = 0;
// TODO: Bad practice to rely on outer scopes here as its not enforced
// to have an OuterCtrl scope as parent scope. In this example every
// occurrences of InnerCtrl is embedded in an OuterCtrl in the html
$scope.$watch("users", function(newValue, oldValue) {
// This code runs when the users array is changed
$scope.changeCount++;
});
}]);
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.7/angular.js"></script>
<div ng-app="App">
<div ng-controller="OuterCtrl">
<div ng-controller="InnerCtrl">
<div>Change count: {{changeCount}}</div>
<div>Users</div>
<div ng-hide="users"> Loading...</div>
<ul>
<li ng-repeat="name in users">{{name}}</li>
</ul>
</div>
</div>
</div>