angularJS: Error: $scope is not defined - angularjs

Question

I want to run a service that read total unread message when user visits a few particular page. I'm using resolve for this. I set up a factory which communicates with the backend through a http call and the backend returns the count of total messages and I wanna show this in html page but all I am getting is error.
( function () {
var countAllUnreads = function($location, $q, AuthService3)
{
var deferred = $q.defer();
AuthService3.fetchUnreadNotifications().then(function (res)
{
console.log('this is me');
$scope.numOfNotifications =res.data.totalUnread;
});
}
angular.module('myApp', [
'ngRoute',
'myApp.login',
'myApp.home',
'myApp.directory',
'myApp.forgotpassword',
'myApp.myProfile',
])
.factory('AuthService3', ["$http", "$location", function($http, $location){
var baseUrl = 'api/';
var fetchUnreadNotifications = function()
{
return $http.post(baseUrl + 'getAllUnreadNotifications');
}
return {fetchUnreadNotifications: fetchUnreadNotifications} ;
}])
.config(['$routeProvider', function($routeProvider) {
$routeProvider
.when('/login', {
controller: 'LoginController',
templateUrl: 'app/components/login/loginView.html',
controllerAs: 'vm'
})
.when('/forgotpassword', {
controller: 'ForgotpasswordController',
templateUrl: 'app/components/forgotpassword/forgotpasswordView.html',
controllerAs: 'vm'
})
.when('/directory/:directoryType', {
controller: 'DirectoryController',
templateUrl: 'app/components/directory/directoryView.html',
resolve: {notifications:countAllUnreadsn,},
controllerAs: 'vm'
})
.when('/home', {
controller: 'HomeController',
templateUrl: 'app/components/home/homeView.html',
resolve: {notifications:countAllUnreadsn,},
controllerAs: 'vm'
})
.when('/myprofile', {
controller: 'MyProfileController',
templateUrl: 'app/components/profile/myProfileView.html',
resolve: {notifications:countAllUnreadsn,},
controllerAs: 'vm'
})
.otherwise({
redirectTo: '/login'
});
}]);
})();

Answer 1

The problem is that you are using $scope within the function which loads notifications. $scope will not be available there since it might not be created yet. You need to return a promise and the resolved value can be injected as a dependency to the controller.
var countAllUnreads = function($location, $q, AuthService3)
{
var deferred = $q.defer();
AuthService3.fetchUnreadNotifications().then(function (res)
{
deferred.resolve(res.data.totalUnread);
});
return deferred.promise;
};
And in your controllers, have a dependency for 'notifications'.
Ex: function HomeController($scope, $http, notifications){ }