How to use a function defined in a controller in another controller in angularjs

Question

I have 2 controllers, loginCtrl and regCtrl, there is a function inside the login controller $scope.login and i want to call this function from inside my regCtrl. What i am trying to achieve is to redirect an user to his homepage without need for login after successful registration. Login function in loginCtrl

 $scope.login=function(){
        NProgress.start();
        singInClicked = true;
        var request =$http({
              withCredentials: true,
              method:"post",
              url: "http://localhost:1337/auth/login",
              data: {
                    user_identifier: $scope.user_identifier,
                    password: $scope.password
              }
        });
and the code of the regCtrl where i want to call this function is 

request.success(
        function(data){
            $scope.response=data;
            console.log("you have registered successfully");
            //serviceStatus($http);
            //**call $scope.login here**
            NProgress.done();
        });

How do i achieve this?

Answer 1

One way would be to inject a $controller service in your reg controller, assign a new scope while creating the $controller and use that scope to call the function on loginCtrl.

app.controller('regCtrl', ['$scope', '$controller', function($scope, $controller) {

    var loginCtrlVM = $scope.$new(); //Create a new scope
    //var loginCtrlVM = $scope.$new(true);  //Or even an isolated scope

    $controller('loginCtrl', {$scope:loginCtrlVM }); //Instantiate loginCtrl passing in the scope

     request.success(function(data){
        ...
        console.log("you have registered successfully");

        loginCtrlVM.login(); //<--- Now call login from your own scope

        NProgress.done();
    });

}]);

---

Another way would be abstract out the logic to a separate service and use it in both the controllers, or even in a common route logic which checks if the user has logged in (Your registration service can perform login action as well by calling the login service to set the logged in status). This way you dont have to have this kind of dependency in your controllers. It also seems like you have NProgress.start(); in one controller and NProgress.done(); in a different controller (probably i have not see the whole code) which makes it look spaghetti.