Server side redirection after jquery ajax call in asp.net mvc 4

Question

I am sending login information from a jQuery AJAX call to an MVC 4 controller:

   $.post(url, data, function (response) {       if (response=='InvalidLogin') {           //show invalid login       }       else if (response == 'Error') {           //show error       }       else {           //redirecting to main page from here for the time being.           window.location.replace("http://localhost:1378/Dashboard/Index");       }    }); 

If the login is successful, I want to redirect a user from the server-side to the appropriate page on the basis of user type. If the login fails, a string is sent back to user:

    [HttpPost]     public ActionResult Index(LoginModel loginData)     {         if (login fails)         {             return Json("InvalidLogin", JsonRequestBehavior.AllowGet);         }         else         {              // I want to redirect to another controller, view, or action depending              // on user type.         }     } 

But there are problems:

1. If this method returns 'ActionResult', then I'm getting the error not all code paths return a value.

2. If I use 'void', I cannot return anything.

3. Even if I use 'void' with no return, I am failing to redirect to other controller or view due to asynchronous nature of jQuery AJAX calls.

Are there any techniques to handle such scenarios?

Answer 1

return usually returns from method without executing any further statements in it so else part is not needed. This way you will get rid of a problem #1.

As for redirecting why not return some kind of redirect command:

[HttpPost] public ActionResult Index(LoginModel loginData) {     if (login fails)     {         return Json(new {result = "InvalidLogin"}, JsonRequestBehavior.AllowGet);     }     return Json(new {result = "Redirect", url = Url.Action("MyAction", "MyController")}); } 

And then in javascript:

$.post(url, data, function (response) {   if (response.result == 'InvalidLogin') {       //show invalid login   }   else if (response.result == 'Error') {       //show error   }   else if (response.result == 'Redirect'){       //redirecting to main page from here for the time being.       window.location = response.url;   }  });