Question

I am working on an e-commerce site and I need google sign-on it, so when a user creates his/her shopping list and click on the add to list button. I am able to send my data through the $.ajax() method, so what I exactly want is when the response from ajax method come it should redirect me to Login page if the user is not logged in, else it should save my object.

Answer 1

In the target endpoint of that .ajax() call, check your authentication, and if the user is not logged in, set the response header to – 401 Unauthorized.

Then in the .ajax() do this:

$.ajax(function() {
   //.. your other ajax stuff..//
   error: function(jqXHR, textStatus, errorThrown) {
      // only redirect if user unauthorized - 'errorThrown' has text part of HTTP status header
      if(errorThrown == "Unauthorized") {
          window.location.href = "myloginpage.html";
      }
   }
});

The response header being set to 401 will trigger .ajax()’s error function, instead of the success function.

Edit:
Changed the error function to only redirect on Unauthorized

Also note, that if this is a cross-domain jsonp call, it won’t work, as jsonp requests fail silently and don’t trigger the error function