Question

I have html.actionlink in my asp.net MVC 3view and jquery ajax call on link click. In my action method suppose I have this:

 if (a == 2) //return ok 
                return Json(new { Error = "false", Message = "Everything ok" }, JsonRequestBehavior.AllowGet);
            else
                return Content("");

Ajax call is:

$(function () {
    $('#checkExists').click(function () {
        $.ajax({
            url: $('#checkExists').attr('href'),
            global: true,
            type: 'GET',           
            timeout: 5000,
            success: function (data) { //invoke when receive response from server                             

                if (data != null && data.Error != '') //return failed
                {
                    alert(data.Error);
                }
//                else {
//                    alert('error occurs 1');
//                    //action ok here
//                }
            },
          error: function (xhr, ajaxOptions, thrownError) {
              alert(xhr + ajaxOptions +  "Cannot connect to server to load data"); //sever is not available                 
            },
            complete: function () { //ajax done
                //alert('complete');
            }
        });
        return false;
    });

In case of else , ajax i called, how can I stop $.ajax call ?

Answer 1

you have already made the ajax call there is no way you can undo it in your current scenario

what you can do is send a doNothing response

 if (a == 2) //return ok 
                return Json(new { Error = "false", Message = "Everything ok" }, JsonRequestBehavior.AllowGet);
            else
                return Json(new { Message = "do nothing" }, JsonRequestBehavior.AllowGet);

and in the ajax success callback

success:function(data){
if(data.Message==='do nothing'){
// simply do nothing
}
}

jsut as a side note you can cancel the ajax call before you have instantiated it see this SO answer Abort Ajax requests using jQuery

update

if (a == 2) //return ok 
                return Json(new { Error = "false", Message = "Everything ok" }, JsonRequestBehavior.AllowGet);
            else
                return Content("");

and in the success callback

success:function(data){
if(!data.Message)
//alert(data); //content will be shown
}