How do you trigger the "error" callback in a jQuery AJAX call using ASP.NET MVC?

Question

This is related to my question on how to handle errors from jQuery AJAX calls. Several responses suggested that I use the "error" callback to display any errors from a jQuery AJAX call. I was wondering how to do that using ASP.NET MVC. Is there a way for my controller action to return an error that would be accessible from the "error" callback? The client side code would look something like this:

$.ajax({
   type: "POST",
   url: "MyUrl",
   data: "val1=test",
   success: function(result){
        // Do stuff
   },
   error: function(request,status,errorThrown) {

   }
 });

Answer 1

I think that event is raised for any response that has a response code other than 200. I can't find proof of this in the docs though.

To do this from code (works in Webforms):

throw new HttpException(500, "Error message");

Answer 2

According to this page, you just need to apply the header HTTP/1.0 500 Internal Server Error on your ASP.net page. The $.ajax request will catch that error and execute the error callback function. =]

Answer 3

Do something like this:

Response.StatusCode = (int)HttpStatusCode.BadRequest;
actionResult = this.Content("Error message here");

The status code should change depending on the nature of the error; generally, 4xx for user-generated problems and 5xx for server-side problems.

Answer 4

If you're using

[HandleError]

then throwing a HttpException is going to get caught and routed to your custom error page.

Another option is to use

Response.StatusCode = 500;
Response.Write("Error Message");
Response.End();

There's probably a more convenient way to write this but I haven't stumbled upon it yet.

Answer 5

http://api.jquery.com/ajaxError/

Answer 6

If you're using MVC 3, then you can return an ActionResult in your controller that has the HTTP status code and status message together:

return new HttpStatusCodeResult(500, "Error message");

Then, in your error callback:

error: function (request, textStatus, errorThrown) {
    alert(request.statusText);
}