How can I make HandleErrorAttribute work with Ajax?

Question

In my ASP.NET MVC 2 application I use HandleErrorAttribute to display a custom error page in case of unhandled exceptions, and it works perfectly unless the exception happen

Answer 1

To achieve this you could write a custom action filter:

public class AjaxAwareHandleErrorAttribute : HandleErrorAttribute
{
    public string PartialViewName { get; set; }

    public override void OnException(ExceptionContext filterContext)
    {
        // Execute the normal exception handling routine
        base.OnException(filterContext);

        // Verify if AJAX request
        if (filterContext.HttpContext.Request.IsAjaxRequest())
        {
            // Use partial view in case of AJAX request
            var result = new PartialViewResult();
            result.ViewName = PartialViewName;
            filterContext.Result = result;
        }
    }
}

And then specify the partial view to be used:

[AjaxAwareHandleError(PartialViewName = "~/views/shared/error.ascx")]
public class HomeController : Controller
{
    public ActionResult Index()
    {
        return View();
    }

    public ActionResult SomeAction() 
    {
        throw new Exception("shouldn't have called me");
    }
}

And finally in your view assuming you have the following link:

<%= Ajax.ActionLink("some text", "someAction", new AjaxOptions { 
    UpdateTargetId = "result", OnFailure = "handleFailure" }) %>

You could make the handleFailure function to update the proper div:

<script type="text/javascript">
    function handleFailure(xhr) {
        // get the error text returned by the partial
        var error = xhr.get_response().get_responseData();

        // place the error text somewhere in the DOM
        document.getElementById('error').innerHTML = error;
    }
</script>