Question

I was wondering what the best implementation for a global error (doesn’t have to be errors, can also be success messages) handler would be? Let me break it down for you with an example:

1. User tries to delete a record
2. Deletion fails and an error is logged
3. User redirects to another page
4. Display error message for user (using a HtmlHelper or something, don’t want it to be a specific error page)

I’m just curious what you guys think. I’ve been considering TempData, ViewData and Session but they all have their pros and cons.

TIA!

UPDATE:

I’ll show an example what I exactly mean, maybe I wasn’t clear enough.
This is an example of a method that adds a message when user deletes a record.
If user succeeds, user redirects to another page

public ActionResult DeleteRecord(Record recordToDelete)
{
    // If user succeeds deleting the record
    if (_service.DeleteRecord(recordToDelete) 
    {
        // Add success message
        MessageHandler.AddMessage(Status.SUCCESS, "A message to user");

        // And redirect to list view
        return RedirectToAction("RecordsList");
    }
    else 
    {
        // Else return records details view
        return View("RecordDetails", recordToDelete);
    }
}

And in the view “RecordsList”, it would be kinda cool to show all messages (both error and success messages) in a HtmlHelper or something.

<%= Html.RenderAllMessages %>

This can be achieved in many ways, I’m just curious what you guys would do.

UPDATE 2:

I have created a custom error (message) handler. You can see the code if you scroll down.

Answer 1

I’m confused by these steps:

• Deletion fails and an error is logged
• User redirects to another page

Why would you redirect the User when an error occurs? That doesnt make any sense, unless im misunderstanding something.

Generally, i follow these guidelines:

• Error with form submission (e.g HTTP POST): check ModelState.IsValid and return the same View and render the error out with @Html.ValidationSummary()
• Error with AJAX call: return JsonResult (like @Tomas says), and use basic client-side scripting to inspect the JSON and show the result
• Error with domain/business: throw custom exceptions and let the controller catch them and add to ModelState as above