Question

Using an API controller in MVC4, when the controller action throws an exception, ELMAH does not log the error.

I think the problem is that MVC4 sets the HTTP status code to 500, and it returns the exception details in a JSON object, but it does not throw an unhandled exception so ELMAH never sees it.

How can I get ELMAH to capture all responses where the status code is not 200?

Answer 1

The anwser described before doesn’t work. I’ve tried on my test server and received an error (“The given filter instance must implement one or more of the following filter interfaces: IAuthorizationFilter, IActionFilter, IResultFilter, IExceptionFilter.”)

Then I realized what happened …. you are trying to add the custom filter to the MVC Global Filter (filters.Add(new ElmahHandledErrorLoggerFilter());)

To fix that, I’ve split the filter registration in GlobalFilter and HttpFilter

FilterConfig.cs

    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new HandleErrorAttribute());
    }

    public static void RegisterHttpFilters(HttpFilterCollection filters)
    {
        filters.Add(new ElmahHandledErrorLoggerFilter());
    }

Global.asax

    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    FilterConfig.RegisterHttpFilters(GlobalConfiguration.Configuration.Filters);

😉