Like many people using ASP.NET MVC, I've implemented my own custom 404 error handling scheme using an approach similar to the one described here: http://stackoverflow.com/questions/619895/how-can-i-properly-handle-404s-in-asp-net-mvc/2577095#2577095
(I actually discovered that post after implementing my own solution, but what I came up with is virtually identical.)
However, I ran into one issue I'm not sure how to properly handle. Here's what my 404 action in my ErrorController class looks like:
public ActionResult NotFound(string url)
{
url = (url ?? "");
if (Request.Url.OriginalString.Contains(url) &&
Request.Url.OriginalString != url)
{
url = Request.Url.OriginalString;
}
url = new Uri(url).AbsolutePath;
// Check URL to prevent 'retry loop'
if (url != "/Error/NotFound")
{
Response.StatusCode = (int)HttpStatusCode.NotFound;
// Log 404 error just in case something important really is
// missing from the web site...
Elmah.ErrorSignal.FromCurrentContext().Raise(
new HttpException(Response.StatusCode,
String.Format("Resource not found: {0}", url)));
}
return View();
}
The part that's different from the answer in the other StackOverflow question I referenced above is how the 'retry loop' is prevented. In other other answer, the code that prevents the retry loop simply sets properties on a ViewModel, which doesn't seem to actually prevent the loop. Since the action is sending back a response code of 404, then accessing the action directly (by typing "/Error/NotFound" in the browser) causes an infinite loop.
So here's my question: Did I miss another, more obvious way to handle the retry loop issue, or is my approach a decent way to do this?