RedirectRouteHandler

Continuing in the same topic as the languagehandler, this RouteHandler allows you to define ‘shortcuts’ outside of the Routing system (for instance in a database). To use it, you add a catch-all route with this RoutHandler (preferrably in conjunction with a special controller to handle 404’s).

IShortCutProvider shortCutProvider = ...;

Route possible404 = new Route(
    "*",
    new RouteValueDictionary(
        new { controller = "fault", action = "404" }
    ),
    new RedirectRouteHandler(shortCutProvider)
);

routes.Add(possible404);

Uses a simple interface to check for available shortcuts.

using System;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;

namespace austrheim
{
    public class RedirectRouteHandler : MvcRouteHandler
    {
        private IShortCutProvider _shortCutProvider;

        public RedirectRouteHandler(IShortCutProvider shortCutProvider)
        {
            _shortCutProvider = shortCutProvider;
        }

        protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
        {
            string newUrl;

            if (_shortCutProvider.TryGetShortCut(requestContext.HttpContext.Request.Url, out newUrl))
            {
                return new RedirectHandler(newUrl);
            }

            return base.GetHttpHandler(requestContext);
        }
    }

    public interface IShortCutProvider
    {
        bool TryGetShortCut(Uri requestUri, out string newUrl);
    }

    public class RedirectHandler : IHttpHandler
    {
        private string newUrl;

        public RedirectHandler(string newUrl)
        {
            this.newUrl = newUrl;
        }

        public bool IsReusable
        {
            get { return true; }
        }

        public void ProcessRequest(HttpContext httpContext)
        {
            httpContext.Response.StatusCode = 301;
            httpContext.Response.RedirectLocation = newUrl;
        }
    }
}

When a url is entered that does not match any routes, it will trickle down to the catch-all route.

The catch-all route then checks if a shortcut is found, and the viewer will be redirected to the shortcuts destination.