ASP.NET MVC: Redirect from query string params to a canonical url

Question

In my Asp.Net Mvc project I'd like to have a good looking urls, eg mysite.com/Page2, and I want to redirect from my old style urls (such as mysite.com?page=2) with 301 state so that there won't be two urls with identical content. Is there a way to do it?

As far as I know Asp.Net binding framework doesn't make difference between query string and curly brace params

Answer 1

I am not sure, I got your question right. It seems, your current setup relies on those GET parameters (like mysite.com?page=2). If you dont want to change this, you will have to use those parameters further. There would be no problem in doing so, though. Your users do not have to use or see them. In order to publish 'new style URLs' only, you may setup a URL redirect in your web server. That would change new style URLs to old style URLs.

The problem is the 301. If the user requests an old style URL, it would be accepted by the webserver as well. Refusing the request with a 301 error seems hard to achieve for me.

In order to get around this, I guess you will have to change your parameter scheme. You site may still rely on GET parameters - but they get a new name. Lets say, your comments are delivered propery for the following (internal) URL in the old scheme:

/Article/1022/Ms-Sharepoint-Setup-Manual?newpage=2

Note the new parameter name. In your root page (or master page, if you are using those), you may handle the redirect permanent (301) manually. Therefore, incoming 'old style requests' are distinguishable by using old parameter names. This could be used to manually assemble the 301 in the response in ASP code.

Personally, I would sugesst, to give up the 301 idea and just use URL redirection.

Answer 2

Well, as far as I can see performing such redirection in ASP.NET MVC might be tricky. This is how I did it:

global.asax:

        routes.Add(new QueryStringRoute());

        routes.MapRoute(null, "Article/{id}/{name}",
            new { controller = "Article", action = "View", page = 1 },
            new { page = @"\d+" }
        );

        routes.MapRoute(null, "Article/{id}/{name}/Page{page}",
            new { controller = "Article", action = "View" },
            new { page = @"\d+" }
        );

QueryStringRoute.cs:

public class QueryStringRoute : RouteBase
{
    private static string[] queryStringUrls = new string[]
    {
        @"~/Article/\d{1,6}/.*?page=\d{1,3}"
    };


    public override RouteData GetRouteData(HttpContextBase httpContext)
    {
        string url = httpContext.Request.AppRelativeCurrentExecutionFilePath;

        foreach (string queryStringUrl in queryStringUrls)
        {
            Regex regex = new Regex(queryStringUrl);
            if (regex.IsMatch(url))
            {
                long id = 0; /* Parse the value from regex match */
                int page = 0; /* Parse the value from regex match */
                string name = ""; /* Parse the value from regex match */

                RouteData rd = new RouteData(this, new MvcRouteHandler());

                rd.Values.Add("controller", "QueryStringUrl");
                rd.Values.Add("action", "Redirect");
                rd.Values.Add("id", id);
                rd.Values.Add("page", page);
                rd.Values.Add("name", name);
                rd.Values.Add("controllerToRedirect", "Article");
                rd.Values.Add("actionToRedirect", "View");

                return rd;
            }
        }

        return null;
    }


    public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
    {
        return null;
    }
}

QueryStringUrlController.cs:

public class QueryStringUrlController : Controller
{
    public RedirectToRouteResult Redirect(long id, int page, string name,
        string controllerToRedirect, string actionToRedirect)
    {
        return RedirectToActionPermanent(actionToRedirect, controllerToRedirect, new { id = id, page = page, name = name });
    }
}

Assuming you have such routing as in my global.asax file (listed above) you can create a custom Route class that will handle incoming requests and map them on a special redirection controller which will then redirect them to appropriate urls with 301 state. Then you must add this route to global.asax before your "Article" routes

Answer 3

如果您使用的是IIS 7，则URL重写模块应适用于您的方案。