MVC3 Routing strange behavior

Question

I found something strange with routing...

I´m testing a MVC3 application in Visual Studio Web Express 2012

• I created a new MVC3 application to isolate the problem

• I added the following route before the default route:

      routes.MapRoute(
          "default_localization",
          "{language}/{country}/{controller}/{action}/{id}",
          new { controller = "Home", action = "Index", id = UrlParameter.Optional }
      );
  

• Then without any other change (there are no areas anything just the initial files after creating the project), I ran the application and at first sight everything was working fine. Since it is a new application there are two links at the top of the page:

  • Home
  • About

The action links look like:

<li>@Html.ActionLink("Home", "Index", "Home")</li>
<li>@Html.ActionLink("About", "About", "Home")</li>

Then this is what is happening:

• When the browser URL is: http://localhost:54870/

  • The Home link is: http://localhost:54870/
  • The About link is: http://localhost:54870/Home/About

  HTML

  <li><a href="/">Home</a></li>
  <li><a href="/Home/About">About</a></li>
  

  Which is OK

• But after clicking the About link, the browser URL is: http://localhost:54870/Home/About

  • The Home link becomes: http://localhost:54870/Home/About
  • The about link becomes: http://localhost:54870/Home/About/Home/About

  They still execute the correct action even when the link is messed up.

  HTML

  <li><a href="/Home/About">Home</a></li>
  <li><a href="/Home/About/Home/About">About</a></li>
  

If I remove my custom routing everything works as expected

• Why is this happening?

• How can I fix it?

Answer 1

I just found the problem

Basically I read several routing articles and finally I got it, my problem was that my custom route was been picked up always after I clicked the About link

Why?

Let's consider it:

When my URL was http://localhost:54870/, my custom route was not picked up because I didn't have default values for {language} and {country} therefore my route didn't match

But when my URL was http://localhost:54870/Home/About my custom route was always picked up because the route engine assumed that Home/About were the {language} and {country} segments and since I had default values for {controller} and {action} the rout simply was a match

Well I learnt my lesson and I learnt more about routing. In the future I'm planning to follow the KISS principle when defining routes

Answer 2

Try replacing your route with something like this:

routes.MapRoute(
    "default_localization",
    "{language}/{country}/{controller}/{action}/{id}",
    new { language = "en", country = "US", controller = "Home", action = "Index", id = UrlParameter.Optional }
);

See if that works.

Hope this is of help to you.