MVC +Areas + Routes... Order of Routes Matter!

The order in which routes are registered, really is pretty damn important, otherwise it can have really strange side-effects.

I have a site, which has 3 areas, and no default... 'non-area'.

• Admin
• Members
• Site

So rather than having the structure:

Where the root/default site is in the main directory, with two areas. I wanted this structure:

So no root/default, and just a 'Site' area which would be the default.

Note:The default route is removed from Global.asax... for now

This works perfectly fine if all the URL's are accessed like:

http://localhost:147/Site/Home/Index

http://localhost:147/Admin/Home/Index

http://localhost:147/Member/Home/Index

If we run this in a browser we get the following:

These routes are registered automatically when you add an Area, in a AreaNameAreaRegistration file.

The routes generated look like the following:

namespace RoutingIssue.Areas.Members
{
    public class MembersAreaRegistration : AreaRegistration
    {
        public override string AreaName
        {
            get
            {
                return "Members";
            }
        }
        public override void RegisterArea(AreaRegistrationContext context)
        {
            context.MapRoute(
                "Members_default",
                "Members/{controller}/{action}/{id}",
                new { action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}

But with different AreaName's of course. You get the idea.

Now what we want to do is change the Site route, to work from the root directly like:

http://localhost:147/

This is where my assumptions began to go wrong... I updated the route like so:

public override void RegisterArea(AreaRegistrationContext context)
{
    context.MapRoute(
        "Site_default",
        "{controller}/{action}/{id}",
        new { controller = "Home", action = "Index", id = UrlParameter.Optional }
    );
}

So I've removed 'Site' from the path, and added the default controller.

This is where things started to get messy. At first, it worked, in my sample project. Then I added AutoFac, MiniProfiler, some Content, and a few other things. That's when it all went pear shaped.

It seems to have lost the information about the routes for Admin/Member.

Creating a new project with it working, and with my current project. I wrote some Trace.Write("AreaName") code into each AreaRegistration. The working project outputted:

• Members
• Admin
• Site

However the second project, where it was failing, outputted:

• Site
• Members
• Admin

So what's happening is in my project, it registers the default route first without the Area:

context.MapRoute(
    "Site_default",
    "{controller}/{action}/{id}",
    new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);

Took me hours to figure this out. That MVC cannot guarantee the order of which Area's are registered. The second two Area's didn't stand a chance.

The solution was to move the Site route to the global.asax file, and specify an Area on it. My Site registration looks like:

public override void RegisterArea(AreaRegistrationContext context)
{
    //context.MapRoute(
    //    "Site_default",
    //    "{controller}/{action}/{id}",
    //    new { controller = "Home", action = "Index", id = UrlParameter.Optional }
    //);
    Trace.WriteLine("Site");
}

While my global.asax file has:

public static void RegisterRoutes(RouteCollection routes)
{
    routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
    routes.MapRoute(
        "default",
        "{controller}/{action}/{id}",
        new { controller = "Home", action = "Index", id = UrlParameter.Optional },
        new string[] { "RoutingIssue.Areas.Site.Controllers" }
    ).DataTokens.Add("Area", "Site");
}

This means the default route is registered after my Areas, and everything works perfectly again :)

comments powered by Disqus