HTTP Host header as route value

Question

I am trying to serve multiple virtual hosts from the same code base. One thought I had was pass the HTTP Host header as a route value because I did't want to rely on HttpContext in the controllers because of unit testability.

I had planned on exposing this route value in a controller base class or something like that. I tried passing as a route value like this:

routes.MapRoute(
  "Default", // Route name
  "{controller}/{action}/{id}", // URL with parameters
  new { host = HttpContext.Current.Request.Url.Host, controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);

This yields an HttpException: Request is not available in this context.

Any ideas or suggestions on a better way to do this would be appreciated.

Answer 1

You should be fine relying on the Context when testing your controller. The routing system has been designed with testability in mind so you could set a mock context that provides the right URL when your tests run.

The reason why your code does not work is because you are probabling invoking it from the global Application_Start event which happens before the first request comes in. This means that an HttpContext object is not available at that time.