[Latest update here] 

The attached sample implements simplified Web application paradigm (called “Plan 9 MVC”) based on ASP.NET MVC. It is page-centric (it hides Controllers) but it retains many of the benefits of ASP.NET MVC. The package contains a Visual Studio solution with two projects (the standard ASP.NET MVC starter template rewritten as a Plan 9 Web Site, and the library implementing Plan 9 framework), the license document, and README document.

ASP.NET MVC provides many benefits including:

  1. Separation of Concerns and the resulting testability
  2. Better control over HTML in MVC views (compared to classic Web Forms). Rendering using HTML helpers provided for MVC View Pages.
  3. Nice looking logical URLs
  4. Productivity features like binding of HTML form fields to action method arguments and declarative authorization rules (by decorating action methods)

Plan 9 completely ignores #1 above, as it does not have Controllers visible to the user. However, the other benefits stay.

The website does not have “Controllers” and “Views” folders – it has “Pages” folder instead, containing ASP.NET pages implemented as MVC View Pages, with HTML helpers. Requests are mapped to these pages using a simple rule: ~/Home/Index is routed to ~/Pages/Home/Index.aspx

The code normally found in Action Methods of a Controller, in Plan 9 applications resides in page methods, Page_Load and the newly introduced (in Plan 9) Page_Post.

Page_Load can be decorated with [Authorize] attribute, similar to how the attribute is used on Action Methods in Controllers:

    [Authorize]
    public void Page_Load() {
        ViewData["Title"] = "Change Password";
    }
    …

Page_Post method is only executed on HTTP POST requests and its arguments are automatically bound to the request data just as Action Method arguments are:

    public void Page_Load() {
        ViewData["Title"] = "Login";
    }
    
    public void Page_Post(string username, string password, bool rememberMe, string returnUrl) {
        …
    }

Plan 9 also introduces several helper methods for link generation and validation, to simplify the page code.

Internally Plan 9 implementation is based on ASP.NET MVC. The requests are routed to one controller (all to one Action Method) that dispatches them to the corresponding pages:

    public class Plan9Controller : Controller {
        public ActionResult Action() {
            string virtualPath = Plan9.GetPath(ControllerContext.RouteData);

            if (!HostingEnvironment.VirtualPathProvider.FileExists(virtualPath)) {
                throw new HttpException(404, string.Empty);
            }

            Plan9.CurrentControllerContext = ControllerContext;
            return View(new WebFormView(virtualPath));
        }
    }

Obviously, Plan 9 is not a true MVC framework and should not be considered as such. But it does provide a simple alternative way to develop web applications preserving many of the benefits of ASP.NET MVC. In the future it would be interesting to explore a hybrid model, applications that combine true MVC with Plan 9 sub-sections.

The name "Plan 9" refers to Plan 9 from Outer Space (a 1950s zero-budget Sci-Fi movie, some claim it to be the worst movie ever made -- it's so bad it's fun to watch).