17 April 2008 ASP.NET MVC, Codeplex, MVC Robert Muehsig

Microsoft released a new version of the MVC Framework.

Update: Scott Guthrie wrote a blogpost about the “Release” - this “Release” is not the MVC Preview 3, it´s more a “Preview” of the “Preview 3” ;)

The new version introduce more ActionFilter methodes and other refactorings. Here is the overview from the Codeplex ReadMe:

MVC Changes Since Preview 2

  • Action methods on Controllers now by default return an ActionResult instance, instead of void.
    • This ActionResult object indicates the result from an action (a view to render, a URL to redirect to, another action/route to execute, etc).
    • Each "result" is a type that inherits from ActionResult. To render a view, return a RenderViewResult instance.
  • The RenderView(), RedirectToAction(), and Redirect() helper methods on the Controller base class now return typed ActionResult objects (which you can further manipulate or return back from action methods).
  • The RenderView() helper method can now be called without having to explicitly pass in the name of the view template you want to render.
    • When you omit the template name the RenderView() method will by default use the name of the action method to determine the view template to render.
    • So calling RenderView() with no parameters inside the About() action method is now the same as explicitly writing RenderView('About').
  • Introduced a new IActionFilter interface for action filters. ActionFilterAttribute implements IActionFilter.
  • Action Filters now have four methods they can implement representing four possible interception points.
    • OnActionExecuting which occurs just before the action method is called.
    • OnActionExecuted which occurs after the action method is called, but before the result is executed (aka before the view is rendered in common scenarios).
    • OnResultExecuting which occurs just before the result is executed (aka before the view is rendered in common scenarios).
    • OnResultExecuted which occurs after the result is executed (aka after the view is rendered in common scenarios).
    • NOTE: The OnResult* methods will not be called if an exception is not handled during the invoking of the OnAction* methods or the action method itself.
  • Added a MapRoute extension method (extension on RouteCollection) for use in declaring MVC routes in a simpler fashion.

NOTE: It is pretty easy to update existing Controller classes built with Preview 2 to use this new pattern (just change void to ActionResult and add a return statement in front of any RenderView or RedirectToAction helper method calls). Routing changes since Preview 2

  • URLs may contain any literal (except for /) as a separator between URL parameters. For example, instead of {action}.{format} you can now have {action}-{format}. For more details on changes, see this post.
  • Routing is ignored for files that exist on disk by default. This can be overriden by setting the RouteTable.Routes.RouteExistingFiles property to true (it is false by default).

I will try out the new bits in the next days and maybe write some new blogposts :)

Written by Robert Muehsig

Software Developer - from Saxony, Germany - working on primedocs.io. Microsoft MVP & Web Geek.
Other Projects: KnowYourStack.com | ExpensiveMeeting | EinKofferVollerReisen.de