This document introduces the ASP.NET MVC framework. It discusses how MVC enables clean separation of concerns through distinct model, view, and controller components. Controllers handle requests and choose views to render while passing them model data. Views focus on rendering output. The document also outlines how MVC supports testable, RESTful code through interfaces and dependency injection. It provides examples of routing, controller actions, view selection, and testing approaches. Finally, it demonstrates MVC concepts through sample projects.

1. AMS304: Introduction to the
ASP.NET Model View Controller
(MVC) Framework
Scott Hanselman Eilon Lipton
Microsoft Microsoft
scottha@microsoft.com elipton@microsoft.com

2. MVC
INTRO

3. Goodness
• Maintain Clean Separation of Concerns
● Easy Testing
● Red/Green TDD
● Highly maintainable applications by default
• Extensible and Pluggable
● Support replacing any component of the
system

4. Goodness
• Enable clean URLs and HTML
● SEO and REST friendly URL structures
• Great integration within ASP.NET
● Support both static and dynamic languages

5. What’s the Point?
• This is not Web Forms 4.0
● It’s about alternatives. Car vs. Motorcycle.
• Simple or as complex as you like
● Extend it, add IOC. Or not. If the shoe pinches, don’t
wear it.
• Fundamental
● Part of System.Web and isn’t going anywhere.
• Plays Well With Others
● Feel free to use NHibernate for Models, Brail for
Views and Whatever for Controllers. Be Happy.

6. MVC
Model
View Controller

7. A Little More Detail
•Browser requests /Products/
•Route is determined
Model •Controller is activated
•Method on Controller is invoke
•Controller does some stuff
•Renders View, passing in
custom ViewData
•URLs are rendered,
pointing to other
View Controller Controllers

8. Even More Detail – Request Flow
Request • You can futz at each step
in the process
URL Http
Routing Controller Response
Handler
Route View
Route View
Handler Factory

9. Demo – Hello MVC World
Don’t fall asleep, it’ll be worth it.

10. MVC
HOW IT WORKS

11. Basic Controller Handling
• Scenarios, Goals and Design
● URLs route to controller “actions”, not pages –
mark actions in Controller.
● Controller executes logic, chooses view.
[ControllerAction]
public void ShowPost(int id) {
Post p = PostRepository.GetPostById(id);
if (p != null) {
RenderView("showpost", p);
} else {
RenderView("nosuchpost", id);
}
}

12. Basic Views
• Scenarios, Goals and Design:
● Are for rendering/output.
• Pre-defined and extensible rendering helpers
● Can use .ASPX, .ASCX, .MASTER, etc.
● Can replace with other view technologies:
• Template engines (NVelocity, Brail, …).
• Output formats (images, RSS, JSON, …).
• Mock out for testing.
● Controller sets data on the View
• Loosely typed or strongly typed data

13. URL Routing – Pretty URIs
• Developers adds Routes to a global RouteTable
• Mapping creates a RouteData - a bag of key/values
protected void Application_Start(object sender, EventArgs e)
{
RouteTable.Routes.Add(new Route {
Url = "Blog/bydate/[year]/[month]/[day]",
Defaults = new { controller="blog", action="showposts" },
Validation = new { year=@"d{1,4}", month= @"d{1,2}",
day = @"d{1,2}"} });
RouteTable.Routes.Add(new Route {
Url = "[controller]/[action]/[id]",
RouteHandler = typeof(MvcRouteHandler) });
}

14. Demo – Routing
The route less travelled…

15. MVC
HOW TO TEST IT

16. Interfaces and TDD
• Mockable Intrinsics
● IHttpContext, IHttpResponse, IHttpRequest
• Extensibility
● IController
● IControllerFactory
● IRouteHandler
● IView
● IViewFactory

17. Testing Controller Actions
• No requirement to mock out full ASP.NET runtime.
[TestMethod]
public void ShowPostsDisplayPostView() {
TestPostRepository repository = new TestPostRepository();
TestViewFactory viewFactory = new TestViewFactory();
BlogController controller = new BlogController(…);
controller.ShowPost(2);
Assert.AreEqual("showpost", viewFactory.LastRequestedView);
Assert.IsTrue(repository.GetPostByIdWasCalled);
Assert.AreEqual(2, repository.LastRequestedPostId);
}

18. Controller Factory
• Scenarios, Goals and Design:
● Hook creation of controller instance
• Dependency Injection.
• Object Interception.
public interface IControllerFactory {
IController CreateController(IHttpContext context,
RouteData routeData,
Type controllerType);
}
protected void Application_Start(object s, EventArgs e) {
ControllerBuilder.Current.SetDefaultControllerFactory(
typeof(MyControllerFactory));
}

19. View Factory
• Scenarios, Goals and Design:
● Mock out views for testing
● Replace ASPX with other technologies
public interface IViewFactory {
IView CreateView(IHttpContext context,
RouteData routeData,
string viewName, string layoutName,
object viewData);
}
Inside controller class:
ViewFactory = new XmlViewFactory(...);
RenderView("foo", myData);

20. Demo – TDD
Wasn’t this demo technically
supposed to be first?

21. Demo – Dynamic Data
Controls
Not DDE. Scared you, didn’t I?

22. Demo – ImageGen
It’s your thing.
Do what you wanna do.

23. Demo – Ruby View Engine
& Python Controller
It’s a kinder, gentler Microsoft.
No seriously. Hug?

24. Demo – XML-RPC
SOAP is for dorks.

25. Conclusion
• This is not Web Forms 4.0
● It’s about alternatives. Car vs. Motorcycle.
• Simple or as complex as you like
● Extend it, add IOC. Or not. If the shoe pinches, don’t
wear it.
• Fundamental
● Part of System.Web and isn’t going anywhere.
• Plays Well With Others
● Feel free to use NHibernate for Models, Brail for
Views and VB for Controllers. Be Happy.

26. Your Feedback is Important
Please fill out a session evaluation form and
either put them in the basket near the exit
or drop them off at the conference
registration desk.
Thank you!