ASP.NET MVC in Action Austin Code Camp, 2009

1. ASP.NET MVC in ActionAustin Code Camp, 2009 • Jeffrey Palermo • Chief Technology Officer • Headspring Systems

2. Agenda ASP.NET MVC History Getting Started The Model Controllers/Actions Views Routes AJAX MvcContrib Questions

3. ASP.NET MVC History • Oct 2007 – Scott Guthrie provides first glimpse at Alt.Net Conf in Austin, TX • Dec 2007 – First official CTP released • Dec 2007 – MvcContrib open source project launches • 2008 – 4 more CTPs released • Mar 2009 – First version released • Mar 2009 – MvcContrib 1.0 released • Today – Lots of buzz

4. Getting Started - Pattern

5. Getting Started - Components • .Net 3.5 SP1 • System.Web.Abstractions.dll • HttpContextBase • HttpRequestBase • etc • System.Web.Routing.dll • ASP.NET MVC v1.0 • System.Web.Mvc.dll • Extras • MvcContrib.dll • Microsoft.Web.Mvc.dll

6. Getting Started - Responsibilities • Controllers • Responsible for WHAT a screen does. • Views • Responsible for DISPLAYING the screen. • Models • Responsible for REPRESENTING the task.

7. Getting Started - Advantages • Decouples rendering logic from handling user input • Decouples screen logic from processing the http request • Leverages interfaces to separate responsibilities within the presentation layer • Provides complete control over markup rendered • Provides complete control over urls • Different presentation concerns can be independently tested

8. Getting Started - Web Forms? ASP.NET • HttpApplication • HttpContext • HttpRequest • HttpResponse • HttpRuntime • HttpUtility • IHttpHandler • IHttpModule WebForms • Server Lifecycle • Postback • ViewState ASPX • MasterPages • Themes, Skins • General Templating

9. Getting Started - ASP.NET MVC? ASP.NET • HttpApplication • HttpContext • HttpRequest • HttpResponse • HttpRuntime • HttpUtility • IHttpHandler • IHttpModule Mvc • Routes • Controllers • ViewData • Filters • MvcContrib ASPX • MasterPages • Themes, Skins • General Templating

10. Getting Started – New Project

11. Getting Started – Project Structure

12. Getting Started - Routes • Old • http://codecampserver.com?group=adnug&meeting=april09 • ASP.NET MVC • http://codecampserver.com/adnug/april09 { key1}/{ key2 } • Default: {controller}/{action}/{id}http://foo.com/product/edit/22063748ProductController.cspublic ViewResult Edit(string id){…}

13. Flow of an ASP.NET MVC Request • Request comes in to /Home • IIS determines the request should be handled by ASP.NET • ASP.NET gives all HttpModules a chance to modify the request • The UrlRoutingModule determines that the URL matches a route configured in the application

14. Flow of an ASP.NET MVC Request • The UrlRoutingModule gets the appropriate IHttpHandler from the IRouteHandler that is used in the matching route (most of the time, MvcRouteHandler)as the handler for the request • The MvcRouteHandler constructs and returns MvcHandler. • The MvcHandler, which implements IHttpHandler executes ProcessRequest.

15. Flow of an ASP.NET MVC Request • The MvcHandler uses IControllerFactory to obtain an instance of IController using the "controller" route data from the route {controller}/{action}/{id}. • The HomeController is found, and its Execute method is invoked. • The HomeController invokes the Index action.

16. Flow of an ASP.NET MVC Request • The Index action adds some objects to the ViewData dictionary. • The HomeController invokes the ActionResult returned from the action, which renders a view. • The “index” view in the views folder displays the objects in ViewData. • The view, derived from System.Web.Mvc.ViewPage, executes its ProcessRequest method. • ASP.NET renders the response to the browser.

17. The Model

18. Model - Long-lived architecture • What causes legacy code? • Dependencies • Coupling • Lack of validated feedback (testing)

19. Model - Layered Architecture UI Business Logic Data Access/Infrastructure

20. Model - Layered Architecture UI Business Logic Data Access WCF I/O

21. Model - Solution Structure Client Business Logic Web Service File Infrastructure Data Access DB

22. Model - Onion Architecture SpeakerController IConferenceRepository IUserSession User Interface Domain Services UserSession <<class>> Domain Services Objects (aggregates) Web Service Application Core/Domain Model Tests File Infrastructure ConferenceRepository <<class>> DB

23. Model - Solution Structure UI Core IoC Container Web Service File Infrastructure DB

24. Model - Onion Architecture (flattened) UI I/O WCF Data Access Domain Services Aggregates (entities)

25. Model - Data-Driven Architecture User Interface More Business Logic Business Logic Infrastructure DB Web Service File Tests Application Core

26. Controllers

27. Controllers – Icontroller

28. Controllers – Action

29. Controllers – Action Requirements • The method must be public. • The method cannot be a static method. • The method cannot be an extension method. • The method cannot be a constructor, getter, or setter. • The method cannot have open generic types. • The method is not a method of the controller base class. • The method cannot contain ref or out parameters.

30. Controllers – Action return types

31. Controllers – ActionResult

32. Controllers – Parameter Binding

33. Controllers – Parameter Binding public ActionResult Save(string conferenceKey, string firstName, string lastName, string email, string webpage) { //method body omitted. }

34. Controllers – Parameter Binding • Precedence • Form values • Route arguments • Querystring parameters

35. Controllers – Parameter Binding public class AttendeeForm { public virtual GuidConferenceID { get; set; } public virtual string FirstName { get; set; } public virtual string LastName { get; set; } public virtual string EmailAddress { get; set; } public virtual string Webpage { get; set; } } //resulting action method signature public ActionResult Save(AttendeeForm form){}

36. Controllers – ModelBinding

37. Controllers – Model Binding /conference/edit?conference=austincodecamppublic ActionResult Edit(Conference conference){…}

38. Controllers – Registering Binders

39. Controllers – ViewData

40. Controllers – Filters

41. Controllers – Action Filters • IActionFilter – before and after hooks when an action is executing • IResultFilter – before and after hooks when an action result is executing • IAuthorizationFilter – hooks when the controller is authorizing the current user • IExceptionFilter - hooks when an exception occurs during the execution of a controller

42. Controllers – Provided ActionFilters • System.Web.Mvc.ActionFilterAttribute • System.Web.Mvc.OutputCacheAttribute • System.Web.Mvc.HandleErrorAttribute • System.Web.Mvc.AuthorizeAttribute • System.Web.Mvc.ValidateAntiForgeryTokenAttribute • System.Web.Mvc.ValidateInputAttribute

43. Controllers – Applying Filters

44. Controllers – Action Selectors • System.Web.Mvc.AcceptVerbsAttribute – limits action selection to requests of the specified verb type • System.Web.Mvc.NonActionAttribute – prevents action method from being selected

45. Views

46. Views – Folder Structure

47. Views – IViewEngine

48. Views – View not found

49. Views – IView

50. Views – WebFormViewEngine • Uses <%=…%> code nuggets • No code-behind • Leverages Master Pages • Partial views can be .aspx or .ascx • Responsibility is rendering markup