Transcript Spring 2006 Connections Conference Template

AMS304: Introduction to the
ASP.NET Model View Controller
(MVC) Framework
Scott Hanselman
Microsoft
[email protected]
Eilon Lipton
Microsoft
[email protected]
MVC
INTRO
Goodness
• Maintain Clean Separation of Concerns
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Easy Testing
Red/Green TDD
Highly maintainable applications by default
• Extensible and Pluggable
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Support replacing any component of the
system
Goodness
• Enable clean URLs and HTML
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SEO and REST friendly URL structures
• Great integration within ASP.NET
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Support both static and dynamic languages
What’s the Point?
• This is not Web Forms 4.0
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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
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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.
MVC
Model
View
Controller
A Little More Detail
Model
View
•Browser requests /Products/
•Route is determined
•Controller is activated
•Method on Controller is invoke
•Controller does some stuff
•Renders View, passing in
custom ViewData
•URLs are rendered,
pointing to other
Controller
Controllers
Even More Detail – Request Flow
Request
• You can futz at each step
in the process
URL
Routing
Http
Handler
Controller
Response
Route
Route
Handler
View
Factory
View
Demo – Hello MVC World
Don’t fall asleep, it’ll be worth it.
MVC
HOW IT WORKS
Basic Controller Handling
• Scenarios, Goals and Design
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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);
}
}
Basic Views
• Scenarios, Goals and Design:
●
Are for rendering/output.
• Pre-defined and extensible rendering helpers
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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
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) });
}
Demo – Routing
The route less travelled…
MVC
HOW TO TEST IT
Interfaces and TDD
• Mockable Intrinsics
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IHttpContext, IHttpResponse, IHttpRequest
• Extensibility
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IController
IControllerFactory
IRouteHandler
IView
IViewFactory
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);
}
Controller Factory
• Scenarios, Goals and Design:
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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));
}
View Factory
• Scenarios, Goals and Design:
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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);
Demo – TDD
Wasn’t this demo technically
supposed to be first?
Demo – Dynamic Data
Controls
Not DDE. Scared you, didn’t I?
Demo – ImageGen
It’s your thing.
Do what you wanna do.
Demo – Ruby View Engine
& Python Controller
It’s a kinder, gentler Microsoft.
No seriously. Hug?
Demo – XML-RPC
SOAP is for dorks.
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.
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!