Transcript ASP.NET MVC Blogging Engine

Introduction to ASP.NET MVC
Blogging Engine in 60 minutes
Adnan Masood
www.AdnanMasood.com
www.CodePlex.com/YABE
About Me
aka. Shameless Self Promotion
• Sr. Software Engineer / Tech Lead for Green Dot Corp. (Financial
Institution)
• Design and Develop Connected Systems
• Involved with SoCal Dev community, co-founded San Gabriel Valley .NET
Developers Group. Published author and speaker.
• MS. Computer Science, MCPD (Enterprise Developer), MCT, MCSD.NET
• Doctoral Student - Areas of Interest: Machine learning, Bayesian Inference,
Data Mining, Collaborative Filtering, Recommender Systems.
• Contact at [email protected]
• Read my Blog at www.AdnanMasood.com
• Doing a session in IASA 2008 in San Francisco on Aspect Oriented
Programming; for details visit http://www.iasaconnections.com
YABE
Yet another blogging engine
• Team
– Adnan Masood
– Jeff Bergman
– Sean Xiao
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www.CodePlex.com/YABE
Uses Linq to SQL for data access
Syndication Libraries for the RSS/Atom Feeds
Experiment in learning MVC
Latest Developments in the MVC world
• Scott Guthrie, adaptation from RoR
• How does this relate to Visual Studio 2008/.NET 3.5 SP1 Beta?
• It doesn't. For now ASP.NET MVC is an out-of-band Web
downloadable thing. It's bin deployable (meaning you don't HAVE
to put them in the GAC) and you don't even need to tell your
hosting/ISP. They are what they are - three DLLs in a folder. Bam.
• MVC Preview 3 will not be affected by having SP1 installed. Preview
3 will include newer privately versioned bin deployable builds of the
Routing and Abstractions DLLs. That way these assemblies will not
be affected by the versions in the GAC installed by SP1, because they
will have different version numbers.
MVC vs. “Classic” ASP.NET
Ok, so what is this MVC thingy?
• It is an ASP.NET framework that performs data exchange by
using a REST model versus the postback model of classic
ASP.NET. Each page is split into two distinct components controller and view - that operate over the same model of
data. This is opposed to the classic code-behind model
where no barrier is set that forces you to think in terms of
separation of concerns and controllers and views. However,
by keeping the code-behind class as thin as possible, and
designing the business layer appropriately, a good
developer could achieve separation of concerns even
without adopting MVC and its overhead. MVC, however, is
a model superior to a properly-done code-behind for its
inherent support for test-driven development.
Model View Controller Pattern
More Concrete Model View Controller
Pattern
Why use ASP.NET MVC?
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It enables clean separation of concerns, testability, and TDD by default. All core contracts within the MVC
framework are interface based and easily mockable (it includes interface based
IHttpRequest/IHttpResponse intrinsics). You can unit test the application without having to run the
Controllers within an ASP.NET process (making unit testing fast). You can use any unit testing framework
you want to-do this testing (including NUnit, MBUnit, MS Test, etc).
It is highly extensible and pluggable. Everything in the MVC framework is designed so that it can be easily
replaced/customized (for example: you can optionally plug-in your own view engine, routing policy,
parameter serialization, etc). It also supports using existing dependency injection and IOC container
models (Windsor, Spring.Net, NHibernate, etc).
It includes a very powerful URL mapping component that enables you to build applications with clean
URLs. URLs do not need to have extensions within them, and are designed to easily support SEO and
REST-friendly naming patterns. For example, I could easily map the /products/edit/4 URL to the "Edit"
action of the ProductsController class in my project above, or map the /Blogs/scottgu/10-102007/SomeTopic/ URL to a "DisplayPost" action of a BlogEngineController class.
The MVC framework supports using the existing ASP.NET .ASPX, .ASCX, and .Master markup files as "view
templates" (meaning you can easily use existing ASP.NET features like nested master pages, <%= %>
snippets, declarative server controls, templates, data-binding, localization, etc). It does not, however, use
the existing post-back model for interactions back to the server. Instead, you'll route all end-user
interactions to a Controller class instead - which helps ensure clean separation of concerns and testability
(it also means no viewstate or page lifecycle with MVC based views).
The ASP.NET MVC framework fully supports existing ASP.NET features like forms/windows authentication,
URL authorization, membership/roles, output and data caching, session/profile state management, health
monitoring, configuration system, the provider architecture, etc.
Why MVC is so different?
• REST is an architectural pattern that defines how
network resources should be defined and addressed in
order to gain shorter response times, clear separation
of concerns between the front-end and back-end of a
networked system. REST is based on three following
principles:
• An application expresses its state and implements its
functionality by acting on logical resources
• Each resource is addressed using a specific URL syntax
• All addressable resources feature a contracted set of
operations
The answer to Url’s Life, 42.
• In the MVC Framework, a URL is seen as the
mean to address a logical server resource, but
not necessarily an ASPX file to parse. So the URLs
employed by the pages of an MVC Framework
application have a custom format that the
application itself mandates. In the end, the MVC
Framework employs a centralized HTTP handler
that recognizes an application-specific syntax for
links. In addition, each addressable resource
exposes a well-known set of operations and a
uniform interface for executing operations.
What? No more postbacks!
• The MVC Framework doesn't support classic
postbacks and viewstate and doesn't consider
any URL as the endpoint to a physical server
file to parse and compile to a class. In ASP.NET,
you have a 1:1 correspondence between a
URL and a resource.
Why MVC? (links)
• The REST-like Aspect of MVC Framework
• ASP.NET MVC Framework: An early look
• RSS Feed with the new ASP.NET MVC
Framework
• MVC, REST, and the Alternative ASP.NET
Framework
• ASP.NET MVC framework - ready or not
Why MVC?
• Very Clean separation of Concerns
• Unit Testing
• Model that leads you down a maintainable
path (prevent crappy code)
• Clean Urls and Html
Front Controller
• Classic asp.net framework is Page Controller
• Map Urls to classes/controllers instead of
Pages
Unit Testing
• Mock Objects to simulate responses.
• Don’t have to go through a page or view
• Red/Green Testing
Unit Testing
• Create instance of controller
• controller.ViewEngine = new TestViewEngine();
• Uses Mock Objects
Features
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Routing
Controller
View
Dependency Injection
Pluggable
Interfaces for all core contracts
Url
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Url no longer points to the view/aspx page
A Url maps to a controller class
Allows more flexibility to map Urls
Url routing engine, Route table
Routes are tokenized strings
Can use RegEx
Route Examples
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<Controller>/<Action>/<Param>
http://domain/Home/CustomerDetail/45
Html.Link for creating outbound urls
Html.Link(<Friendly Name>, <Action>,
<Controller>)
Controller
• IController
• Execute(IHttpContext ctx, RouteData
routeData)
• class MyController : Controller
• [ControllerAction] attribute
View
• Similar to existing page
• No postback or view state
• Not all page events will fire
• Editing forms will be more work
• Separate page for viewing, editing, and updating
• Ajax will use UserControls as update panels but
request still goes through the control
Views
• View probably shouldn’t directly access data
sources or services.
• Use the ViewData which stores the model the
view is rendering
• ViewPage<T>, ViewPage
Future of the ASP.NET MVC
• MVC for the Enterprise
• Classic Asp.Net for quicker implementations
References
• Download the Latest MVC Preview 3
http://www.microsoft.com/downloads/details.aspx?FamilyId=92F2
A8F0-9243-4697-8F9A-FCF6BC9F66AB&displaylang=en
• ASP.NET MVC Preview 3
http://www.hanselman.com/blog/ASPNETMVCPreview3.aspx
• Quick Start Guides
http://quickstarts.asp.net/3-5-extensions/mvc/default.aspx
• Upcoming Changes in Routing
http://haacked.com/archive/2008/04/10/upcoming-changes-inrouting.aspx
• Scott Guthrie’s Post on ASP.NET MVC Framework
http://weblogs.asp.net/scottgu/archive/2007/10/14/asp-net-mvcframework.aspx
Questions?
• ASP.NET MVC is a new paradigm for .NET Developers; a new way
to think about programming web application.
• Any Questions / Comments … feel free to contact
[email protected]
• Visit www.CodePlex.com/YABE
• Visit www.AdnanMasood.com