Introduction to ASP.NET MVC Blogging Engine in 60 minutes

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Introduction to ASP.NET MVC Blogging Engine in 60
minutes

• Adnan Masood
• www.AdnanMasood.com
• www.CodePlex.com/YABE

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About Meaka. 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 adnanmasood_at_acm.org
• 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

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YABEYet another blogging engine

• Team
• Adnan Masood
• Jeff Bergman
• Sean Xiao
• www.CodePlex.com/YABE
• Uses Linq to SQL for data access
• Syndication Libraries for the RSS/Atom Feeds
• Experiment in learning MVC

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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.

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MVC vs. Classic ASP.NET
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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.

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Model View Controller Pattern
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More Concrete Model View Controller Pattern
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Why use ASP.NET MVC?

• 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/10-10-
  2007/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, lt gt 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.

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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

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The answer to Urls 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.

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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 11 correspondence between a URL and a
  resource.

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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

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Why MVC?

• Very Clean separation of Concerns
• Unit Testing
• Model that leads you down a maintainable path
  (prevent crappy code)
• Clean Urls and Html

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Front Controller

• Classic asp.net framework is Page Controller
• Map Urls to classes/controllers instead of Pages

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Unit Testing

• Mock Objects to simulate responses.
• Dont have to go through a page or view
• Red/Green Testing

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Unit Testing

• Create instance of controller
• controller.ViewEngine new TestViewEngine()
• Uses Mock Objects

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Features

• Routing
• Controller
• View
• Dependency Injection
• Pluggable
• Interfaces for all core contracts

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Url

• 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

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Route Examples

• ltControllergt/ltActiongt/ltParamgt
• http//domain/Home/CustomerDetail/45
• Html.Link for creating outbound urls
• Html.Link(ltFriendly Namegt, ltActiongt, ltControllergt)

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Controller

• IController
• Execute(IHttpContext ctx, RouteData routeData)
• class MyController Controller
• ControllerAction attribute

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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

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Views

• View probably shouldnt directly access data
  sources or services.
• Use the ViewData which stores the model the view
  is rendering
• ViewPageltTgt, ViewPage

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Future of the ASP.NET MVC

• MVC for the Enterprise
• Classic Asp.Net for quicker implementations

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References

• Download the Latest MVC Preview
  3http//www.microsoft.com/downloads/details.aspx?
  FamilyId92F2A8F0-9243-4697-8F9A-FCF6BC9F66ABdisp
  laylangen
• ASP.NET MVC Preview 3http//www.hanselman.com/blo
  g/ASPNETMVCPreview3.aspx
• Quick Start Guideshttp//quickstarts.asp.net/3-5-
  extensions/mvc/default.aspx
• Upcoming Changes in Routinghttp//haacked.com/arc
  hive/2008/04/10/upcoming-changes-in-routing.aspx
• Scott Guthries Post on ASP.NET MVC
  Frameworkhttp//weblogs.asp.net/scottgu/archive/2
  007/10/14/asp-net-mvc-framework.aspx

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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
  adnanmasood_at_gmail.com
• Visit www.CodePlex.com/YABE
• Visit www.AdnanMasood.com