mvc presentation
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What’s wrong with WebForms?• Web Forms allow developers to rapidly create applications simply by dragging and dropping
controls and handling page-level events for both the page and the controls on the page. This works well, but it’s a high-level of abstraction and many developers completely forget—or never learned—how the HTML layout actually works behind the scenes. As a result, it’s common to end up with non-validating HTML, or bloated and hard-to-manage HTML layout that is very designer unfriendly. Add to that a huge amount of ViewState if you don’t effectively manage ViewState properly and you can easily end up with pages that are much bigger than they need to be and slow as molasses.
• One downside of the Web Forms framework is that behind this abstraction layer, Microsoft built a very complex engine that has many side effects in the Page pipeline. If you’ve ever built complex pages that contain many components on the page it can sometimes get very difficult to coordinate the event sequence for data binding, rendering, and setup of the various controls at the correct time in the page cycle. Do you load data in the Init, Load or PreRender events or do you assign values during postback events? Web Forms need to run through a single server-side form so they can’t easily be broken up into smaller logical units. In complex forms, event handlers can get very bulky with the tasks they need to handle and often in ways that can’t be easily refactored so you end up with code that is difficult to maintain and impossible to test.
– Rick Strahl – MVP since 1997
Webforms?
Who uses MVC?
• StackOverflow.com– Serves 1.4-1.5 million hits per day. (as of May, 2010)– A language-independent collaboratively edited question and answer
site for programmers. Questions and answers displayed by user votes and tags.
– Alexa traffic ranked 465, 451 in the US, and 212 in India
• It's no coincidence that many of the most popular web programming frameworks also encapsulate MVC principles: Django, Ruby on Rails, CakePHP, Struts, and so forth. It's also officially creeping into ASP.NET under the fledgling ASP.NET MVC project. – Jeff Atwood of CodingHorror.com May,2008
MVC vs webforms• ASP.net MVC
– Enables the full control over the rendered HTML.– Provides clean separation of concerns(SoC).– Enables Test Driven Development (TDD).– Easy integration with JavaScript frameworks.– Following the design of stateless nature of the web.– RESTful urls that enables SEO.– No ViewState and PostBack events
• Lightweight/faster
– No Codebehind• ASP.net Web Forms
– It provides RAD development– Easy development model for developers coming from winform development.
MVC + webforms
• You can intermix the two• Use MVC for routing, separation, more
javascript/jQuery friendliness• Use webforms for complex controls that you
are attached to or are just better for the situation.
• Both use some T4 style-coding
What is M.V.C?
• Model – The classes which are used to store and manipulate state, typically in a database of some kind.
• View – Your application’s presentation code or layer
• Controller – Wires up your model to your View/presentation/public interface (winforms, web pages, web services, soap, rest, etc..)
How does it work?
Web forms flow vs. MVC flow
Asp.net MVC with routingUser does a Get or Post to the routing system. The routing system tries to find a route match, and creates an instance of the appropriate controller.Then it invokes the Action on the controller.
The controller invokes methods on the model, which passes back any relevant data used in response.
The controller then usually locates the view and renders the view using the data from the model (in many cases transformed or flattened in a ViewModel or in the controller) .
Sample Layout
• Controllers– Define your externally
visible methods/URLs
• Models– Your Core code +
persistence
• Views– Pages to render
• Global.asax (not pictured)– Defines routes, and other
app-startup code
References
• What’s Ailing Asp.Net Web Forms – Rick Strahl• http://www.codinghorror.com/blog/2008/05/
understanding-model-view-controller.html• http://www.aspiringcraftsman.com/2007/08/i
nteractive-application-architecture/