Introduction to ASP .NET MVC
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Transcript Introduction to ASP .NET MVC
ASP.NET MVC
INTRODUCTION TO ASP.NET MVC AND
EXAMPLE WALKTHROUGH
RAJAT ARYA (RAJATA@U)
EFECS - OIM
DAWG – 4/21/2009
Agenda
2
Definition
what is ASP.NET MVC?
Functional Description
how does ASP.NET MVC actually work?
Goal / Benefits
why is it important?
ASP.NET MVC Implementation Walkthrough
lets see this thing actually working
Questions?
Reference Materials
4/21/2009 - Rajat Arya (rajata@u) - DAWG
ASP.NET MVC Definition
3
The ASP.NET MVC framework provides an alternative to
the ASP.NET Web Forms pattern for creating MVCbased Web applications.
The ASP.NET MVC framework is a lightweight, highly
testable presentation framework that is integrated with
existing ASP.NET features, such as master pages and
membership-based authentication.
The MVC framework is defined in the System.Web.Mvc
namespace and is a fundamental, supported part of the
System.Web namespace.
(taken from http://www.asp.net/learn/mvc/tutorial-01-cs.aspx)
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Functional Description (is a)
4
Set of classes, containing:
Base class for Controllers
Base class for Views (extend ASP.NET View class)
Base class for Responses (ActionResult)
Default classes for Routing (wiring URLs to Controllers)
Plugin for Visual Studio
Adds project template
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Functional Description (how it works)
5
Registers itself with ASP.NET in Default.aspx.cs as an
HttpHandler and then handles all HTTP requests
public partial class _Default : Page
{
public void Page_Load(object sender, System.EventArgs e)
{
HttpContext.Current.RewritePath(Request.ApplicationPath,
false);
IHttpHandler httpHandler = new MvcHttpHandler();
httpHandler.ProcessRequest(HttpContext.Current);
}
}
Enables Routing System through web.config changes
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Functional Description (the parts)
6
Views
Display the application's user interface (UI).
Typically, this UI is created from the model data
Ex. an edit view of a Products table that displays text boxes, drop-down lists, and
check boxes based on the current state of a Products object.
Controllers
Handle user interaction, work with the model, and ultimately select a view to
render that displays UI.
Handles and responds to user input and interaction
Ex. handles query-string values, and passes these values to the model, which in
turn queries the database by using the values.
Routing
Define rules to route URLs to specific Controllers.
Providing inputs to specific Actions defined by the Controller.
Ex. http://www.example.com/products/info/1 could be routed to ActionResult
ProductsController.Information(int id) method
(parts taken from http://www.asp.net/learn/mvc/tutorial-01-cs.aspx)
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Functional Description (Views)
7
A view is a standard (X)HTML document that can
contain scripts.
Can be defined as an .aspx page, but no codebehind
Example: \Views\Home\Index.aspx
<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Index</title>
</head>
<body>
<div> The current date and time is <% Response.Write(DateTime.Now);%> </div>
</body>
</html>
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Functional Description (Controllers)
8
Class that extends System.Web.Mvc.Controller class
Defines public methods that return ActionResult for Actions the
controller handles
Each ActionResult method accepts inputs, does the processing
(works with Model / Repository / Business Logic Layer) and returns
ActionResult to user
A View is returned as a ViewResult from the Controller
Example: ProductsController
public class ProductsController : Controller
{
// GET: /Products/
public ActionResult Index()
{
// Add action logic here
return View();
}
}
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Functional Description (Routing)
9
Responsible for mapping browser requests to a particular
MVC Controller action.
Enabled in web.config file
Route table created in Global.asax file, called in
Application_Start() method
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute(
"Default",
// Unique route name
"{controller}/{action}/{id}",
// URL with parameters
new { controller = "Home", action = "Index", id = "" } // defaults
);
routes.MapRoute(
"ProductInfo",
"Products/Info/{id}",
new { controller = "Products", action = "Info", id = "" } // defaults
);
}
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Functional Description (Passing Data)
10
ViewData object is used to pass data between
Controllers and Views
ViewData is a dictionary object, which has a Model
property on it of type object
Use dictionary to pass data back, or use model object to set a
model that the View is to display
Controller does the following:
return View(“ViewName”, model);
ViewData[“id”] = 23;
return View();
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Functional Definition (request to response)
11
1.
2.
3.
4.
5.
6.
URL request for /products/info/1
Default.aspx.cs invokes MvcHttpHandler to handle request
MvcHttpHandler refers to Routing Rules registered in
Global.asax.cs (in Application_Start) to find a
Controller/Action that matches request
(/products/info/{id})
MvcHttpHandler instantiates controller and invokes
corresponding action method (using built in object mapper
to map parameters on URL as inputs to action method)
Calls ProductsController.Info(id=1) code
Info method works with Business Logic objects to perform
operation, sets any ViewData and returns a View as an
ActionResult
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Goals / Benefits (1)
12
Separation of Concerns
Separation of application tasks (input logic, business logic, and UI logic)
Does not use view state or server-based forms.
Testability
All core contracts in the MVC framework are interface-based and can be tested by using mock objects, which are
simulated objects that imitate the behavior of actual objects in the application
You can unit-test the application without having to run the controllers in an ASP.NET process, which makes unit
testing fast and flexible. You can use any unit-testing framework that is compatible with the .NET Framework.
Extensibility
All core contracts in the MVC framework are interface-based
Supports the use of Dependency Injection (DI) and Inversion of Control (IOC) container models.
Plug in your own view engine, URL routing policy, action-method parameter serialization, and other components.
Compatibility
ASP.NET MVC lets you use features such as forms authentication and Windows authentication, URL authorization,
membership and roles, output and data caching, session and profile state management, health monitoring, the
configuration system, and the provider architecture.
You can use existing ASP.NET features with the ASP.NET MVC framework, such as nested master pages, in-line
expressions (<%= %>), declarative server controls, templates, data-binding, localization, and so on.
4/21/2009 - Rajat Arya (rajata@u) - DAWG
(parts taken from http://www.asp.net/learn/mvc/tutorial-01-cs.aspx)
Goals / Benefits (2)
13
Powerful URL Mapping Component
Uses a Front Controller pattern that processes Web application requests through a
single controller. This enables you to design an application that supports a rich
routing infrastructure. For more information, see Front Controller on the MSDN Web
site.
URLs do not have to include file-name extensions, and are designed to support URL
naming patterns that work well for search engine optimization (SEO) and
representational state transfer (REST) addressing.
Well Documented and Lots of Active Development
Fully Supported by Microsoft
Open-Source under MS-PL license
Free!
4/21/2009 - Rajat Arya (rajata@u) - DAWG
(parts taken from http://www.asp.net/learn/mvc/tutorial-01-cs.aspx)
ASP.NET MVC Implementation Walkthrough
14
Small sample ASP.NET MVC application.
Taken from asp.net/mvc website
(http://static.asp.net/asp.net/images/mvc/32/CS/Co
ntactManager_7_CS.zip)
4/21/2009 - Rajat Arya (rajata@u) - DAWG
Fin.
QUESTIONS?
Reference Materials
16
http://www.asp.net/learn/mvc/ - really well done –
go here first!
http://weblogs.asp.net/scottgu/archive/tags/MVC/
ASP.NET/default.aspx - Scott Guthrie’s posts,
goodness, code,
http://www.hanselman.com/blog/CategoryView.asp
x?category=ASP.NET+MVC – Scott Hanselman’s
posts, good, less code
Unity/IoC
Running on IIS6 (or here)
4/21/2009 - Rajat Arya (rajata@u) - DAWG