An Introduction to ASP.NET MVC 1.0

							Keyvan Nayyeri




                 http://nayyeri.net
   Classic ASP
   The .NET Framework
   ASP.NET 1.0
   ASP.NET 1.1
   ASP.NET 2.0
   ASP.NET AJAX
   ASP.NET 3.5
   ASP.NET 4.0
 Desktop-like development with controls and
  events
 Classic model of development with wizards
  and controls
 Ease of state management
 Ease of tooling
 The lack of best practices for development
 The lack of control over project elements
 The lack of control over rendered HTML code
 The lack of separation of concerns (and
  testability)
 Many repetitions of code in a project
 Heavy pages to accomplish state
  management (ViewState)
 Lower level of flexibility and customizability
 Resolving the weaknesses with ASP.NET
  WebForms
 Responding to new requirements of today’s
  Software/Web Development
 Having the market share regarding the
  success of Ruby on Rails and other
  technologies
 ASP.NET WebForms as the new and correct
  name for original ASP.NET technology
 ASP.NET Dynamic Data for Data-Driven web
  development
 ASP.NET MVC for web development with
  MVC pattern
 Splitting the implementation of an application
  into three components
 Providing a high level of separation of
  concerns that improves the testability and
  maintainability
 Suitable for applications that deal with data
  storage and user interactions
 Model
  Business Logic
  Data Interaction
 View
  User Interaction
 Controller
  The bridge between the model and the view
 Implements the MVC pattern for ASP.NET
 Replaces the fundamental classes in ASP.NET
  with appropriate implementation
 Applies the core ASP.NET API with relevant
  implementation for ASP.NET MVC
  development
 Provides a high level of control,
  customizability, flexibility, and extensibility
 High level of separation of concerns
 A default project structure
 Naming convention over configuration
 Open to change and expansion
 Ready to integrate with third party
  components and libraries
 Basic but powerful core to be used by
  developers
 WebForms applications are faster to develop
 MVC applications are easier to maintain
 MVC applications have higher quality
 MVC applications are easier to test
 MVC applications are easier to expand and
  customize
 MVC applications take more effort for state
  management
 MVC applications have user interfaces that
  are compliant to web-standards
 WebForms is neither dead nor classic
 Testability is a benefit of good separation of
  concerns and ASP.NET MVC is not about unit
  testing
 WebForms is still a great technology with
  some advantages over MVC
 MVC is not supposed to be as classic as
  WebForms and there shouldn’t be much
  tooling around it
 No event-based model anymore
 Request filtering based on HTTP verbs in
  Action Methods replaces the event model in
  ASP.NET WebForms
 A combination of user interface elements and
  programming code to load and display data in
  views
 Similar to classic ASP but no business logic is
  embedded in views
 Usage of interfaces and abstract base classes
  for abstraction is strongly recommended
 Controllers in Controllers folder
 Model and data interaction files
  in Models folder
 Views, Master Pages, and User
  Controls in Views folder
 JavaScript files and jQuery
  library in Scripts folder
 By default ASP.NET MVC
  doesn’t work property without
  the correct structure of files and
  folders
 Model
 Controller
  Action Method
  Action Filter
 View
  HtmlHelper
 Routing
   Responsible for data interaction and business
    logic implementation
   The ambiguous part of ASP.NET MVC
   M is the only part of MVC that is not
    implemented in ASP.NET MVC
   There is only a Models folder in project
    template
   You can use your favorite technology: LINQ to
    SQL, Entity Framework, NHibernate, …
 Acts like a bridge between the model and the
  view
 It’s a wrong belief to put business logic in
  controller
 Settings can be applied to this component
 It can be considered as one of the simplest
  parts of an ASP.NET MVC application
 Located in Controllers folder
 A class derived from Controller base class
 The class name should consist of the
  controller name + “Controller”
 The main job is done by public methods inside
  the controller (Action Methods)
 Unit testing primarily deals with testing the
  controller and its Action Methods.
A simple controller class
using System.Web.Mvc;

namespace SampleMvcApplication.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            ViewData["Message"] = "Welcome to ASP.NET MVC!";

            return View();
        }

        public ActionResult About()
        {
            return View();
        }
    }
}
 A public method in a controller
 Gets arbitrary number of parameters from
  URL or request
 Proceeds with the request and passes the
  appropriate data items from the model to the
  view or vice versa
 Returns an instance of ActionResult or other
  derivations for specific purposes
 There are various derivations of ActionResult
  in the framework or you can write your own
   An attribute that can be applied to the action
    methods
   Used to apply the settings or customize the
    behavior
   There are many Action Filters in the
    framework
   You can write your own Action Filters
   Some common examples of Action Filters are
    for Authorization, Caching, and HTTP verb
    filtering
A simple Action Filter

[Authorize]
public ActionResult ChangePassword()
{
    ViewData["PasswordLength"] = MembershipService.MinPasswordLength;

    return View();
}
 Responsible for user interaction
 Views have similar responsibilities as pages in
  ASP.NET WebForms
 Master pages and user controls have the same
  responsibilities as ASP.NET WebForms
 Designers and developers should build user
  interfaces with basic HTML elements with
  creativity
 Basic HTML elements are provided via
  HtmlHelpers
A simple View

<%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="indexTitle" ContentPlaceHolderID="TitleContent" runat="server">
    Home Page
</asp:Content>
<asp:Content ID="indexContent" ContentPlaceHolderID="MainContent" runat="server">
    <h2>
        <%= Html.Encode(ViewData["Message"]) %></h2>
    <p>
        To learn more about ASP.NET MVC visit <a href="http://asp.net/mvc" title="ASP.NET MVC Website">
            http://asp.net/mvc</a>.
    </p>
</asp:Content>
 A set of helper methods attached to the Html
  property of the ViewPage
 Provide basic user interface elements such as
  TextBox or Button
 One of the good extensibility points to
  develop your own helper method
 There are already some community
  extensions such as HtmlHelper for Gravatar or
  ReCaptcha
   Enables RESTful access to resources in
    ASP.NET
   Not a specific part of MVC or ASP.NET MVC
   Responsible to map requests based on their
    pattern to appropriate controller and action
    methods
   Can be modified and expanded in several
    ways
   Ends with better URLs for ASP.NET
    applications
A simple routing definition
using System.Web.Mvc;
using System.Web.Routing;

namespace SampleMvcApplication
{
    public class MvcApplication : System.Web.HttpApplication
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                "Default",                                               // Route name
                "{controller}/{action}/{id}",                            // URL with parameters
                new { controller = "Home", action = "Index", id = "" }   // Parameter defaults
            );
        }

        protected void Application_Start()
        {
            RegisterRoutes(RouteTable.Routes);
        }
    }
}
   ASP.NET MVC uses the same API as ASP.NET
    WebForms with minor changes in usage
   Configurative approach is still in place but
    declarative usage with Action Filters is
    preferred
   Membership and Role providers can be used
   The default project template has a rich
    implementation that can be used easily
   Form authentication can be implemented
    with the same principles as ASP.NET
    WebForms
   AJAX is very different from ASP.NET
    WebForms
   Basic but key tools are provided as AjaxHelper
    methods: ActionLink and BeginForm
   Complex AJAX scenarios can be built based on
    these tools
   Third party libraries can be used easily
   jQuery is distributed as a part of ASP.NET
    MVC project template with Visual Studio
    Intellisense
 MVC development is tied to some of the
  modern development approaches
 Dependency Injection can be achieved with
  abstraction in your code
 Dependency Injection helps ameliorating
  Test-Driven Development and maintenance
 Unit Testing helps finding the possible holes in
  your code
 Mainly consists of comparing the ViewData
  items in an Action Method with your
  expectations
 You have to follow abstraction in your code to
  make testing easier
 You can use mock frameworks to speed up
  the unit testing process
 Other part of the application (i.e. routing) can
  be tested as well
 ASP.NET MVC is very extensible
 Almost everything in ASP.NET MVC can be
  replaced or expanded
 Some community projects focus on
  alternative implementations for ASP.NET
  MVC components such as ViewEngine or
  Controller Factory
 MvcContrib is a notable project available at
  http://www.codeplex.com/MVCContrib
 Many times migration is not necessary
 Migration can consist of easy and difficult
  steps
 The process varies significantly by original
  implementation and features that are used
 Migration can be done smoothly with the
  possibility to run ASP.NET WebForms and
  ASP.NET MVC in the same project side-by-
  side
 You may need to find alternatives for some
  parts such as server controls
Getting Started with ASP.NET MVC 1.0
DZone Refcard
By Simone Chiaretta and Keyvan Nayyeri

 A compact and quick starter guide to ASP.NET
  MVC 1.0
 Will be available as free PDF and printed card
  with high quality
 Check out http://refcardz.dzone.com for
  updates
Beginning ASP.NET MVC 1.0
By Simone Chiaretta and Keyvan Nayyeri
Published by Wrox (August 2009)

 Dedicated to all Iranians
  around the world
 Covers all basic concepts
  and principles
 Discusses all the major
  topics about ASP.NET MVC
  with a pragmatic approach