Training slides for Microsoft customers

1. ASP.NET MVC 2.0
10/29/2010

2. Buu Nguyen
• Microsoft MVP, MCSD.NET, SCJD, SCBCD
• Vice President of Technology, KMS Technology
• Lecturer, RMIT University Vietnam

3. Table of Contents
Core
• ASP.NET MVC Basics
• Routing
• Controllers & Action Methods
• View Results & Views
Advanced
• Action Method Selectors
• Filters
• Model Validation
• Model Templates
• And beyond…

4. ASP.NET MVC BASICS

5. Overview of ASP.NET MVC
• MVC-based .NET web development platform
• Alternative, not replacement, for Web Forms
• Built openly & iteratively
(http://www.codeplex.com/aspnet)
• Releases
• Latest RTM release is ASP.NET MVC 2.0
• Latest release is ASP.NET 3.0 Beta

6. Technology Stack
ASP.NET Web
Forms
ASP.NET MVC
ASP.NET Framework
(Configuration, Security, Membership, Roles, Profiles, Routing, Caching,
Session, Application State, Cookie, .aspx/.ascx/.asax/.master files etc.
.NET Framework

7. ASP.NET MVC Pros & Cons
Advantages
• Clear separation of
concerns
• Testability & TDD
• Tight-control over markup
• Extensibility
• Search-engine
friendliness
• Good parts of ASP.NET
Disadvantages
• No out-of-the-box rich UI
helper methods
• Learning curve is (a bit)
stiffer than Web Forms
• Community is not yet as
crowded as Web Forms

9. Project Structure
• Project Conventions
• Content: CSS, images etc.
• Controllers: controller classes
• Models: model classes
• Views
• [Controller]: controller-specific views
• Shared: master pages, user controls, shared views etc.
• Scripts: JavaScript files

10. MvcHandler
Action
Result
Controller
Factory
Action
View
Engine
View
View
Result
Controller
forwards
invokes
produces produces
defines
Model
Route
maps

11. About TodoApp
• Allow users to manage tasks
• To spend our time wisely, we‟ll:
• Utilize the Membership API for user management
• Use Entity Framework for DB logic

12. Let’s see the completed TodoApp

13. ROUTING

14. Overview
• Enabled by UrlRoutingModule
• Introduced since ASP.NET 3.5 SP1
• Independent from ASP.NET MVC
• Responsibilities
• Map incoming URLs to route info
• Construct outgoing URLs from route info

15. Incoming URL to Route Info
actual value becomes
TaskController.cs

16. Route Constraints
• Strings (regular expression)
• Classes implementing IRouteConstraint
 E.g. HttpMethodConstraint
 Custom constraints

17. Outgoing URLs & Links
• Generate outgoing URL from route info
• UrlHelper#Action(…)
• Generate outgoing link from route info
• HtmlHelper#ActionLink(…)

18. MvcHandler
Action
Result
Controller
Factory
Action
View
Engine
View
View
Result
Controller
forwards
invokes
produces produces
defines
Model
Route
maps

19. CONTROLLERS & ACTION METHODS

20. Controllers
• Usually inherit from Controller class
• Can directly inherit from IController interface
• Usually correspond to an entity or domain concept
• Instantiated by a controller factory
• Can create a custom controller factory (e.g. to apply dependency
injection)

21. Action Methods
• Public methods of a controller
• Each action method corresponds to 1 HTTP request &
response
• Input sources for action methods
• Context objects
• Parameters
• Output of action methods is an object implementing
ActionResult interface

22. Input #1 – Common Context Objects
• Request.QueryString
• Request.Form
• Request.Cookie
• Request.Headers
• HttpContext.Application
• HttpContext.Session
• HttpContext.Items
• HttpContext.Cache
• RouteData.Values
• User
• Authentication info of the current user
• TempData
• Data stored in the previous request in the same session
• etc.

23. Input #2 – Action Method Parameters
• Action methods have their parameters supplied
from the following sources
• Request.QueryString
• Request.Form
• RouteData.Values
• Complex-typed parameters can be supplied too
• This is called model binding
• It‟s possible to implement custom model binders

24. Action Method Results
• Action methods return objects implementing
ActionResult
• Each subclass overrides ExecuteResult() method to work with
the Response object
• Send file, redirect, render HTML etc.
• It‟s possible to implement custom action result

25. Built-in Action Result Types
Action Result Type Examples of Use (in action methods)
ViewResult return View();
return View(“view”, modelObject);
PartialViewResult return PartialView();
return PartialView(“partialview”, modelObject);
RedirectToRouteResult return RedirectToRoute(“LogOn”);
RedirectResult return Redirect(“http://www.microsoft.com”);
ContentResult return Content(rss, “application/rss+xml”);
FileResult return File(“chart.ppt”, “application/ppt”);
JsonResult return Json(someObject);
JavaScriptResult return JavaScript("$(„#table‟).init();");
HttpUnauthorizedResult return new HttpUnauthorizedResult();
EmptyResult return new EmptyResult();
ActionResult Base class for all action results, including custom ones

26. MvcHandler
Action
Result
Controller
Factory
Action
View
Engine
View
View
Result
Controller
forwards
invokes
produces produces
defines
Model
Route
maps

27. VIEW RESULTS & VIEWS

28. ViewResult
• The call to View(…) generates a ViewResult object
• ViewResult lookups a view engine to render the content
• The default view engine is WebFormViewEngine
• ASP.NET MVC 3 is shipped with the Razor view engine
• Custom view engines for XSLT, Brail, NHaml, etc. are available
• View path lookup
• Either View("~/path/to/some/view.aspx");
• Or if controller (& action) are specified
• /Views/ControllerName/ViewName.aspx
• /Views/ControllerName/ViewName.ascx
• /Views/Shared/ViewName.aspx
• /Views/Shared/ViewName.ascx

29. ViewData
• Controllers pass data to view via the ViewData dictionary
• Directly, e.g. ViewData[“key”] = obj;
• View model object, e.g. ViewData.Model = obj

30. ViewData Dictionary

31. Model Object

32. The Familiar Web Forms View
• You can reuse most of your ASP.NET Web Form
knowledge, for examples:
• Directives & syntax
• Localization
• Master page
• (MVC) user control
• Things you shouldn‟t use:
• Server control (unless reusing)
• Code-behind & Web Forms life-cycle
• Things you couldn‟t use:
• View state
• Post back

33. Dynamic Code Options
Technique Description
Inline code The same old <% … %> and <%= … %>
HTML Helpers Built-in or extension methods for HtmlHelper class,
e.g. Html.TextBox(…), Html.BeginForm(…) etc.
Partial views Render MVC user controls, which can be reused in
many places, e.g. Html.RenderPartial(“Task”)
Partial action Invoke an MVC action and execute returned action
result, e.g. Html.RenderAction("ShowTagCloud",
"BlogEntry")
Server controls Using standard ASPX control registration & using
syntax

34. Common HtmlHelper Methods
• For each of the above, there‟s a corresponding
Html.XxxFor(…) method that works with expression tree
Method Corresponding HTML
Html.CheckBox(…) <input id=“…" name=“…" type="checkbox" value=“…"
…/>
Html.TextBox(…) <input id=“…" name=“…" type="text" value=“…" …/>
Html.TextArea(…) <textarea id=“…" name=“…" …>…</textarea>
Html.Password(…) <input id=“…" name=“…" type=“…" value=“…" …/>
Html.RadioButton(…) <input checked=“…" id=“…" name=“…"
type=“…" value=“…" …/>
Html.Hidden(…) <input id=“…" name=“…" type=“…" value=“…" …/>
Html.BeginForm(...) <form id=“…” …>…</form>

35. Custom HtmlHelper Methods

36. MvcHandler
Action
Result
Controller
Factory
Action
View
Engine
View
View
Result
Controller
forwards
invokes
produces produces
defines
Model
Route
maps

37. ACTION METHOD SELECTORS

38. Action Method Selectors
• Attributes used in Controller#Execute() to know
which action to invoke
• Built-in selectors
• AcceptVerbs(HttpVerbs)
• Or more convenient versions: HttpGet & HttpPost
• Inherit ActionMethodSelectorAttribute
• Override bool IsValidForRequest(…)

39. FILTERS

40. Filters
• .NET attributes adding logic
• Before & after action method invocation
• Before & after action result invocation
• During unhandled exception
• During request authorization
• Filters can be applied to
• Individual action
• All actions in a controller
• Built-in filters: OutputCacheAttribute, AuthorizeAttribute, ValidateInputAttribute,
ValidateAntiForgeryTokenAttribute, HandleErrorAttribute, ChildActionOnly

41. Types of Filter
Filter Type Interface Methods to Override
Authorization filter IAuthorizationFilter OnAuthorization()
Action filter IActionFilter OnActionExecuting(),
OnActionExecuted()
Result filter IResultFilter OnResultExecuting(),
OnResultExecuted()
Exception filter IExceptionFilter OnException()

42. MODEL VALIDATION

43. Business Rule Validation
• Business rules needs enforcing
• User name must be supplied
• Email format must be correct
• It‟s also desirable to enforce rules at both server-
side and client-side
• DRY principle must be followed for maintainability

44. ASP.NET MVC Model Validation
• Apply one or more validation attributes to the
model classes and/or their properties
• The model binding process validates and
populates ModelState.Errors collection
• Check result with ModelState.IsValid or
ModelState.IsValidField(propertyName)
• More error can be added after model binding
• ModelState.AddModelError(key, message);
• key: use string.Empty for non-property error

45. DataAnnotations Validation Attributes
Attribute Description
Range Validates whether the property value falls in a min-max
range
RegularExpression Validates the property against a specified regular expression
Required Validates whether the property value is provided
StringLength Validates the maximum length of a property value
Validation The base class for all validation attributes, including custom
attributes

46. Model Validation in Views
• Html Helper Methods
• Html.ValidationSummary(
bool excludePropertyErrors, string message)
• Html. ValidationMessage(
string modelName)
• Html. ValidationMessageFor(
Expression<Func<TModel, TProperty>> expression)
• Html.EnableClientValidation()
• References to JavaScript files
• ~/scripts/jquery-1.3.2.min.js
• ~/scripts/jquery.validate.min.js
• ~/scripts/MicrosoftMvcJQueryValidation.js

47. MODEL TEMPLATES

48. Model Templates
• Developers describe rendering rules using
metadata
• ASP.NET MVC renders based on metadata using
built-in or custom templates

49. DataAnnotations UI Attributes
Attribute Description
DisplayName Used in Html.Label()/LabelFor() to generate the label text
HiddenInput Generates a hidden input for the property
DataType Indicates the data type of the property (e.g. Email, Password)
ScaffoldColumn Indicates whether the property should be shown or ignored
DisplayFormat Adds formatting rules to the property (e.g. DataFormatString,
NullDisplayText etc.)
ReadOnly Indicates that users shouldn‟t be able to modify the property
UIHint Specifies a template to use

50. Model Templates in Views
• Display
• Html.Display(“PropertyName”)
• Html.DisplayFor(model => model.PropertyName)
• Html.DisplayForModel()
• Editor
• Html.Editor(“PropertyName”)
• Html.EditorFor(model => model.PropertyName)
• Html.EditorForModel()

51. AND BEYOND…

52. And Beyond…
ASP.NET MVC 2
• Areas
• Asynchronous controller
ASP.NET MVC 3 Beta
• Razor view engine
• NuPack
• Global filters
• JSON model binding
• Better DI support
• …

53. THANK YOU!
buunguyen@kms-technology.com
http://vn.linkedin.com/in/buunguyen
www.twitter.com/buunguyen