ASP.NET MVCÖNSEL AKIN

Controllers & Actions

Controllers

Responsible for controlling the flow of application

Exposes public methods as actions Each action returns different results

types Inherits from

System.Web.Mvc.Controller

Returning Action Results ViewResult View() PartialViewResult PartialView() RedirectResult Redirect() ContentResult Content() JsonResult Json() FileResult File() EmptyResult HttpUnauthorizedResult JavaScriptResult JavaScript() RedirectToRouteResult RedirectToRoute()

Returning View Results

Returns HTML to the browser Implicit vs Explicit view naming

return View();return View(‘’ViewName’’)

Specifying pathsreturn View(‘’SubFolder/ViewName’’)return View(‘’~/View.aspx’’)

Returning Redirect Results Same controller

return RedirectToAction(‘’Index’’); Different controller

return RedirectToAction(‘’Product’’, ‘’List’’);

Providing route valuesreturn RedirectToAction(‘’Product’’,

‘’Details’, new { id = 20 });

Returning Content Results return Content(‘’Hello’’); Returning .Net types

public string HelloAction() {return ‘’Hello’’;

} ToString() and wrapping with

ContentResult

Returning Json Results Returns result in JavaScript Object

Notation (JSON) format Uses JavaScriptSerializer

{ id: 10, name: ‘SharePoint 2010’, authors: [{ ‘onsela’, ‘mehmeta’ }]

}

var books = new List<Book>();return Json(books);

Returning JavaScriptpublic ActionResult ShowMessage() {

return JavaScript(‘’alert(‘Message!’);’’);}

// View.aspx<%: Ajax.ActionLink(‘’Show message’’, ‘’ShowMessage’’, null) %>

Accessing Request InformationRequest.QueryString RouteData.Route

Request.Form RouteData.Values

Request.Cookies HttpContext.Application

Request.HttpMethod HttpContext.Cache

Request.Headers HttpContext.Session

Request.Url HttpContext.Items

Request.UserHostAddress User

TempData

Action Method Parameters – 1

public ActionResult ShowInfo(string city) {// Equivalent tovar tempCity = Request.Form[‘’city’’];

} Optional Parameters

Nullable typesDefaultValueAttributeOptional Parameters with C# 4.0

Complex Parameterspublic ActionResult Update(Product p) { .... }

Action Method Parameters – 2

Invoking model binding manuallypublic ActionResult Update(int productID) {

var product = repository.Get(productID);

UpdateModel(product);repository.Update(product);return View(product);

}

Passing Data to Views – 1

Controllers and views are totally independent

Controllers suply data to views No way to access controllers from

views Supplying data from a controller

ViewData[‘’product’’] = productObject; Accessing data from the view

<%: ((Product)ViewData[‘’product’’]).Name %>

Passing Data to Views – 2

Sending strongly typed objects to viewspublic ActionResult ProductInfo(int id) {

var product = repository.Get(id);return View(product);

}

// View.aspxProduct Name: <%: Model.Name %>

Passing Data to Views – 3 Passing dynamic objects to viewspublic ActionResult ProductDetails(int id) {

dynamic model = new ExpandoObject();model.Product = repository.Get(id);model.Message = ‘’Out of Stock’;return View(model);

}// View.aspx<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<dynamic>" %>

Product: <%: Model.Product.Name %>Message: <%: Model.Message %>

Using TempData

Similar usage with ViewData Preserves data across redirections

public ActionResult Update(Product product) {repository.Update(product);TempData[‘’message’’] = ‘’Product ‘’ + product.Name + ‘’

updated.’’;return RedirectToAction(‘’Success’’);

}

// Success action view.aspx<% if (TempData[‘’message’’] != null) %>

<p><%: TempData[‘’message’’] %></p><% } %>

Using Filters

Injects extra behaviors to controller and actions

Derive from FilterAttribute class Basic types of filters

IAuthorizationFilter AuthorizeAttribute

IActionFilter ActionFilterAttribute

IResultFilter ActionFilterAttribute

IExceptionFilter HandleErrorAttribute

Applying Filters

[Authorize(Roles=‘’Administrator’’)]public class ProductController : Controller {

[OutputCache(Duration=30)]

public ActionResult Save(Product p) {

}

}

How Filters are Executedtry{

Run each IAuthorizationFilter's OnAuthorization() methodif(none of the IAuthorizationFilters cancelled execution){

Run each IActionFilter's OnActionExecuting() methodRun the action methodRun each IActionFilter's OnActionExecuted() method (in reverse order)Run each IResultFilter's OnResultExecuting() methodRun the action resultRun each IResultFilter's OnResultExecuted() method (in reverse order)

}else{

Run any action result set by the authorization filters}

}catch(exception not handled by any action or result filter){

Run each IExceptionFilter's OnException() methodRun any action result set by the exception filters

}

IActionFilter, IResultFilter Methods

OnActionExecuting() Before the action runs Prevent executionInspect & edit parameters

OnActionExecuted() After the action runs Edit the exceptionChange the result

OnresultExecuting() Before the ActionResult is executed

Inspect ActionResultPrevent execution

OnResultExecuted() After the ActionResult is executed

Obtain exception detailsInspect ActionResult

Authorize Filter

Run early in the request Users property Roles property Order property

[Authorize(Roles=‘’SalesRep’’, Users=‘’onsela’’)]public ActionResult ProductList() {

return View();}

HandleError Filter

Detects exceptions Renders a specific view Returns HTTP status code 500 to

clients[HandleError(View=‘’ErrorPage’’, ExceptionType=typeof(SqlException)]public ActionResult ProductList() {

return View();}

OutputCache FilterDuration

VaryByParam

VaryByHeader

VaryByCustom

VaryByContentEncoding

Location Server / Client / DownStreamServerAndClient = Server & ClientAny = Server & DownStreamNone

NoStore

CacheProfile

SqlDependency

Order Irrelevant

Handling Unknown Actionspublic class HomeController : Controller{

protected override void HandleUnknownAction(string actionName)

{.....

}}