DEV402

Extending the ASP.NET Runtime

Jurgen PostelmansMicrosoft Regional Director BeLuxU2U

Agenda

Role of the HttpRuntime

What is the HttpRuntimeThe HttpContext class

Extending the HttpRuntimeHttpModules

Global.asax

HttpHandlers

Hosting the HttpRuntime

Using HttpModules Using HttpModules and HttpHandlersand HttpHandlers

demodemo

Role of the Http Runtime

Pluggable, modular architectureCaching, Security, State Management….

Ability to customize and extend ASP.NETExample: Perform dynamic authorizationExample: Take over .xml file extension

Reduce need for C/C++ ISAPIsGoal: You can do everything in ASP.NETUse any managed language, including VB .NET

HTTPHTTPRequest Request HandlerHandler

ASP.NET ArchitectureInside IIS 5.0

INETINFO.EXEINETINFO.EXE(IIS 5.0)(IIS 5.0)

aspnet_isapi.dllaspnet_isapi.dll

ASPNET_WP.EXEASPNET_WP.EXEWorker ProcessWorker Process

Named pipes

http://www.foo.com/bar.aspxhttp://www.foo.com/bar.aspx

ASP.NET ArchitectureInside IIS 5.0

HTTP.SYSHTTP.SYSHTTP.SYSHTTP.SYS

User Mode

Kernel Mode

ASP.NETASP.NET

FiltersFilters

Worker Worker ProcessProcess

ASP.NETASP.NET

FiltersFilters

Worker Worker ProcessProcess

ASP.NETASP.NET

FiltersFilters

Worker Worker ProcessProcess

WASWASWASWAS

INETINFOINETINFO

metabasemetabase

AppPool 1AppPool 1 AppPool 2AppPool 2

Http Runtime Architecture

HttpHandlers

HttpModulesHtt

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.asmx.asmx .aspx.aspx .ashx.ashx

OutputCacheOutputCache

AuthenticationAuthentication

SessionState SessionState

Process BoundaryProcess Boundary

Cache

External Session

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HttpContextEverything you needed to know about the current ASP.NET Request but where afraid to ask

About HttpContext

The glue that ties the pipeline togetherEncapsulates all request specific data

Instance created for each requestSystem.Web.HttpContext

“flows” throughout request lifetime

Developers can add to HttpContextHttpContext.Items collection

Objects then flowed throughout request

Exposed via static HttpContext.CurrentCode must be running on original thread

HttpContext Properties

Name Type DescriptionCurrent HttpContext Context for the current request

Application HttpApplicationState Appliction-wide property bag

ApplicationInstance HttpApplication Application Context (Modules)

Session HttpSessionState Per-client session state

Request HttpRequest The HTTP Request

Response HttpResponse The HTTP Response

User IPrincipal Principal information

Handler IHttpHandler HTTP Handler that will dispatch the call

Items IDictionary Per-request property bag

Server HttpServerUtility URL cracking/sub handlers

Error Exception First error occured during processing

Using HttpContextUsing HttpContext

demodemo

Implementing HttpModulesParticipate in every ASP.NET request

HttpModules

Enables developers to: Extend the HTTP Pipeline

Examine and modify HTTP Requests

Used by ASP.NET:External Session State HttpModule

Forms Authentication HttpModule

Output Cache HttpModule

….

HttpRuntime Architecture

HttpModulesHtt

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HttpHandlers

.aspx.aspx .asmx.asmx .ashx.ashx

OutputCacheOutputCacheOutputCacheOutputCache

AuthenticationAuthenticationAuthenticationAuthentication

SessionState SessionState SessionState SessionState

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OutputOutput CachedCached PagePage Cache

External Session

HttpModules What Are Interception Events?

Request participationMethods called at specific stages of request

HttpRequest HttpResponse available

Terminate processing of request HttpApplication.CompleteRequest()Response.End()

Per-Request Application Events

BeginRequestAuthenticateRequestAuthorizeRequestResolveRequestCacheAquireRequestStatePreRequestHandlerExecuteHandler ExecutionPostRequestHandlerExecuteReleaseRequestStateUpdateRequestCacheEndRequest

Creating an HttpModule

Class must implement interface:System.Web.IHttpModule

Init()Called when module is created

Register delegates for runtime events

Dispose()

public interface IHttpModule {public interface IHttpModule {

public void Init(HttpApplication application);public void Init(HttpApplication application);public void Dispose();public void Dispose();

}}

Registering an HttpModule

1. Compile into .NET assembly2. Deploy

Into application’s \bin directory orRegister in the GAC

3. Register in configuration:

<configuration> <configuration> <system.web> <system.web> <httpModules> <httpModules> <add name=“friendly name”<add name=“friendly name” type=“class, assembly“ />type=“class, assembly“ /> </httpModules> </httpModules> </system.web></system.web></configuration></configuration>

Modules vs Global.asax

Functionality of global.asax and modules overlap

Global.asax supports extra events likeApplication_Start and Application_End

Session_Start and Session_End

Writing Modules Writing Modules

demodemo

Implementing HttpHandlersTaking control of the request target

What are HttpHandlers ?

Are the endpoint for a requestThey actually process the request and generate the response (HTML, XML,…)

Similar to ISAPI Extensions

Examples:ASP.NET Page Handler (*.aspx)

ASP.NET Service Handler (*.asmx)

Server-Side XSL Transformer (*.xml)

Dynamic image generation

Creating an HttpHandler

Class must implement interface:System.Web.IHttpHandler

ProcessRequest()‘Main’ method of the handler

IsReusable { get; }Indicates whether pooling is supported

public interface IHttpHandler {public interface IHttpHandler {public void ProcessRequest(HttpContext context);public void ProcessRequest(HttpContext context);public bool IsReusable();public bool IsReusable();

}}

Registering an HttpHandler

1. Compile into .NET assembly2. Deploy

Into application’s \bin directory orRegister in the GAC

3. Register in configuration:

4. Important: Extension must be mapped in IIS

<configuration> <configuration> <system.web> <system.web> <httpHandlers> <httpHandlers>

<add verb="*" path="myfile.myext" <add verb="*" path="myfile.myext" type="class, assembly" /> type="class, assembly" /> </httpHandlers> </httpHandlers> </system.web> </system.web></configuration></configuration>

Writing HandlerWriting Handler

demodemo

Writing an Writing an Asynchronous HandlerAsynchronous Handler

demodemo

Hosting the HttpRuntime

ASP.NET Hosting

HttpRuntime is a clean abstractionEnable non-IIS hosting scenarios

System.Web.Hosting namespace

Scenarios:Pre-generation of .htm for dynamic pages

ASP.NET Cassini server (XP Home)See http://www.asp.net/Projects/Cassini/Download/Default.aspx?tabindex=0&tabid=1 for sample source

Hosting ASP.NETHosting ASP.NET

demodemo

Community Resources

Community Resourceshttp://www.microsoft.com/communities/default.mspx

Most Valuable Professional (MVP)http://www.mvp.support.microsoft.com/

NewsgroupsConverse online with Microsoft Newsgroups, including Worldwidehttp://www.microsoft.com/communities/newsgroups/default.mspx

User GroupsMeet and learn with your peershttp://www.microsoft.com/communities/usergroups/default.mspx

Suggested Reading And Resources

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© 2003 Microsoft Corporation. All rights reserved.© 2003 Microsoft Corporation. All rights reserved.This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.