ASP.NETHandlers & Modules

Session Time: 30-45minutes

By: Sunil Pottumuttu

Agenda

• Introduction• The Problem• Extension Based Preprocessor• Event Based Preprocessor• Overall Picture • Steps to Implement• The Final Output

IIS & ASP.NETRequest Workflow

Application

HTTPResponse

asp.dll

aspnet_isapi.dll

*.asp

*.asmx

HTTPRequest

Process Request

Web.configMachine.config

IISIIS

ASP.NET Configuration

• Machine.config defines default handlers or handler factories to manage requests

• Web.config may alter Machine.config settings at the application level

Machine.config Overrides Web.config

<httpHandlers> <add verb=“GET" path="*.xml" type=“DotNetDashboard.Web.FileDownloadHandler, DotNetDashboard.Web, Version=1.0.0.0, Culture=neutral, PublicKeyToken=xxx"/> <add verb="*" path=“displayImage.aspx" type=“DotNetDashboard.Web.ImageFormatter, DotNetDashboard.Web, Version=1.0.0.0, Culture=neutral, PublicKeyToken=xxx” /> <add verb="*" path=“*.xls” type="System.Web.HttpForbiddenHandler"/></httpHandlers>

<httpHandlers> <add verb="*" path="*.aspx" type="System.Web.UI.PageHandlerFactory"/> <add verb="*" path="*.asmx" type="System.Web.Services.Protocols.WebServiceHandlerFactory, System.Web.Services, …/><add verb="*" path="*.soap" type="System.Runtime.Remoting.Channels.Http.HttpRemotingHandlerFactory,

System.Runtime.Remoting, …/> <add verb="*" path="*.config" type="System.Web.HttpForbiddenHandler"/></httpHandlers>

HttpHandler - The Extension Based Preprocessor

HttpModule - Event Based Preprocessor

Hook to the Events

Overall Picture

Some Handlers

IIS 7 – Handler Mappings & Demo

IIS 7 – Http Modules & Demo

Synchronous vs Asnchronous• synchronous request, the

ProcessRequest method is executed, and any markup produced is sent to the browser once the entire request is processed• BeginProcessRequest and the

EndProcessRequest

Virtual File Provider

• Global.asax provides hooks into the events of the ASP.NET pipeline just like an httpModule

• Global.asax provides is the capability to add handlers to events not available to modules, like Session_Start and Session_End.

• httpModules have over Global. asax is the ability to compile modules into class libraries that can be used in multiple ASP.NET web sites

Modules vs Global.asax

• synchronous request, the ProcessRequest method is executed, and any markup produced is sent to the browser once the entire request is processed• BeginProcessRequest and the

EndProcessRequest

Imp Http Modules Events

• BeginRequest • AuthenticateRequest • AuthorizeRequest • EndRequest • Error

Demo Material

Demo Material