This document discusses ASP.NET handlers and modules. HttpModules are classes that plug into the request processing pipeline and respond to application events. They can store global state between requests and implement cross-cutting functionality. HttpHandlers process incoming HTTP requests and are mapped to file extensions. Common handlers include ASP.NET pages, web services, and generic handlers. The document demonstrates how to create custom HttpModules and HttpHandlers, and discusses deployment options such as publishing to local IIS.

1. ASP.NET 4.0
Julie Iskander
MSC. Communication and Electronics

2. Lecture Outlines
 Handlers and Modules
 Deploying web application

3. HttpHandlers and
HttpModules

6. HttpModules
 Simple classes that can plug
themselves into the request-
processing pipeline
 Attaching to events thrown by the
application.
 Similar to Global.asax

7. Global.asax HttpModules
 Store global state  Store global state
between requests between requests
 Respond to application-  Respond to application-
wide events wide events
 A separate
 Specific application
assembly, that can be
referenced by any
application
 Implements generic
functionality that’s useful
between different
applications.
Global.asax vs. HttpModules

8. Creating an HTTPModule
 Create a class implementing
System.Web.IHttpModule interface
 Requires to implement : Init and
Dispose
◦ Init:
 Input parameter: HttpApplication context
 Access current application context
 To implement HttpModule functionality
 Used to wire-up different events that fire during
request processing

9. Creating an HTTPModule
◦ Dispose:
 called once when the application terminates.
 Application terminates and reinitializes when:
 The application or IIS restarts,
 The Web.config configuration file or a dependent
assembly is modified.
 Configure module in web.config

12. Convert from an HTML to an aspx page

14. ASP.NET features handled by
modules:
 Output Caching
 Session State
 Windows Authentication
 Forms Authentication
 Passport Authentication
 Role manager
 Anonymous Identification
 Profile
 ErrorHandlerModule

16. HttpHandlers
 The last stop for incoming HTTP
Request
 The point in the request processing
pipeline that is responsible for serving
up the requested content
 Mapped to a specific file extension
(.aspx, .html,.jpg…………)
 Unlike modules, only one handler is
used to process a request.

17. Built-in HTTP Handlers
Handler Description
ASP.NET page handler (*.aspx) The default HTTP handler for all
pages.
Web service handler (*.asmx) The default HTTP handler for Web
services
Generic Web handler (*.ashx) The default HTTP handler for all
Web handlers that do not have a
UI and include @WebHandler
directive

18. Creating HttpHandlers
 Using generic handler .ashx
 Mapping the HttpHandler to a custom
file extension.

19. Generic HttpHandlers
 Add new item Generic Handler
(*.ashx)
 Class implements IHttpHandler
◦ ProcessRequest:
 Actually process incoming HTTP request.
 Input argument:
 HTTPContext object has access to all objects of the
current HTTP context as
response, request, user, profile, ……..
◦ IsReusable:
 Property to let ASP.NET know whether incoming
HTTP requests can reuse the same instance of the
HttpHandler

21. Convert from an HTML to an aspx page

22. HttpHandlers to custom file
extensions
 Create a class that inherit from
IHttpHandler, add it to App_code or in
a separate library project to be added
as an assembly
 Implement the 2 methods same as
previously
 Add configuration to web.config

25. Convert from an HTML to an aspx page

26. Deployment

28. Publish on Local IIS
 Must run Visual Studio as
Administration
 Install all needed IIS components
 Reinstall ASP.NET if needed
 Make sure application pool is set to
.NET Framework 4.0
 Add user(with permissions to db and
files) to application pool identity

29. Publish on Local IIS
 Use Copy Website
 Use Publish Website

30. Important Note
 To avoid problems with configuration
in machine root web.config
◦ Add <clear /> in all providers
 To avoid problems with users and
roles in multiple applications add
applicationName attribute to all
providers

31. Reading Assignment #8
 Chapter 26 – Professional ASP.NET 4
in CS and VB

32. REFERENCES
 [1] Beginning ASP.NET 4 In C# 2010, Matthew
Macdonald, Apress
 [2] Web Application Architecture
Principles, Protocols And Practices, Leon Shklar
And Richard Rosen, Wiley
 [3] Professional AS P.NE T 4 In C# And VB, Bill
Evjen, Scott Hanselman And Devin Rader, Wiley
 [4] Pro ASP.NET In C# 2010, Fourth
Edition,matthew Macdonald, Adam Freeman, And
Mario Szpuszta, Apress