In ASP+, all the configuration details for all Web applications are kept in human-readable files named config.web. The default config.web file is in the Program FilesComPlusv2000.14.1812 directory and this specifies the settings that apply to any applications or directories that do not over-ride the defaults. The standard format for the configuration files is XML, and each application inherits the settings in the default config.web file.

The config.web file specifies a whole range of settings for the application, including the HTTP Modules and Request Handlers that are to be used to handle each request. This provides a completely extensible and flexible architecture, allowing non-standard HTTP protocol handling to be carried out if required. We examine configuration files and their use in Chapter 6.

The Application Definition File – global.asax

As in ASP 2.0 and 3.0, it is also possible to use a definition file that specifies the actions to take when an application starts and ends, and when individual user sessions start and end. This file is named global.asax (note the .asax file extension), and is stored in the root directory for each application.

The existing ASP event handlers Application_OnStart, Application_OnEnd, Session_OnStart, and Session_OnEnd are supported in global.asax, as well as several new events such as Application_BeginRequest, Security_OnAuthenticate, and others. And, as before, the global.asax file can be used to set the values of global or session-level variables and instantiate objects. We look at the use of global.asax files in Chapter 6.

ASP+ Application and Session State

One of the useful features in previous versions of ASP that developers were quick to take advantage of was the provision of global and user-level scope for storing values and object instances. This uses the Application and Session objects in ASP, and these objects are still present in ASP+. Although backwards compatible, however, the new Application and Session objects offer a host of extra features.