Chapter 10 -- Using Active Server Pages

Chapter 10

Microsoft Active Server Pages (ASP), a feature of Microsoft Internet Information Server (IIS) (in versions 3 and later) provides an application framework for developing powerful, server-based functionality for a Web site. Because the logic for ASP runs on the Web server, applications built using ASP can be accessed from a variety of Web browsers running across different platforms.

ASP provides the following core functionality:

• Server-side scripting You can embed scripting such as Microsoft VBScript (Visual Basic, Scripting Edition), Microsoft JScript, Perl, or other language syntax directly in an HTML page for execution on the Web server as opposed to the Web browser.
• Flexible Web-to-database connectivity Through server-side scripting and Microsoft ActiveX Data Objects (ADO), you can easily build rich database functionality into your Web sites.
• State management You can track and manage application state on a per-user, per-application, and per-server basis using built-in objects. Using the built-in objects helps you overcome the limitations of the stateless Hypertext Transfer Protocol (HTTP) for building rich Web applications.
• Active Server components Perhaps most important, you can instantiate and use programmable components. You can create these components using tools such as Microsoft Visual Basic, Microsoft Visual C++, Microsoft Visual J++, Borland Delphi, and Powersoft PowerBuilder. This lets you integrate Web applications with existing client/server systems.

ASP works with the following Microsoft Web servers:

• IIS 3 on Microsoft Windows NT Server 4
• IIS 4 on Windows NT Server 4
• Microsoft Peer Web Services on Windows NT Workstation 4
• Microsoft Personal Web Server on Microsoft Windows 95, Windows 98, or Windows NT Workstation 4

IIS 4 and the Personal Web Server for Windows 95, Windows 98, and Windows NT Workstation 4 are included in the Windows NT Option Pack that can be downloaded or purchased from Microsoft. The Option Pack is the easiest way to install IIS or the Personal Web Server and its related applications, such as Microsoft Transaction Server (MTS).

You can use server-side scripting to easily create dynamic content—content that responds to circumstances such as user-supplied information requests, personal profiles, or conditional logic. With server-side scripting, the same physical Web page can be customized differently every time it is downloaded. You can also use server-side scripting to dynamically generate client-side interactivity. For instance, you can detect whether the browser being used supports Java, and you can then decide whether to include a Java applet within the Web page before sending it to the browser.

To date, Common Gateway Interface (CGI) programming has typically been used to provide server-based intelligence within Web applications. However, CGI programs are typically complex and inflexible. With server-side scripting and ASP, you can leverage Visual Basic or JScript programming experience and more quickly create rich applications for the Web.