Page #31 (Chapter 3 - Building ASP Applications)

	Chapter 4 - Introduction to WebClasses
	Visual Basic Developers Guide to ASP and IIS
	A. Russell Jones

Copyright 1999 SYBEX Inc.

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	Chapter 4: Introduction to WebClasses

	Overview

	The way you interact with Internet Information Server from a Visual Basic application is with a special type of class called a WebClass. WebClasses are new in Visual Basic 6. They work hand in hand with Active Server Pages to provide server-based request processing.

	Let me interject here that there's nothing that WebClasses can do that you can't do yourself! If that's so, then what's the point? Why not just write ActiveX DLLs that work with ASP pages and forget the WebClass? Better yet, why not just use ASP so you don't have to compile, install, and register binary code?

	The point is that WebClasses handle a great deal of the grunt work of connecting your VB class to the Web server, parsing the variables sent by the browser, and sending new content to the browser. More important, WebClass code, like a DLL, is compiled code; therefore, in certain situations, it's considerably faster than the interpreted ASP code. Still more important, WebClasses encourage separation between the interface code and the application logic. A WebClass acts as the connection point between the user interface (HTML) and back-end databases or middle-tier business objects. Finally, WebClasses let you work in a robust environment that you are familiar with and that has evolved over many years.

	In this chapter, you'll see how WebClasses work hand in hand with IIS and the ASP objects to make it easy to provide dynamic information to the browser. You'll also see the importance of optimizing your code to ensure that your application responds quickly and scales well. Finally, you'll see the relative advantages and disadvantages of using WebClasses as opposed to using ASP pages, so you can decide which technology is appropriate for your applications.