The popularity of Microsoft's Active Server Pages (ASP) technology is growing rapidly. Part of the reason is ASP's flexibility: the output of ASP scripts is most commonly HTML, which is included in the text stream returned to the client, making it a convenient way of creating browser-independent web content. But an additional reason--and one that will become more and more important over time, as webapplications replace web pages--is its extensibility. And the most effective way to extend ASP is to develop custom ASP components.

However, the techniques for developing custom ASP components, along with the snags and pitfalls of developing custom components, are not well documented. In addition, to successfully develop ASP components one must be a jack-of-all-trades: programming requires some knowledge of COM, of threading models, and of the ASP object model, as well as a mastery of one or more language tools and development environments.

That's where Developing ASP Components comes in. The first section of the book explores the topics all developers need to know to develop components for ASP effectively:

• The configuration of the ASP development environment
• ASP components and the Component Object Model (COM)
ASP components and threading models
• ASP components and the Microsoft Transaction Server, which can be used to provide a variety of services to ASP components
• The objects, properties, methods, and events available in the ASP object model

Because more and more developers find themselves using more than a single language tool, the remaining three sections of the book each focus on ASP component development using any of the three major development tools: Microsoft Visual Basic, Microsoft Visual C++ and the ActiveX Template Library (ATL), and Microsoft J++. Each section carefully focuses on the issues that concern the ASP component developer who is using that particular development environment. These include:

• Accessing ASP's intrinsic objects
• Accessing data using either OLE DB (in the case of C++) or ADO (in the case of VB and J++)
• Creating n-tier web applications with VB
• Handling persistence using MFC along with Visual C++/ATL
• Accessing native code (the Windows libraries, which are written in C) from J++

This thorough coverage of the background information needed for developing ASP components, as well as its focus on the component development in each of three major development environments, makes Developing ASP Components the definitive resource for the ASP application and component developer.