Active Server Pages 2.0

Active Server Pages is a technology centred on Microsoft Windows NT4 and IIS (Internet Information Server) that allows dynamic interaction between HTML pages on the internet or an intranet, and a server. Contexts in which this technology could be used for example might be e-commerce where ordering and credit card transactions need to be processed or perhaps a help desk application where high levels of dynamic user-interaction are required. Functionality of this sort has previously been implemented using CGI or IDC scripts, but the proponents of ASP maintain that the former are more resource-intensive and less flexible.

We are assured by the authors (their comments at this point are ascribed to "a few ideas we found floating around in the developer community") that fortunately the users of this new technology "don't have to abandon their CGI apps, IDC script and custom components straight away (as long as they'll run on IIS of course)." ASP and many of its technologies are now based on Microsoft's COM object model, having had humble origins as a simple redirection and verification tool.


COM enables OLE automation, which is the controlling of an object or application by another application, or indeed by a script. The ASP object model is covered in detail with examples of what the methods of the ASP object can accomplish through manipulating, or being manipulated by scripts.

ASP works in conjunction with scripts. These are pieces of code embedded in HTML pages that are parsed from the page prior to it being interpreted, as opposed to static, text-centred HTML that returns the same page each time it runs with no interactive possibilities. Scripts may run on either the server or the client, or at both ends. Examples are given of how client-side scripting can be used in the validation of user input in order to minimize network traffic and total processing time.

Normally the bulk of processing would be conducted on the server, one of the main reasons being that the server is frequently accessing a database. It is for this reason that extensive coverage is given of Microsoft's Active Data Object, a COM technology with a thorough analysis of the ADO object model and its ability to manipulate databases.

The latest development built on ADO is OLE-DB, which promises the structure necessary to provide a uniform interface to potentially heterogeneous data. This includes the capability of querying data sources such as mail sources and flat files that do not usually provide a query interface. A whole chapter in an appendix is devoted to this exciting-sounding technology in one of its latest commercial incarnations.

The book is a very comprehensive view of ASP, necessarily in conjunction with related software engineering developments. Necessarily because ASP can be seen as a synthesis of related technologies. Indeed, we are told that one mysterious idea, floating around in the developer community is that -

"ASP isn't an application. It's a 'quick fix' glue technology that might just manage to stick together all the variably useful bits that are falling out of Microsoft together, in a way that's convincing enough to make people buy Windows NT Server."

The authors seem to have covered the most important of these disparate elements, devoting adequate space to such important issues as security and encryption. Plentiful examples are given, although unfortunately, apart from a couple of token examples using JavaScript (the default client-side ASP scripting language) the examples are given in VBScript. Perhaps the examples might at least be made available as JavaScript on the Wrox web site?

The approach is eminently practical and aimed at the developer, with four chapters of real-world case studies. Perhaps a little space could have been found for an 'under-the-hood' analysis of Microsoft's COM implementation in the context under discussion. This would have been beneficial for developers familiar with COM technology but as yet unfamiliar with ASP and ADO and the implementation of their COM interfaces. All in all though, this book is highly recommendable and would be a useful addition to the library of any web developer.