Programming Web Services with XML-RPC


Authors: Simon St Laurent, Ed Dumbill, Joe Johnston & John Posner

ISBN:

0596001193

Publisher: O'Reilly

Reviewed by: Dean Wilson

Programming Web Services with XML-RPC is a slim concise volume that cuts out a lot of the current XML hype that plagues too many recent books and is all the better for its absence. The first two chapters of the book contain an overview of the XML-RPC standard itself and provide both a good overview of the technology and a flavour of the current implementations.

The second chapter gives enough technical information to make debugging a lot simpler and provides the basic grounding you would need to write an implementation of the protocol if you can find a language that doesn't currently have support (No small task!).

Chapters three through seven form the bulk of the book, each chapter covers implementing both clients and servers using different languages toolkits. The languages covered in this section are Java, Perl, PHP, Python and a chapter on ASP, VBScript and (Pretty much in name only) COM.

The chapters most relevant to me were the Perl chapter, which I found easy to get into and provided what I consider a good starting point to making your own Perl based XML-RPC apps and the ASP/VBScript chapter.

The ASP VBScript chapter is the only language focused one in the book that breaks the books own format, it covers both the VBScript code and also uses Perl for testing both ends of the connection. My only disappointment with this chapter is that it relegates the mention of the COM based XML-RPC library to two paragraphs tucked away at the end of the chapter and does no more than acknowledge its existence and provide a link. Adding another small section covering its use with something like Visual Basic would have been a welcome addition.

The final chapter off the book does a little evangelism (And if you made it this far and don't see the need for XML-RPC then this won't sway you) as well as pointing out some of the considerations you need to be aware of with XML-RPC such as authentication and state. This has a brief explanation of other related technologies such as SOAP and WSDL following it before closing the meat of the book and leading on to the two appendixes.

Both of these provide a brief and very to the point description of the fundamentals that you need to know in XML and HTTP to make your way through the second chapter of the book. While they are both useful they don't rid the world of the need for the HTTP and XML pocket references, although it is good form for O'Reilly to not just put in a line at the start of the book plugging their other titles.

My main issue with the book is one of the reasons I like it so much, with over two thirds of the book dedicated to different language implementations of the protocol if you only know one of the languages covered then you may not get full value for your money since a large chunk of the book will sit unread. The book is however a good introduction and an easy read on a subject I've yet to covered adequately elsewhere.

Something I do feel needs a special mention is the foreword. While the forewords in most books are a little pointless Dave Winer, one of the main men in the XML-RPC and SOAP worlds, has penned this one and it's difficult to read it without picking up on some of his enthusiasm for the subject matter. Its only a small thing but it adds a nice touch to the book.