SOAP Web Services
The Random Bushism section of this site is offered as a Web service, as is the Random Google image search at http://www.ghettodriveby.com
Some poor, uncitable author at IBM put it much more concisely than I ever could: Web Services are self-contained, modular applications that can be described, published, located, and invoked over a network, generally, the World Wide Web.
I fell into Web services by fluke when working on an e-com project in early 2003. We were using a third party payment gateway and wanted to make the transaction process as seamless as possible to the end user. This involved pre-processing the data before sending it to the payment gateway provider and catching any errors the gateway returned, all the while keeping control of the look and feel.
My initial attempts involved posting information behind-the-scenes and doing a screen scrape of the resulting HTML - a nasty hack. While commiserating with a developer working for the payment gateway provider, I learned that they were rolling out a beta version of a Simple Object Access Protocol (SOAP) interface to their service. So, I read up on this new beast and built my first Web service client. Then, a couple of months later, I built my first Web service.
The potential for Web services is huge. Whereas an organization used to guard its internal processes or data, it can now leverage these resources, for a profit, without unduly exposing itself. And bolting on a SOAP interface to existing code has proven deceptively easy. Web services can be daisychained, allowing a developer to focus on business rules specific to his domain, while using resources (data and logic) from other domains.
A good example of this is the mapping service provided by ArcWeb. I neither have the time nor the genius to create my own GIS system. And why should I? ArcWeb has already done it for me . . .
