XSLT: The Driving Force Behind XML
- By Mark McFadden
When you consider Web services it’s natural – perhaps obligatory – to focus on the combination of XML and HTTP. In this column, The eXtended Enterprise, I’ll be focusing on XML and the family of standards and services that have blossomed around it.
XML is a focal point for those providing Web services. For service providers, working with XML is as simple as hosting Web pages. For application builders the simplicity of the XML and the Web provides huge advantages over other, overhead-laden technologies.
While the focus, for those building and using Web services, is often on XML, there’s another crucial technology that needs to be followed: XSLT.
In the alphabet soup that is standards for Web services, XSLT is the standard that is, in a real way, all things to all people. XSLT stands for the ungainly, eXtensible Stylesheet Language for Transformations. Forget the acronyms! XSLT is the standards based language that lets Web services turn XML documents into something else – almost anything else.
Perhaps that doesn’t sound too compelling. Consider this!
Web services are usually crucial components of larger Web applications. Those Web applications typically deliver services between servers or between servers and end users. Today we concentrate on building solutions that talk to common Web servers and ordinary desktop browsers. Tomorrow the same applications will need to be delivered to Palm Pilots, mobile phones, and a variety of mobile, wireless and alternative devices.
It would be great if we could build Web services once and then adapt the results to whatever business devices are in use – or in vogue! That’s what XSLT does.
There can be no denying that XML makes cross-platform database applications easier. Wouldn’t it be easier still if, when business partners use different databases, they could create a common XML schema and then simply rewrite the documents from XML into SQL statements, import macros, or whatever language was needed for getting the data and logic into a target database? That’s what XSLT does.
One of the huge benefits that comes with the emergence of Web services is the infinite adaptability and applicability of HTTP and structured documents. Imagine how much simpler things would be if there was a language that could capitalize on that adaptability by keeping content in one standard format while adapting it for whatever presentation or application was required on-the-fly. As it turns out, that’s just what XSLT does.
XML is the foundation of Web services. It’s the tool that provides the intelligence to make sense of data on the Web. But intelligence is not enough – data has to be altered and adapted to make it useful. XSLT is one of the “hidden” technologies of Web services. While XML and the business communications – like SOAP – get all the attention, there’s one technology that stands to transform Web services.
That’s just what XSLT does.
Mark McFadden is an Internet infrastructure consultant based in Madison, Wisc. He writes on Internet technologies and standards.