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XSL and XSLT

XSL is the language used to create transformations (XSLT). XSLTs are the method used to transform raw XML data into useful content[13]. They are referred to as style sheets, but they are not style sheets in the same way as a cascading style sheet defines the look of an HTML document instance.

It is important to note that authoring in XML divorces the content from the format. This is a departure from traditional word processing and publication tools, which attempted to merge these two operations into a single work flow. Some tools used to author XML, such as FrameMaker allow the designer the illusion of authoring of content with format, but all formatting is defined in the XSLT, which authors very seldom tinker with. The reason for this is quite simple: consistency. When you make a change to the source content of a series of deliverable instance documents, you should be able to produce those new versions with a minimum of author intervention; ideally with no intervention. This is accomplished by creating an XSLT for each instance document type and then processing content through that common XSLT for all versions of that output deliverable type.

\includegraphics[width=5in]{Images/xslta.eps}

XML is data and contains no formatting. However, because it is structured data, the formatting can be applied to it programmatically. The XML data and the XSLT is parsed2 to become a web site. The web site contains the HTML pages, images, javascripts, style sheets and other content associated with a full featured web site. The same content can be parsed with a different XSLT to result in WAP Web content or a Microsoft Word document.

\includegraphics[width=5in]{Images/xsltb.eps}

An XSLT can also convert the same content to an MS-Word document (or any other document format desired).

\includegraphics[width=5in]{Images/xsltc.eps}

Lastly, an XSLT can be used as an intelligent query to result in the XML content that conforms to a specific set of rules. These rules can be very complex and can be a more efficient way to query data than a direct SQL query to the database.


next up previous index
Next: What about ...? Up: XML Basics Previous: Document Type Definitions (DTD)   Index
root 2003-07-21