XSLT

XSLTs are the method used to transform raw XML data into useful content[11] - creating a Word document or a FrameMaker document from the same source files is accomplished by applying two different XSLTs to the same XML data files. 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. The reason for this is quite simple: consistency. When you make a change to the source content of a series of deliverables, you should be able to produce those new versions with a minimum of intervention; ideally with no intervention. This is accomplished by creating an XSLT for each document instance type and then processing content through that common XSLT for all versions of that output deliverable type. The same revised content can be processed through XSLTs to produce an update for four different courses, which may be either web-based or paper-based.

This is a departure from traditional word processing and publication tools, which 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 content with format, but all formatting is defined in the XSLT, which authors very seldom modify. Rather than spending endless hours fiddling with documents to make the styles come out right, developers work with the content to make that right. When the words and graphics are right, they are done.

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 are parsed⁵ to become a web site. The website 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 fully featured web content.

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

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 Structured Query Language (SQL) query to the database.

You may have all your content about a subject in XML format and use an XSLT to separate out from the total content only those passages which conform to specific criteria.