Learning XML

Chapter 6. Transformation: Repurposing Documents

Your XML document is a well-organized container of information, yet it still seems static. After all the trouble of massaging your data so that it's well-formed XML and (optionally) conformant to a DTD, are you stuck now with another dead-end format that you can't use elsewhere? Sure, a document format such as DocBook is useful in representing information structurally, but aren't you still tied down to software applications specifically made to handle it? What if you want to see the document in an HTML browser that doesn't support XML? Or output it as text for printing? Are you at the mercy of software developers for this functionality?

Don't worry—XML hasn't let you down. In fact, it has opened doors for you. The clean, unambiguous representation of text elements makes it easy to repurpose a document. Other formats, such as Microsoft Word, HTML, and troff rely so heavily on presentational properties that it is difficult to see any structure, making it almost impossible to automatically adjust anything without damaging the content. Fortunately, with XML you're on strong footing, and the sacrifice you made to get here will pay for itself with flexibility of form and data integrity.

This is the most exciting chapter of the book, because it shows how XML, with its strict rules and high startup cost, gives you more possibilities for using the data in your document later and for applications that do searches, queries, and other sophisticated ...