The XSL Companion

From the Book: This book covers a family of standards developed by the W3C (World WideWeb Consortium). These standards emerged out of a proposal for astylesheet language, submitted in 1997, which was to be called XSL(eXtensible Stylesheet Language). However, during its gestationthis proposal was pulled apart and became three separate standards.XPath defines a mechanism for locating information in XML documents,and has many other uses beyond its role in formatting documents.XSLT (XSL Transformations) provides a means for transforming XMLdocuments into other data formats, including (but not limited to)formatting-focussed markup languages. Finally, the term kXSLm isnow properly used only to name a standard for embedding XML-basedformatting information in documents. Due to their shared history, these three standards are still relatedand are used together to provide a means to format XML documents,especially in preparation for the particular demands of presentationon print media. The XSLT standard includes XPath constructs in a numberof places, and can be used to convert an XML document that conforms toan arbitrary document model into an XSL document. But each standard canalso be used alone or with alternative technologies. Because the XSLformatting language is less mature than XSLT, and not yet well supported,XSLT is initially being used primarily to convert XML documents in toHTML (or XHTML) documents, possibly enhanced with CSS(Cascading Style Sheets) styling instructions. Both of these formats are thereforeexplained in depth. When formatted documents have to be edited before they can be presentedor printed, it is necessary to use aword processor or DTP package,but none of these packages yet support XSL as an import format.Two popular import formats existing today are RTF (Rich Text Format) andQuark Tags. Issues concerned with the use of XSLT to convert XMLdocuments into these two formats are discussed.Second edition Since the release of the first edition of this book, almost two years ago,much has happened to warrant the creation of a second edition. The XSLT standard is now firmly established as a companion to XML forall manner of transformation needs, and experience of using thisstandard to solve serious practical problems has resulted in moreexplanatory material and suggestions on how to exploit it to the full. Because XSLT makes heavy use of XPath, its popularity has also helpedestablish XPath as the way to navigate through XML documents.XPath is now being incorporated into XML databases as a query language.It therefore deserves more prominence and now has a section of the bookto itself. The XSL standard has now progressed to Recommendation status.This edition covers the final release.Acknowledgements Thanks to Rubus for support in developing this book,and to Katherin Ekstrom at Pearson Education. The many individualswho have worked together to develop the standards covered in thisbook richly deserve acknowledgement. Finally, thanks once again toAdobe for FrameMaker+SGML (which was used both in the preparationand publication of this book). Feedback Comments and suggestions for a possible future edition are welcomed. Updates,additions and corrections can be obtained from the authorms Webpage Neil Bradley - April 2002