Beginning XML, 5th Edition

Chapter 8

XSLT

WHAT YOU WILL LEARN IN THIS CHAPTER:

• What XSLT is used for
• How writing XSLT code is different than writing code in traditional languages
• The basic XSLT constructs
• How XSLT uses XPath
• The more advanced XSLT constructs
• XSLT 2.0 improvements
• The future of XSLT

XSLT stands for Extensible Stylesheet Language Transformations and is one of the big success stories among the various XML technologies. In this chapter you’ll find out why there is constant need for transformations from one XML format to another, or from an XML format to a plain text document. You will see how XSLT, as a declarative language (you tell it what you want done in a specific circumstance and you let the XSLT processor decide how it should be done), differs from the majority of common coding languages such as Java and C# because they are procedural (essentially a series of low-level instructions on how to manipulate data). You’ll then be introduced to the mainstay of XSLT, the template, and see how judicious use of this makes processing XML simpler than having to provide detailed instructions. You will also see how XSLT is a functional language where results are defined as the result of function calls, rather than data being directly manipulated. Programming with declarative, functional languages can take some getting used to; it needs a different mindset from that used in procedural code, and this puts off many people when they start with XSLT. You shouldn’t fall into that group because the examples ...