Referring to specific information inside an XML document is a little like finding a needle in a haystack: how do you differentiate the information you need from everything else? XPath and XPointer are two closely related languages that play a key role in XML processing by allowing developers to find these needles and manipulate embedded information. XPath describes a route for finding specific items by defining a path through the hierarchy of an XML document, abstracting only the information that's relevant for identifying the data. XPointer extends XPath to identify more complex parts of documents. The two technologies are critical for developers seeking needles in haystacks in various types of processing. XPath and XPointer fills an essential need for XML developers by focusing directly on a critical topic that has been covered only briefly. Written by John Simpson, an author with considerable XML experience, the book offers practical knowledge of the two languages that underpin XML, XSLT and XLink. XPath and XPointer cuts through basic theory and provides real-world examples that you can use right away. Written for XML and XSLT developers and anyone else who needs to address information in XML documents, the book assumes a working knowledge of XML and XSLT. It begins with an introduction to XPath basics. You'll learn about location steps and paths, XPath functions and numeric operators. Once you've covered XPath in depth, you'll move on to XPointer--its background, syntax, and forms of addressing. By the time you've finished the book, you'll know how to construct a full XPointer (one that uses an XPath location path to address document content) and completely understand both the XPath and XPointer features it uses. XPath and XPointer contains material on the forthcoming XPath 2.0 spec and EXSLT extensions, as well as versions 1.0 of both XPath and XPointer. A succinct but thorough hands-on guide, no other book on the market provides comprehensive information on these two key XML technologies in one place.