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.
John E. Simpson's forte is taking obscure bits of technical information and making them accessible. He is the author of Just XML, now in its second edition, and Just XSL (Prentice Hall), as well as XML.com's monthly XML Q&A column. John has been working with XML, XSL, and XPath since the technologies first emerged.
Preface 1. Introducing XPath and XPointer Why XPath and XPointer? Antecedents/History XPath, XPointer, and Other XML-Related Specs XPath and XPointer Versus XQuery 2. XPath Basics The Node Tree: An Introduction XPath Expressions XPath Data Types Nodes and Node-Sets Node-Set Context String-Values 3. Location Steps and Paths XPath Expressions Location Paths Location Steps Compound Location Paths Revisited 4. XPath Functions and Numeric Operators Introduction to Functions XPath Function Types XPath Numeric Operators 5. XPath in Action XPath Visualiser: Some Background Sample XML Document General to Specific, Common to Far-Out 6. XPath 2.0 General Goals Specific Requirements 7. XPointer Background XPointer and Media types Some Definitions The Framework Error Types Encoding and Escaping Characters in XPointer 8. XPointer Syntax Shorthand Pointers Scheme-Based XPointer Syntax Using XPointers in a URI 9. XPointer Beyond XPath Why Extend XPath? Points and Ranges XPointer Extensions to Document Order XPointer Functions A. Extension Functions for XPath in XSLT Index