Chapter 13. Navigation (XPath)

The ability to navigate through XML documents is vital to many applications of XML, including the querying of XML documents to find and retrieve required material, the creation of hypertext links to objects that do not have unique identifiers, the merging of documents and document fragments, and the formatting of document components for presentation. The XPath standard has been incorporated into several XML-related standards, including XPointer, XSLT, XML Schema, and indirectly by the XInclude standard. Readers intending to cover one or more of these topics are advised to read this chapter first. Standard-specific extensions are explained in the relevant chapters. Chapter 35 provides a series of maps that explore the XPath standard in fine detail, but these maps are best explored after reading this chapter.