• Chapter 1: Getting Started with Stylus Studio®
• Chapter 2: Editing and Querying XML
• Chapter 3: Converting Non-XML Files to XML
• Chapter 4: Working with XSLT
• Chapter 5: Creating XSLT Using the XSLT Mapper
• Chapter 6: Debugging Stylesheets
• Chapter 7: Defining XML Schemas
• Chapter 8: Defining Document Type Definitions
• Chapter 9: Writing XPath Expressions
  • About the XPath Processor
    • Where You Can Specify Queries
    • About XPath
    • Benefits of XPath
    • Internationalization
    • Restrictions on Queries
  • Sample Data for Examples and Testing
  • Getting Started with Queries
  • Specifying the Nodes to Evaluate
  • Handling Strings and Text
  • Specifying Boolean Expressions and Functions
  • Specifying Number Operations and Functions
  • Comparing Values
  • Finding a Particular Node
  • Obtaining a Union
  • Obtaining Information About a Node or a Node Set
  • Using XPath Expressions in Stylesheets
  • Accessing Other Documents During Query Execution
  • XPath Quick Reference
• Chapter 10: Working with XQuery in Stylus Studio
• Chapter 11: Composing Web Service Calls
• Chapter 12: Accessing Relational Data as XML
• Chapter 13: Integrating with Third-Party File Systems
• Chapter 14: Extending Stylus Studio
• Chapter 15: Stylus Studio GUI Reference

Home > Online Product Documentation > Table of Contents > About XPath

About XPath

XPath is a notation for retrieving information from a document. The information could be a set of nodes or derived values.

XPath allows you to identify parts of an XML document. In addition, a subset of XPath allows you to test whether or not a node matches a particular pattern. XPath provides Boolean logic, filters, indexing into collections of nodes, and more.

XPath is declarative rather than procedural. You use a pattern modeled on directory notation to describe the types of nodes to look for. For example, book/author means find all author elements that are contained in book elements.

XPath provides a common syntax for features shared by Extensible Stylesheet Language Transformations (XSLT) and XQuery. XSLT is a language for transforming XML documents into XML, HTML, or text. XQuery builds on XPath and is a language for extracting information from XML documents.

The basic syntax for XPath mimics the Uniform Resource Identifier (URI) directory navigation syntax. However, the syntax does not specify navigation through a physical file structure. The navigation is through elements in the XML tree.