This tutorial helps you to learn: What is XML Path Language (XPath); Data Types, Literals and Variables; Evaluation Context Build-in Functions; Expressions and Location Paths; Using XPath in XSL Templates.

The XPath processor allows you to retrieve a subset of an XML document. A query, which is always an XPath expression, returns a well-formed XML node-list or an XPath value object. In XPath 2.0, an expression returns a sequence of XML nodes and/or XPath value objects. This XPath tutorial covers the following topics:

About the XPath Processor, Sample Data for Examples and Testing, Getting Started with XPath Queries, Specifying the Nodes to Evaluate, Handling Strings and Text in XPath, Specifying Boolean Expressions and Functions, Specifying Number Operations and Functions, Comparing Values, Generating XPath, 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.

This XPath tutorial covers: How an XPath processor works, sample data for XPath Examples and Testing, Getting Started with XPath queries, Specifying the XML Nodes to Evaluate, XPath strings and text processing, XPath Expressions and functions, XPath Number Operations and Functions, comparing values in XPath, finding a particular node Obtaining a union, obtaining information About a Node or a node set Using XPath expressions in XSLT stylesheets, accessing other documents During Query execution, and an XPath reference guide.

XPath is described in XPath 1.0 standard. In this tutorial selected XPath features are demonstrated on many examples.

XPath is everywhere. It's established itself as the workhorse of XML processing. The XPath engine is one of the parts of 4Suite that has had the most development and exercise. Much of it is implemented in C for performance sake, and this is one of the key differences between the XPath library in current 4Suite and that in PyXML, which is based on an older release of 4XPath, and is almost entirely in Python.

In this tutorial, selected XPath features are demonstrated with many examples and pictures which can be downloaded for off-line use.

This tutorial introduces XPath and covers most aspects of it. It is aimed at people who do not know XPath or want a refresher. If you plan to use XSLT, you should take this tutorial first. You will learn: What XPath is, the syntax and semantics of the XPath language, how to use XPath location paths, how to use XPath expressions, how to use XPath functions, and how XPath relates to XSLT. XPath is a W3C standard. This tutorial covers version 1.0.

Values of attributes can be used as selection criteria. Function normalize-space removes leading and trailing spaces and replaces sequences of whitespace characters by a single space.

XML path expressions Tutorial. [PPT]

What is XPath ? [PPT]

XPath is a standard, confirmed by the World Wide Web Consortium (W3C) as a common language to access XML documents. The language is much more powerful than XML DOM, wich reults in much, much less code to write.

A module that provides an XPath matching condition for packet filtering.

The purpose of this tutorial is to show how authors can extend the basic XPath library with their own functions using COM.

Tutorial with 23 XPath examples illustrated by step-by-step instructions and XML source code. Tutorial may be viewed online or downloaded.

XPath and XSLT Tutorial [PDF]

Our experimental analysis of several popular XPath processors reveals a striking fact: Query evaluation in each of the systems requires time exponential in the size of queries in the worst case. We show that XPath can be processed much more eciently, and propose main-memory algorithms for this problem with polynomial-time combined query evaluation complexity. Moreover, we present two fragments of XPath for which linear-time query processing algorithms exist.

Transforming XML documents is one of the hottest topics in the XML community today. XML's flexibility allows users to create simple, descriptive tags; for effective data interchange, those tags must be transformed into another set of tags. The most common transformation is converting an XML document into HTML so it can be viewed in a browser. However, as new XML vocabularies emerge, other transformations will become popular as well. The World Wide Web Consortium (W3C) is currently working on two proposed standards for transforming XML documents: XSLT and XPath. To help you understand these important standards efforts, we're pleased to present an introductory version of Ken Holman's "Practical transformation using XSLT and XPath (XSL transformations and the XML Path Language)."

Based on an analysis of several large XML projects, this article examines how to make effective and efficient use of DOM in Java. The DOM offers a flexible and powerful means for creating, processing, and manipulating XML documents, but it can be awkward to use and can lead to brittle and buggy code. Author Parand Tony Daruger provides a set of Java usage patterns and a library of functions to make DOM robust and easy to use.

This tutorial introduces XPath and covers most aspects of it. It is aimed at people who do not know XPath or want a refresher. If you plan to use XSLT, you should take this tutorial first. You will learn: What XPath is, the syntax and semantics of the XPath language, how to use XPath location paths, how to use XPath expressions, how to use XPath functions, and how XPath relates to XSLT. XPath is a W3C standard. This tutorial covers version 1.0.

The problem: You want to take advantage of the power and simplicity that XML tools can offer, but you face a site full of aging HTML documents. The solution: Convert your documents to XHTML and put Perl and XML::XPath to work.