Getting started with xpath

Remarks#

XPath is a language for addressing parts of an XML document.

It is used in XSLT and is a subset of XQuery. Libraries are available for most other programming languages as well.

XPath is an international standard with specifications published by W3C:

XPath 1.0: XML Path Language (XPath), Version 1.0
XPath 2.0: XML Path Language (XPath) 2.0 (Second Edition)
XPath 3.0: XML Path Language (XPath) 3.0

Versions#

Version	Release Date
1.0	1999-12-16
2.0	2007-01-23
3.0	2014-04-08
3.1 (W3C Candidate Recommendation)	2015-12-17

Sample XML (without namespaces)

Here is some sample XML against which example XPaths can be written:

<r>
  <e a="1"/>
  <f a="2" b="1">Text 1</f>
  <f/>
  <g>
    <i c="2">Text 2</i>
    Text 3
    <j>Text 4</j>
  </g>
</r>

Select text

For the sample XML (without namespaces):

This XPath,

/r/f/text()

will select the text node with this string value:

"Text 1"

And this XPath,

string(/r/f)

will return the string value of f, which is also:

"Text 1"

Select an element

For the sample XML (without namespaces):

This XPath,

/r/e

will select this element:

<e a="1"/>

Common HTML Operations

If the input HTML DOM is

<html>
    <body>
        <a>link</a>
        <div class='container' id='divone'>
            <p class='common' id='enclosedone'>Element One</p>
            <p class='common' id='enclosedtwo'>Element Two</p>
        </div>
    </body>
</html>

Find an element with a specific id in the entire page

//*[@id='divone'] # Returns <div class='container' id='divone'>

Find an element with a specific id in a particular path

/html/body/div/p[@id='enclosedone'] # Returns <p class='common' id='enclosedone'>Element One</p>

Select an element with a particular id & class

//p[@id='enclosedone' and @class='common'] # Returns <p class='common' id='enclosedone'>Element One</p>

Select the text of a particular element

//*[@id='enclosedone']/text() # Returns Element One

Testing Xpaths in browser console

A quick way to test your xpath is in your browser developer tool console.

Format is

   $x('//insert xpath here')

$ - specifies it is a selector.

x - specifies it is using xpaths

Example:

$x("//button[text() ='Submit']")

When this command is entered it will return all occurrences of elements that are buttons with text equal to Submit.