Finding Elements by Content in a DOM Document Using XPath
XPath is an expression language for selecting nodes in an XML file.
See Finding Elements by Absolute Location in a DOM Document Using XPath for common XPath
expression for selecting elements. This example adds to those
examples by demonstrating the ability to select elements based on their
content.
In an element such as <A>cat</A>, the content is simply
"cat". However, in the case of an element that contains other
elements, the content is the concatenation of the content of all
subelements. For example, in the XML fragment
<A>cat<B>,<C>dog,</C>and</B>rat</A>,
the content of A is "cat,dog,andrat".
This example demonstrates some common uses of expressions that
use element content; for more information on XPath, see the
specification at http://www.w3c.org/TR/xpath. In the example,
the result of an XPath expression is shown next to the expression; the
numbers are ids of elements in the sample file shown at the end of the
example.
XPath 1.0 does not support case-insensitive matches. However,
a simple case-insensitive match can be done using the translate()
function, which converts a string by mapping one character into another:
To execute an XPath expression, see
Finding Elements by Absolute Location in a DOM Document Using XPath. Here is the sample XML file
used in the example:
// Get all elements that equal the string cat
String xpath = "//*[.='cat']"; // 2 6
// Get all elements that equal the string dog
xpath = "//*[.='dog']"; // (none)
// Note that element #3 does not match because its
// content is " dog " rather than "dog"
// Get all elements that contain the string cat
xpath = "//*[contains(.,'cat')]"; // 1 2 4 5 6
// Get all elem3 elements that contain the string cat
xpath = "//elem3[contains(.,'cat')]"; // 6
// Get all elements that contain the string cat,
// ignoring the contents of any subelements
xpath = "//*[contains(child::text(),'cat')]"; // 2 4 6
// Get all elements without subelements and whose contents contains the string cat
xpath = "//*[count(*)=0 and contains(.,'cat')]"; // 2 6
// Get all elements that contain the string cat, ignoring case
xpath = "//*[contains(translate(.,'abcdefghijklmnopqrstuvwxyz',"
+ " 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'),'CAT')]";
// 1 2 4 5 6 7
<?xml version="1.0" encoding="UTF-8"?>
<root id="1">
<elem1 id="2">cat</elem1>
<elem1 id="3"> dog </elem1>
<elem1 id="4">
cat
<elem2 id="5">
<elem3 id="6">cat</elem3>
</elem2>
dog
</elem1>
<elem1 id="7">Cat</elem1>
</root>
In IE 8 this method of using path is not working, why is that?