DOMXPath->query()
(no version information, might be only in CVS)
DOMXPath->query() --
Evaluates the given XPath expression
Description
class
DOMXPath {
DOMNodeList
query ( string expression [, DOMNode contextnode] )
}
Executes the given XPath expression.
Parameters
expression
The XPath expression to execute.
contextnode
The optional contextnode can be specified for
doing relative XPath queries. By default, the queries are relative to
the root element.
Return Values
Returns a DOMNodeList containing all nodes matching
the given XPath expression. Any expression which do
not return nodes will return an empty DOMNodeList.
Examples
Example 1. Getting all the english books
<?php
$doc = new DOMDocument;
// We don't want to bother with white spaces
$doc->preserveWhiteSpace = false;
$doc->Load('book.xml');
$xpath = new DOMXPath($doc);
// We starts from the root element
$query = '//book/chapter/para/informaltable/tgroup/tbody/row/entry[. = "en"]';
$entries = $xpath->query($query);
foreach ($entries as $entry) {
echo "Found {$entry->previousSibling->previousSibling->nodeValue}," .
" by {$entry->previousSibling->nodeValue}\n";
}
?>
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The above example will output: Found The Grapes of Wrath, by John Steinbeck
Found The Pearl, by John Steinbeck |
We can also use the contextnode parameter to shorten
our expression:
<?php
$doc = new DOMDocument;
$doc->preserveWhiteSpace = false;
$doc->load('book.xml');
$xpath = new DOMXPath($doc);
$tbody = $doc->getElementsByTagName('tbody')->item(0);
// our query is relative to the tbody node
$query = 'row/entry[. = "en"]';
$entries = $xpath->query($query, $tbody);
foreach ($entries as $entry) {
echo "Found {$entry->previousSibling->previousSibling->nodeValue}," .
" by {$entry->previousSibling->nodeValue}\n";
}
?>
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