DOMXPath::query

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DOMXPath::query — Evaluates the given XPath expression

Description

DOMNodeList DOMXPath::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";

}

?>

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";

}

?>

DOMXPath::query

Description

Parameters

Return Values

Examples

See Also