Podręcznik PHP
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DOMXPath->query()

DOMXPath->query() --  Evaluates the given XPath expression

Opis

class DOMXPath {

DOMNodeList query ( string expression [, DOMNode contextnode] )

}

Executes the given XPath expression.

Parametry

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.

Zwracane wartości

Returns a DOMNodeList containing all nodes matching the given XPath expression. Any expression which do not return nodes will return an empty DOMNodeList.

Przykłady

Przykład 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";
}
?>

Powyższy przykład wyświetli:

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";
}
?>

Patrz także

DOMXPath->evaluate()

PoprzedniSpis treściNastępny
DOMXPath->evaluate()Początek rozdziałuDOMXPath->registerNamespace()

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Generated: 2007-01-26 18:02:43