PHP. Учебник. 2005

DOMXPath->query()

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DOMXPath->query()

(no version information, might be only in CVS)DOMXPath->query() -- Evaluates the given XPath expression

Описание

class DOMXPath {


DOMNodeList query ( string expression [, DOMNode contextnode] )


}

- Executes the given XPath expression.

Список параметров

-

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.

Возвращаемые значения

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

Примеры

-

Пример 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";
}
?>

Результат выполнения данного примера:
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";
}
?>

Смотрите также

-

DOMXPath->evaluate()

Пред.

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DOMXPath->evaluate()

Уровень выше

DOMXPath->registerNamespace() 22222

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