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DOMXPath::query


(PHP 5)

DOMXPath::query Evaluates the given XPath expression

Beschreibung

DOMNodeList DOMXPath::query ( string $expression [, DOMNode $contextnode ] )

Executes the given XPath expression .

Parameter-Liste

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.

Rückgabewerte

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

Beispiele

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$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"; }

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

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:

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$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"; }

Siehe auch

  • DOMXPath::evaluate - Evaluates the given XPath expression and returns a typed result if possible.