DOMXPath->query()
(no version information, might be only in CVS)
DOMXPath->query() --
Evaluates the given XPath expression
Beschreibung
class
DOMXPath {
DOMNodeList
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
Beispiel 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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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:
<?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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