DOMXPath::registerPhpFunctionNS

(PHP >= 8.4.0)

DOMXPath::registerPhpFunctionNSRegister a PHP functions as namespaced XPath function

Descrizione

public DOMXPath::registerPhpFunctionNS(string $namespaceURI, string $name, callable $callable): void

This method enables the ability to use a PHP function as a namespaced XPath function inside XPath expressions.

Elenco dei parametri

namespaceURI
The URI of the namespace.
name
The local function name inside the namespace.
callable
The PHP function to call when the XPath function gets called within the XPath expression. When a node list is passed as parameter to the callback, they are arrays containing the matched DOM nodes.

Valori restituiti

Nessun valore viene restituito.

Esempi

Example #1 Register a namespaced XPath function and call it from the XPath expression

<?php
$xml
= <<<EOB
<books>
<book>
<title>PHP Basics</title>
<author>Jim Smith</author>
<author>Jane Smith</author>
</book>
<book>
<title>PHP Secrets</title>
<author>Jenny Smythe</author>
</book>
<book>
<title>XML basics</title>
<author>Joe Black</author>
</book>
</books>
EOB;

$doc = new DOMDocument;
$doc->loadXML($xml);

$xpath = new DOMXPath($doc);

// Register the my: namespace (required)
$xpath->registerNamespace("my", "urn:my.ns");

// Register PHP functions (no restrictions)
$xpath->registerPHPFunctionNS(
'urn:my.ns',
'substring',
fn (array
$arg1, int $start, int $length) => substr($arg1[0]->textContent, $start, $length)
);

// Call substr function on the book title
$nodes = $xpath->query('//book[my:substring(title, 0, 3) = "PHP"]');

echo
"Found {$nodes->length} books starting with 'PHP':\n";
foreach (
$nodes as $node) {
$title = $node->getElementsByTagName("title")->item(0)->nodeValue;
$author = $node->getElementsByTagName("author")->item(0)->nodeValue;
echo
"$title by $author\n";
}

?>

Il precedente esempio visualizzerà qualcosa simile a:

Found 2 books starting with 'PHP':
PHP Basics by Jim Smith
PHP Secrets by Jenny Smythe

Vedere anche:

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