DOMXPath::registerPhpFunctionNS

    (PHP >= 8.4.0)

    DOMXPath::registerPhpFunctionNS — Register a PHP functions as namespaced XPath function

    説明

    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.

    パラメータ

    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.

    戻り値

    値を返しません。

    例

    例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";
    }

    ?>

    上の例の出力は、 たとえば以下のようになります。

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

    参考

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