DOMXPath::registerPhpFunctions

    (PHP 5 >= 5.3.0, PHP 7, PHP 8)

    DOMXPath::registerPhpFunctions — Register PHP functions as XPath functions

    Опис

    public DOMXPath::registerPhpFunctions(string|array|null $restrict = null): void

    This method enables the ability to use PHP functions within XPath expressions.

    Параметри

    restrict

    Use this parameter to only allow certain functions to be called from XPath.

    This parameter can be one of the following: a string (a function name), an indexed array of function names, or an associative array with keys being the function name and the associated value being the callable.

    Значення, що повертаються

    Не повертає значень.

    Помилки/виключення

    • Throws a ValueError if a callback name is not valid.
    • Throws a ValueError if options contains an invalid option.
    • Throws a ValueError if overrideEncoding is an unknown encoding.
    • Throws a TypeError if a given callback is not callable.

    Журнал змін

    Версія Опис
    8.4.0 Invalid callback names now throws a ValueError. Passing a non-callable entry now throws a TypeError.
    8.4.0 It is now possible to use callables for callbacks when using restrict with array entries.

    Приклади

    The following examples use book.xml which contains the following:

    Приклад #1 book.xml

    <?xml version="1.0" encoding="UTF-8"?>
<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>

    Приклад #2 DOMXPath::registerPhpFunctions() with php:functionString

    <?php
    $doc     = new DOMDocument;
    $doc->load('examples/book-simple.xml');

    $xpath = new DOMXPath($doc);

    // Register the php: namespace (required)
    $xpath->registerNamespace("php", "http://php.net/xpath");

    // Register PHP functions (no restrictions)
    $xpath->registerPhpFunctions();

    // Call substr function on the book title
    $nodes = $xpath->query('//book[php:functionString("substr", 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";
    }

    ?>

    Поданий вище приклад виведе щось схоже на:

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

    Приклад #3 DOMXPath::registerPhpFunctions() with php:function

    <?php
    $doc     = new DOMDocument;
    $doc->load('examples/book-simple.xml');

    $xpath = new DOMXPath($doc);

    // Register the php: namespace (required)
    $xpath->registerNamespace("php", "http://php.net/xpath");

    // Register PHP functions (has_multiple only)
    $xpath->registerPhpFunctions("has_multiple");

    function     has_multiple($nodes) {
    // Return true if more than one author
    return count($nodes) > 1;
    }
    // Filter books with multiple authors
    $books = $xpath->query('//book[php:function("has_multiple", author)]');

    echo     "Books with multiple authors:\n";
    foreach (    $books as $book) {
    echo     $book->getElementsByTagName("title")->item(0)->nodeValue . "\n";
    }

    ?>

    Поданий вище приклад виведе щось схоже на:

    Books with multiple authors:
PHP Basics

    Приклад #4 DOMXPath::registerPhpFunctions() with a callable

    <?php
    $doc     = new DOMDocument;
    $doc->load('examples/book-simple.xml');

    $xpath = new DOMXPath($doc);

    // Register the php: namespace (required)
    $xpath->registerNamespace("php", "http://php.net/xpath");

    // Register PHP functions (has_multiple only)
    $xpath->registerPhpFunctions(["has_multiple" => fn ($nodes) => count($nodes) > 1]);

    // Filter books with multiple authors
    $books = $xpath->query('//book[php:function("has_multiple", author)]');

    echo     "Books with multiple authors:\n";
    foreach (    $books as $book) {
    echo     $book->getElementsByTagName("title")->item(0)->nodeValue . "\n";
    }

    ?>

    Поданий вище приклад виведе щось схоже на:

    Books with multiple authors:
PHP Basics

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