DOMXPath::registerPhpFunctions
(PHP 5 >= 5.3.0)
DOMXPath::registerPhpFunctions — Register PHP functions as XPath functions
Description
This method enables the ability to use PHP functions within XPath expressions.
Parameters
Return Values
No value is returned.
Examples
The following examples use book.xml which contains the following:
Example #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>
Example #2 DOMXPath::registerPHPFunctions() with php:functionString
<?php
$doc = new DOMDocument;
$doc->load('book.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";
}
?>
The above example will output something similar to:
Found 2 books starting with 'PHP': PHP Basics by Jim Smith PHP Secrets by Jenny Smythe
Example #3 DOMXPath::registerPHPFunctions() with php:function
<?php
$doc = new DOMDocument;
$doc->load('book.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";
}
?>
The above example will output something similar to:
Books with multiple authors: PHP Basics
See Also
- DOMXPath::registerNamespace() - Registers the namespace with the DOMXPath object
- DOMXPath::query() - Evaluates the given XPath expression
- DOMXPath::evaluate() - Evaluates the given XPath expression and returns a typed result if possible
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Обработка XML
- Document Object Model
- Функция DOMXPath::__construct() - Создает новый объект класса DOMXPath
- DOMXPath::evaluate
- Функция DOMXPath::query() - Выполняет заданное XPath выражение
- Функция DOMXPath::registerNamespace() - Ассоциирует пространство имен с объектом DOMXPath
- Функция DOMXPath::registerPhpFunctions() - Регистрация функций PHP как XPath функций
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