(PHP 5 >= 5.3.0, PHP 7, PHP 8)
DOMXPath::registerPhpFunctions — Register PHP functions as XPath functions
This method enables the ability to use PHP functions within XPath expressions.
Es wird kein Wert zurückgegeben.
The following examples use book.xml which contains the following:
Beispiel #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>
Beispiel #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";
}
?>Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:
Found 2 books starting with 'PHP': PHP Basics by Jim Smith PHP Secrets by Jenny Smythe
Beispiel #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";
}
?>Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:
Books with multiple authors: PHP Basics