DOMXPath
PHP Manual

DOMXPath::registerPhpFunctions

(PHP 5 >= 5.3.0)

DOMXPath::registerPhpFunctions — Register PHP functions as XPath functions

Descrierea

public void DOMXPath::registerPhpFunctions ([ mixed $restrict ] )

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

Parametri

restrict

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

This parameter can be either a string (a function name) or an array of function names.

Valorile întoarse

Nu este întoarsă nici o valoare.

Exemple

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";
}

?>

Exemplul de mai sus va afișa ceva similar cu:

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";
}

?>

Exemplul de mai sus va afișa ceva similar cu:

Books with multiple authors:
PHP Basics

Vedeți de asemenea

DOMXPath
PHP Manual