DOMXPath
PHP Manual

DOMXPath::registerPhpFunctions

(PHP 5 >= 5.3.0)

DOMXPath::registerPhpFunctionsRegister PHP functions as XPath functions

説明

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

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

パラメータ

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.

返り値

値を返しません。

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

例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>

例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";
}

?>

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

例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";
}

?>

上の例の出力は、 たとえば以下のようになります。

Books with multiple authors:
PHP Basics

参考


DOMXPath
PHP Manual