(PHP 5 >= 5.2.0, PHP 7, PHP 8)
DOMNode::C14N — Канонизировать узлы в строку
$exclusive = false,$withComments = false,$xpath = null,$nsPrefixes = nullКанонизировать узлы в строку
exclusiveВключить эксклюзивный разбор только тех узлов, которые совпадают с предоставленными xpath или ns_prefixes.
withCommentsСохранять комментарии в выводе.
xpath
Массив xpath для фильтрации узлов.
nsPrefixesМассив префиксов пространств имён для фильтрации узлов.
Возвращает канонизированные узлы в виде строки или false в случае возникновения ошибки
When working with (malformed) HTML, you're probably better off using DOMDocument's saveHTML() method instead. C14N() will attempt to make your HTML valid XML, for example by converting <br> to <br></br>.
So instead of:
$html = $Node->C14N();
Use:
$html = $Node->ownerDocument->saveHTML( $Node );
C14N() returns an empty string if the node is not included in the document tree:
<?php
$d = new DOMDocument('1.0');
$d->loadXML('<foo></foo>');
$n = $d->createElement('bar');
var_dump($n->C14N());
$d->documentElement->appendChild($n);
var_dump($n->C14N());
?>
output:
string(0) ""
string(11) "<bar></bar>"
Good to know:
<< Due to a known issue in XML canonicalization in PHP, processing large metadata files in SimpleSAMLphp takes a big amount of resources, with that amount growing approximately by the square of the number of entities in the metadata set >>
https://simplesamlphp.org/metaprocessing
<< The C14N() function appears to have a runtime that is O(N^2) (or possibly worse?) depending on input size, which means that it becomes very slow as the input grows. For example, an input with around 196000 nodes takes about 290 seconds, while an input with 486000 nodes takes 2200 seconds. >>
https://bugs.php.net/bug.php?id=53655
We had the same issue with a 4.1 MB XML (105k lines). The sample code of ticket #53655 takes 1h36 minute to canonicalize it!
