ScotlandPHP 2016

DOMNode::C14N

(PHP 5 >= 5.2.0, PHP 7)

DOMNode::C14NCanonise des noeuds en une chaîne

Description

public string DOMNode::C14N ([ bool $exclusive [, bool $with_comments [, array $xpath [, array $ns_prefixes ]]]] )

Canonise des noeuds en une chaîne de caractères.

Liste de paramètres

exclusive

Active l'analyse des seuls noeuds correspondant à l'Xpath ou aux préfixes d'espace de noms fournis.

with_comments

Conserve les commentaires dans la sortie.

xpath

Un tableau de xpath utilisés pour filtrer les noeuds.

ns_prefixes

Un tableau de préfixes d'espaces de noms utilisés pour filtrer les noeuds.

Valeurs de retour

Retourne les noeuds canonisés, sous la forme d'une chaîne de caractères ou FALSE si une erreur survient

Voir aussi

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User Contributed Notes 3 notes

up
11
Rijk
3 years ago
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 );
up
4
jorda at edpsciences dot org
1 year ago
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>"
up
0
lordbaco
7 months ago
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!
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