PHP 5.4.31 Released

DOMNode::replaceChild

(PHP 5)

DOMNode::replaceChild Remplace un fils

Description

public DOMNode DOMNode::replaceChild ( DOMNode $newnode , DOMNode $oldnode )

Cette fonction remplace le fils oldnode par le nouveau noeud spécifié. SI le nouveau noeud est déjà un fils, il ne sera pas ajouté une seconde fois. Si le remplacement réussi, l'ancien noeud sera retourné.

Liste de paramètres

newnode

Le nouveau noeud. Il doit être membre du document cible, i.e. créé par une des méthodes de DOMDocument->createXXX() ou importé dans le document par DOMDocument::importNode.

oldnode

L'ancien noeud.

Valeurs de retour

L'ancien noeud ou FALSE si une erreur survient.

Erreurs / Exceptions

DOM_NO_MODIFICATION_ALLOWED_ERR

Lancé si le noeud est en lecture seule ou si le parent précédent du noeud à insérer est en lecture seule.

DOM_HIERARCHY_REQUEST_ERR

Lancé si le noeud est d'un type qui n'autorise pas les fils du type du noeud newnode, ou si le noeud à insérer est un des ancêtres de ce noeud ou ce noeud lui-même.

DOM_WRONG_DOCUMENT_ERR

Émise si newnode a été créé depuis un document différent que celui qui a créé ce noeud.

DOM_NOT_FOUND

Lancé si oldnode n'est pas un fils de ce noeud.

Voir aussi

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User Contributed Notes 3 notes

up
1
jb at jbpros dot com
9 years ago
If you are trying to replace more than one node at once, you have to be careful about iterating over the DOMNodeList.  If the old node has a different name from the new node, it will be removed from the list once it has been replaced.  Use a regressive loop:

<?php

$xml
= new DOMDocument;
$xml->load('docfile.xml');

$elements = $xml->getElementsByTagNameNS('http://www.example.com/NS/', '*');
$i = $elements->length - 1;
while (
$i > -1) {
   
$element = $elements->item($i);
   
$ignore = false;

   
$newelement = $xml>createTextNode('Some new node!');
   
$element->parentNode->replaceChild($newelement, $element);
   
$i--;
}

?>

The loop counter ($i) will always be in the list's interval as removed elements indexes are above the counter.
up
1
aidan at php dot net
9 years ago
Here is a simple example for replacing a node:

Let's define our XML like so:

<?php
$xml
= <<<XML
<?xml version="1.0"?>
<root>
  <parent>
     <child>bar</child>
     <child>foo</child>
  </parent>
</root>
XML;
?>

If we wanted to replace the entire <parent> node, we could do something like this:

<?php
// Create a new document fragment to hold the new <parent> node
$parent = new DomDocument;
$parent_node = $parent ->createElement('parent');

// Add some children
$parent_node->appendChild($parent->createElement('child', 'somevalue'));
$parent_node->appendChild($parent->createElement('child', 'anothervalue'));

// Add the keywordset into the new document
// The $parent variable now holds the new node as a document fragment
$parent->appendChild($parent_node);
?>

Next, we need to locate the old node:

<?php
// Load the XML
$dom = new DomDocument;
$dom->loadXML($xml);

// Locate the old parent node
$xpath = new DOMXpath($dom);
$nodelist = $xpath->query('/root/parent');
$oldnode = $nodelist->item(0);
?>

We then import and replace the new node:

<?php
// Load the $parent document fragment into the current document
$newnode = $dom->importNode($parent->documentElement, true);

// Replace
$oldnode->parentNode->replaceChild($newnode, $oldnode);

// Display
echo $dom->saveXML();
?>

Our new node is successfully imported:

<?xml version="1.0"?>
<root>
<parent><child>somevalue</child><child>anothervalue</child></parent>
</root>
up
0
franp at free dot fr
9 years ago
1) If your XPath query returns a NodeList including a unique item, or if you know for sure the order of the items returned, you can use the "item(n)" syntax instead of the "foreach" syntax.
This can greatly improve you code lisibility.
s the method name implies, replaceChild cannot replace a node itself but a child of a node.
The trick is to use replaceChild on the parent node of your Xpath query result.

<?xml version="1.0" ?>
<action>
<actionGlobal>
  <actionGlobalFR>sometext</actionGlobalFR>
<actionGlobal>
</action>

$frag = $doc->createElement("actionGlobalFR");  
$fragA = $doc->createTextNode("anothertext");
$frag->appendChild($fragA);
     
$xpResult = $xp->query("/action/actionGlobal/actionGlobalFR");  
$blipblip = $xpResult->item(0)->parentNode->replaceChild($ajout, $xpResult->item(0));

2) Also, as the method name implies, replaceChild cannot replace a node itself but a child of a node.
Still it is possible to replace a node pointed by XPath istead of its child.
The trick is to use replaceChild on the parent node of your Xpath query result.

<?xml version="1.0" ?>
<action>
  <FR>French Text</FR>
</action>

<?php
$frag
= $doc->createElement("EN");  
$fragA = $doc->createTextNode("English Text");
$frag->appendChild($fragA);
     
$xpResult = $xp->query("/action/FR");  
$blipblip = $xpResult->item(0)->parentNode->replaceChild($fragA, $xpResult->item(0));
?>

Et voil� !

This produces :
<?xml version="1.0" ?>
<action>
  <EN>English Text</EN>
</action>

....................................................

3) Also, be carefull, you CANNOT replace a node that doesn't exist.
While this may seems obvious, it is easy to forget.

Consider this :
<?xml version="1.0" ?>
<action>
  <EN></EN>
</action>

You cannot use replaceChild() to turn this into :
<?xml version="1.0" ?>
<action>
  <EN>Some text</EN>
</action>

The reason is that since the <EN></EN> element is empty, it has no child (this is clearer to understand if you consider that <EN></EN> can be written <EN />).
The fact that you intend to put some text inbetween <EN> and </EN> does not change the fact that it has no text yet, thus no child yet.
When dealing with DOM, do not take your dream for the reality. The DOM parser doen't care about your dreams. If an element is currently empty, it has no child, whatever you intend to fill in.

Thus, the solution to teh problem is to use appendChild intead of replaceChild :

<?php
$fragA
= $doc->createTextNode("Some Text");
$xpResult = $xp->query("/action/EN");  
$blipblip = $xpResult->item(0)->appendChild($fragA);
?>

This produces the awaited :
<?xml version="1.0" ?>
<action>
  <EN>Some Text</EN>
</action>

....................................................

4) Note that the description of replaceChild in the doc is wrong. Arguments have been inverted.
The correct description is :
object DOMNode->replaceChild (object newnode, object oldnode)
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