DOMNode::replaceChild

(PHP 5, PHP 7, PHP 8)

DOMNode::replaceChild — Bir çocuk düğümü yenisi ile değiştirir

Açıklama

public DOMNode::replaceChild(DOMNode $yeni, DOMNode $eski): DOMNode|false

Düğümün eski çocuk düğümünün yerine yeni düğümünü yerleştirir. Yeni düğüm zaten bir çocuk düğümse ikinci kez eklenmez. Yer değiştirme başarılı olursa eski düğüm döndürülür.

Bağımsız Değişkenler

yeni: Yeni düğüm. Hedef belgenin bir üyesi olmalıdır. Yani, DOMDocument->createXXX() yöntemlerinden biri ile oluşturulmuş veya DOMDocument::importNode() ile belgeye dahil edilmiş olmalıdır.
eski: Eski düğüm.

Dönen Değerler

Bir hata oluşursa false yoksa eski düğüm.

Hatalar/İstisnalar

DOM_NO_MODIFICATION_ALLOWED_ERR: Düğüm salt okunursa veya düğümün önceki ebeveyni salt okunur olarak yerleştirilmişse bu hata oluşur.
DOM_HIERARCHY_REQUEST_ERR: Düğüm, yeni düğümün türündeki çocuk düğümlere izin vermeyen türde ise veya yeni düğüm, çocuğu olacağı düğümün ebeveyni veya atalarından biri ise bu hata oluşur.
DOM_WRONG_DOCUMENT_ERR: Eğer yeni düğüm, çocuğu olacağı düğümü oluşturan belgeden farklı bir belge tarafından oluşturulmuşsa bu hata oluşur.
DOM_NOT_FOUND: eski düğüm, bir çocuk düğüm değilse bu hata oluşur.

Ayrıca Bakınız

DOMChildNode::replaceWith() - Replaces the node with new nodes
DOMNode::appendChild() - Listenin sonuna yeni bir çocuk ekler
DOMNode::removeChild() - Listeden belirtilen çocuğu siler

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User Contributed Notes 4 notes

down

jb at jbpros dot com ¶

19 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.

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aidan at php dot net ¶

19 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>

down

chealer at gmail dot com ¶

6 years ago


As of version 5.6, PHP still behaves as reported by jb at jbpros dot com. To use replaceChild() in a loop, the more standard pattern used in the following example can be used:

for ($currentNode = 0; $currentNode < $link->childNodes->length; $currentNode++) {
    $child = $link->childNodes[$currentNode];

    // "Remove" links, since links can't contain links
    if ($child instanceof DOMElement && $child->tagName == 'a') {
        $replacement = $dom->createTextNode($child->textContent);
        $link->replaceChild($replacement, $child);
    }
}

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franp at free dot fr ¶

20 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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