Last updated: Fri, 20 Nov 2009

DOMNode::removeChild

(PHP 5)

DOMNode::removeChild — Removes child from list of children

Description

DOMNode DOMNode::removeChild ( DOMNode $oldnode )

This functions removes a child from a list of children.

Parameters

oldnode: The removed child.

Return Values

If the child could be removed the functions returns the old child.

Errors/Exceptions

DOM_NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
DOM_NOT_FOUND: Raised if oldnode is not a child of this node.

Examples

The following example will delete the chapter element of our XML document.

Example #1 Removing a child


<?php

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

$book = $doc->documentElement;

// we retrieve the chapter and remove it from the book
$chapter = $book->getElementsByTagName('chapter')->item(0);
$oldchapter = $book->removeChild($chapter);

echo $doc->saveXML();
?>

The above example will output:

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" 
          "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
<book id="listing">
 <title>My lists</title>
 
</book>


You can't remove DOMNodes from a DOMNodeList as you're iterating over them in a foreach loop. For example...





<?php


$domNodeList = $domDocument->getElementsByTagname('p');


foreach ( $domNodeList as $domElement ) {


  //  ...do stuff with $domElement...


  $domElement->parentNode->removeChild($domElement);


}


?>





... will seemingly leave the internal iterator on the foreach out of wack and results will be quite strange. Though, making a queue of items to remove seems to work. For example...





<?php


$domNodeList = $domDocument->getElementsByTagname('p');


$domElemsToRemove = array();


foreach ( $domNodeList as $domElement ) {


  // ...do stuff with $domElement...


  $domElemsToRemove[] = $domElement;


}


foreach( $domElemsToRemove as $domElement ){


  $domElement->parentNode->removeChild($domElement);


}


?>

Justin Sheckler
30-Jan-2009 10:44


These two functions might be helpful to anyone trying to delete a node and all of its children:





<?php


function deleteNode($node) {


    deleteChildren($node);


    $parent = $node->parentNode;


    $oldnode = $parent->removeChild($node);


}





function deleteChildren($node) {


    while (isset($node->firstChild)) {


        deleteChildren($node->firstChild);


        $node->removeChild($node->firstChild);


    }


}


?>

tim cameron ryan
19-Jul-2008 03:00


Or something like:



<?php



while ($node->childNodes->length)

     $node->removeChild($node->firstChild);



?>

Michael D (DigitalGemstones.com)
05-Jul-2008 06:15


Note that iterating through the childNodes array and removing those children will stop the iteration.



For example:

foreach($node->childNodes as $child)

{

  if(iWantToDeleteThisNode($child))

     $child->parentNode->removeChild($child);

}



Will not work.  Note that in removing the node, the childNodes array gets rebuilt (it seems) and so only the first item will be removed.  In order to properly remove all the children you want to remove, you will need to do something like the following:



$nodesToDelete = array();

foreach($node->childNodes as $child)

{

  if(iWantToDeleteThisNode($child))

    $nodesToDelete[] = $child;

}

foreach($nodesToDelete as $node)

{

  $node->parentNode->removeChild($node);

}



I believe this is actually more efficient than the first snippet would be (if it worked) but obviously I cannot benchmark it.

Wala
04-Apr-2008 12:57


I used the following to delete an entire node using the child element:



<?php

$childElement->parentNode->parentNode-> removeChild($childElement->parentNode);

?>



I could not have thought of it without the help of everyone who contributed to this thread.



Thanks!



(I had to introduce the extra space between parentNode->removeChild to get rid of the wordwrap() warning while posting this note)

Vasil Rangelov
06-Oct-2007 12:14


At the time of writing, I suppose rightfully, removeChild() removes only the selected node, but when you remove an element, it's child elements are not removed. If you want to achieve that, replaceChild() is the solution.



The following should remove all descendants of the $node DOMNode, regardless of it's name:

<?php

$node->replaceChild(new DOMElement($node->nodeName), $node);

?>

If you're replacing the root element, you must explicitly state that with $node->documentElement as the second argument.

lsoethout at hotmail dot com
11-Mar-2007 11:08


The previous example is not correct; it only works when the tags are direct childs of the top-level node.

Better is:



while($elem = $dom->getElementsByTagName("name")->item(0)) {

   $elem->parentNode->removeChild($elem);

}

dave at dgx dot cz
27-Aug-2006 08:10


remove all children of a given node (simple way):



$node->nodeValue = '';

mytto at openxtrem dot com
07-Sep-2005 04:20


Back again on removing childs and iterators robustness. 



Things get a bit more complicated when you only want to remove 'some' nodes according to a certain condition. Then you can't just remove the first one repeatedly.



The trick is to copy the content of the node list into a more robust collection than DOMNodeList, I name array!



The following piece of code will, for instance, remove all empty child nodes:



<?php

// Copy childNodes array

$childNodes = array();

foreach($node->childNodes as $childNode) {

  $childNodes[] = $childNode;

}



// Browse with the copy     

foreach ($childNodes as $childNode) {

  if (!$childNode->hasChildNodes()); {

    $childNode->parentNode->removeChild($childNode);

  }

}

?>

karan
28-Aug-2005 04:48


can we directly remove a node which has some children or do we need to remove the children first.



 while($mytn->hasChildNodes()) 

    {

     $mytn->removeChild($mytn->childNodes->item(0));

    }



echo $j;//this shows correct no of children



echo $mytn->childNodes->length;//after removing it 

                                         // shows 0..correct

    

$dom->save(net.xml);



but the changes r not reflected in the xml file

blaine (at) blainegarrett (dot com)
23-Aug-2005 12:10


This might be obvious, but might help someone as well...



If you simply have a node that you need to remove (perhaps from an xpath) and don't know the parent node offhand (the examples seem to assume you have the parent in a variable), then you can do something easy like this...



$node->parentNode->removeChild($node);



parentNode is a scalar property of the Element.



Hope that helps.



--

Blaine Garrett

Executive Director of the Art Attack

http://theartattack.org

pedro at leb dot usp dot br
30-May-2005 06:24


You may also use the hasChild function:

<?php



while($node->hasChildNodes()) {

  $node->removeChild($node->childNodes->item(0));

}



?>



When you remove a childNode, the next node becomes the first one!

vsematika at centrum dot cz
13-Feb-2005 05:35


For those who don't understand >sbeam at onsetcorps dot net on 02-Feb-2005 12:07< 'hack', here's a little discussion:





First but *wrong* try would be:


<?php


foreach ($parent->childNodes as $child) {


   $parent->removeChild($child);


?>


This doesn't work because DOM tree id modified on-the-fly and this confuses foreach loop.





The idea behind sbeam's trick is that after removing the first item in the first iteration, the second item in childNodes nodelist immediately becomes the first item. That's why we must _always_ remove the first child. Here's another implementation:





<?php


$count = $parent->childNodes->length;


for ($i = 0; $i < $count; $i++) {


   $oldNode = $parent->removeChild($parent->childNodes->item(0)); // !!! not item($i) !!!


}


?>

sbeam at onsetcorps dot net
02-Feb-2005 11:07


remove all children of a given node:

        

while ($parent->childNodes->length) {

      $parent->removeChild($parent->childNodes->item(0));

}

add a note

DOMNode::replaceChild

DOMNode::normalize