The DOMNodeList class

Class synopsis

DOMNodeList

class DOMNodeList {

/* Properties */

readonly public int $length ;

/* Methods */

DOMNode DOMNodelist::item ( int $index )

}

Properties

length: The number of nodes in the list. The range of valid child node indices is 0 to length - 1 inclusive.

DOMNodelist::item — Retrieves a node specified by index

DOMNodelist::item

DOMNode::replaceChild

Last updated: Fri, 18 Jul 2008

add a note User Contributed Notes
DOMNodeList

rohypnol
14-Jul-2008 08:28


That's simply because up to and including PHP 5 (latest version at this time) you can't use a function result as an object even if it is an object.



Work:

1) $obj->sub_obj->method();

2) $sub_obj = $obj->get_sub_obj();

   $sub_obj->method();



Don't work:

1) $obj->get_sub_obj()->method();

2) echo $obj->get_sub_obj()->property;

saad0105050 at gmail dot com
06-Jul-2008 06:10


Problem with accessing return value of DOMNodeList::item() method.



When using the following code segment:

---------------------



$messageNodes = $doc->getElementsByTagName( "message" );

if( $messageNodes != NULL )

{

     $messageStr = $messageNodes->item( 0 )->firstChild->nodeValue;

}

---------------------

PHP gives an error: "syntax error, unexpected T_OBJECT_OPERATOR"



But if I modify it like the following:

---------------------

$messageNodes = $doc->getElementsByTagName( "message" );

if( $messageNodes != NULL )

{

    $messageNode = $messageNodes->item( 0 );

    $messageStr =  messageNode->firstChild->nodeValue;

}

---------------------

There is no error.



I guess, the return element of DOMNodeList::item() function can not be readily accessed via "->" operator.

mark at codedesigner dot nl
05-Jun-2008 11:14


$newNode = $dom->createElement('newNode') ;

foreach ($nodeList as $node) {

  echo $node->nodeValue ;

  $newNode->appendChild($node) ;

}



the problem lies with the fact that foreach works on a copy of your object. The solution is simple, add & to $node



$newNode = $dom->createElement('newNode') ;

foreach ($nodeList as &$node) {

  echo $node->nodeValue ;

  $newNode->appendChild($node) ;

}

a dot buffa at sns dot it
29-May-2008 12:28


I agree with drichter at muvicom dot de.



For istance, in order to delete each child node of a particular parent node, 

<?php

               

while ($parentNode->hasChildNodes()){

  $domNodeList = $parentNode->childNodes;

  $parentNode->removeChild($domNodeList->item(0));

}



?>



In other word you have to uptade the DomNodeList on every iteration.



In my opinion, the DomNodeList class is useless.

c dot 1 at smithies dot org
23-May-2008 01:43


You can modify, and even delete, nodes from a DOMNodeList if you iterate backwards:



$els = $document->getElementsByTagName('input');

for ($i = $els->length; --$i >= 0; ) {

  $el = $els->item($i);

  switch ($el->getAttribute('name')) {

    case 'MAX_FILE_SIZE' :

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

    break;

    case 'inputfile' :

      $el->setAttribute('type', 'text');

    //break;

  }

}

drichter at muvicom dot de
14-May-2008 02:11


Addition to my first note:



An traditional for-loop does not allow you to change the DOM-tree while looping - the effects are the nearly the same as with foreach. So you have to collect the nodes in an array and do the tree-altering stuff within a second loop (looping the array this time ...)

drichter at muvicom dot de
14-May-2008 12:56


I have done some testing and have found 2 results:

(My System: Win XP with PHP 5.2.1)



1) Iteration with foreach does function correctly as "james dot j dot hackett at gmail dot com" writes, _if_ you only do readonly stuff with foreach or minor writings of some attributes.



2) foreach does not function, if you are doing some DOM-Operations while iterating. In my situation it was adding the iterated $node as an child to an new node:



$newNode = $dom->createElement('newNode') ;

foreach ($nodeList as $node) {

  echo $node->nodeValue ;

  $newNode->appendChild($node) ;

}



This only gives you the first element ...



I'm interpreting it as an confusing but correct behavior because of the changes within the $dom-object while appending the node at an additional place ... 



So, if you want to do something like 2) use for, length and item() :)

james dot j dot hackett at gmail dot com
08-May-2008 05:47


In Response to 'kassah at gmail'



You don't need to convert a DOMNodeList to an array in order iterate through it using 'foreach'.  You can use foreach directly with the DOMNodeList.



$nodeList = $someDomDocument->getElementsbytagname('user');



foreach ($nodeList as $node) {

    echo $node->nodeValue;

}

kassah at gmail dot com
05-May-2008 01:06


// Converts a DOMNodeList to an Array that can be easily foreached

function dnl2array($domnodelist) {

    $return = array();

    for ($i = 0; $i < $domnodelist->length; ++$i) {

        $return[] = $domnodelist->item($i);

    }

    return $return;

}

brack at wjp dot de
21-Apr-2008 10:35


In PHP 5.2.5 (Windows) it is not possible to iterate correctly over the DOMNodeList object returned by DOMNode->childNodes using foreach. Instead I had to use the for loop in conjunction with the item() method of DOMNodeList for iterating over all child nodes correctly.



I don't know whether this is really a bug, but apparently it is.

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