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DOMNodelist::item> <DOMNode::replaceChild
Last updated: Fri, 21 Nov 2008

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The DOMNodeList class

Class synopsis

DOMNodeList
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.

Table of Contents



DOMNodelist::item> <DOMNode::replaceChild
Last updated: Fri, 21 Nov 2008
 
add a note add a note User Contributed Notes
DOMNodeList
nascoedu
18-Sep-2008 03:44
Get some nodes from an existing xml file and add them to a new file:

<?php
$dom = new DOMDocument;
$dom->load($xmlsource);

/*create the xPath object _after_  loading the xml source, otherwise the query won't work:*/
$xPath = new DOMXPath($dom);

/*now get the nodes in a DOMNodeList:*/
$nodeList = $xPath->query($anXPathExpr);

/*create a new DOMDocument and add a root element:*/
$newDom = new DOMDocument('1.0','UTF-8');
$root = $newDom->createElement('root');
$root = $newDom->appendChild($root);

/* append all nodes from $nodeList to the new dom, as children of $root:*/
foreach ($nodeList as $domElement){
   $domNode = $newDom->importNode($domElement, true);
   $root->appendChild($domNode);
}
/*please note: importNode does not cast a DOMElement to a DOMNode!*/

/*save the new dom */
echo 'Wrote: ' . $newDom->save('newDOM.xml') . ' bytes';
?>

the following won't work and you'll end up with a DOMException: 'Wrong Document Error' (at least I did):

<?php
foreach ($nodeList as $element){
   $root->appendChild($element);
}
?>

Cheers! ;-)
---
WindowsXP, WAMP5 (appache 2.2.6), PHP 5.2.5, DOM/XML API Version 20031129, libxml 2.6.26
---
c dot 1 at smithies dot org
27-Aug-2008 03:26
I doubt the accuracy of what saad105050 wrote below. In particular, in his example, he seems to assume that $element->getElementsByTagName() will return NULL if there are no matching nodes. This is not what happens; as per the documentation, a DOMNodeList is returned with the length property zero.
bobvandell at hotmail dot com
26-Aug-2008 09:12
That's actually incorrect. You can use function results as objects. It makes building an API for your database very clean and neat. For example:

Our code:

$articles = Node::screate('tags', 123456)->assets('like:title:test')->articles;

We use the above code to get articles that are linked to assets that are linked to a specific tag in our database.
rohypnol
14-Jul-2008 12:28
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 10:10
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 03:14
$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 04:28
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 05:43
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 06:11
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 04:56
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 09:47
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 $node->nodeValue;
}
kassah at gmail dot com
04-May-2008 05:06
// Converts a DOMNodeList to an Array that can be easily foreached
function dnl2array($domnodelist) {
    $return = array();
    for ($i = 0; $i < $domnodelist->length; ++$i) {
        $return[] = $domnodelist->item($i);
    }
    return $return;
}
brack at wjp dot de
21-Apr-2008 02:35
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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DOMNodelist::item> <DOMNode::replaceChild
Last updated: Fri, 21 Nov 2008
 
 
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