SunshinePHP Developer Conference 2015

The DOMNodeList class

(PHP 5)

Sinopsisul clasei

DOMNodeList implements Traversable {
/* Proprietăți */
readonly public int $length ;
/* Metode */
DOMNode DOMNodelist::item ( int $index )
}

Proprietăți

length

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

Vedeți de asemenea

Cuprins

add a note add a note

User Contributed Notes 10 notes

up
5
ignitedfirestarter at gmail dot com
2 years ago
If you want to recurse over a DOM then this might help:
<?php

/**
* PHP's DOM classes are recursive but don't provide an implementation of
* RecursiveIterator. This class provides a RecursiveIterator for looping over DOMNodeList
*/
class DOMNodeRecursiveIterator extends ArrayIterator implements RecursiveIterator {
 
  public function
__construct (DOMNodeList $node_list) {
   
   
$nodes = array();
    foreach(
$node_list as $node) {
     
$nodes[] = $node;
    }
   
   
parent::__construct($nodes);
   
  }
 
  public function
getRecursiveIterator(){
    return new
RecursiveIteratorIterator($this, RecursiveIteratorIterator::SELF_FIRST);
  }
 
  public function
hasChildren () {
    return
$this->current()->hasChildNodes();
  }

 
  public function
getChildren () {
    return new
self($this->current()->childNodes);
  }
 
}
?>
up
2
james dot j dot hackett at gmail dot com
6 years ago
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;
}
up
2
geompse at gmail dot com
4 years ago
Note that $length is calculated (php5.3.2).
Iterating over a large NodeList may be time expensive.

Prefer :
$nb = $nodelist->length;
for($pos=0; $pos<$nb; $pos++)

Than:
for($pos=0; $pos<$nodelist->length; $pos++)

I had a hard time figuring that out...
up
2
drichter at muvicom dot de
6 years ago
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() :)
up
2
brack at wjp dot de
6 years ago
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.
up
0
c dot 1 at smithies dot org
6 years ago
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.
up
0
bobvandell at hotmail dot com
6 years ago
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.
up
0
c dot 1 at smithies dot org
6 years ago
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;
  }
}
up
-1
drichter at muvicom dot de
6 years ago
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 ...)
up
-2
kassah at gmail dot com
6 years ago
// 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;
}
To Top