PHP 5.6.0 released

DOMNodelist::item

(PHP 5)

DOMNodelist::item インデックスで指定したノードを取得する

説明

DOMNode DOMNodelist::item ( int $index )

DOMNodeList オブジェクトから、 index で指定したノードを取得します。

ヒント

コレクション内のノードの数を知るには、 DOMNodeList オブジェクトの length プロパティを使用します。

パラメータ

index

コレクション内のノードのインデックス。

返り値

DOMNodeList 内の index 番目の位置にあるノード、あるいはインデックスが不正な形式の場合は NULL を返します。

例1 テーブル内のすべての要素を取得する

<?php

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

$items $doc->getElementsByTagName('entry');

for (
$i 0$i $items->length$i++) {
    echo 
$items->item($i)->nodeValue "\n";
}

?>

別の方法として foreach を使用することも可能で、 こちらのほうがずっと使いやすいでしょう。

<?php

foreach ($items as $item) {
    echo 
$item->nodeValue "\n";
}

?>

上の例の出力は以下となります。

Title
Author
Language
ISBN
The Grapes of Wrath
John Steinbeck
en
0140186409
The Pearl
John Steinbeck
en
014017737X
Samarcande
Amine Maalouf
fr
2253051209

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User Contributed Notes 9 notes

up
2
Anonymous
2 years ago
calling domnodelist->item($i) with an index $i greater than domnodelist->length - 1 , will return the entire document, will not produce an error, and will not circle back to the start of the list.
up
1
strangerli at onlinehome dot de
11 months ago
Actually "item" returns DOMElement and not DOMNode. DOMElement extends only DOMNode.

http://3v4l.org/KAj7c
up
1
olivier dot berger at it-sudparis dot eu
6 years ago
It seems that with zend.ze1_compatibility_mode on, the only way to iterate over the items list is with :
for ($i = 0; $i < $nodeList->length; ++$i) {
    $nodeName = $nodeList->item($i)->nodeName;
    $nodeValue = $nodeList->item($i)->nodeValue;
}

As other attemps failed :

for ($i = 0; $i < $nodeList->length; ++$i) {
    $node = &$nodeList->item($i);
    $nodeName = $node->nodeName;
    $nodeValue = $node->nodeValue;
}

or :
foreach ($nodeList as $node) {
    echo $node->nodeName;
    echo $node->nodeValue;
}
up
1
vinyanov at poczta dot onet dot pl
6 years ago
SimpleXML has its own SPL iterator. See http://www.php.net/~helly/php/ext/spl/classSimpleXMLIterator.html . But I guess that there are none for DOM nodes. By the way, two out of three implementations I found over the Net were not recursive, so I wrote my own. Here is the snippet:

<?php

class DOMNodeListIterator implements RecursiveIterator
{
    private
       
$nodes,
       
$offset;

    function
__construct(DOMNodeList $nodes)
    {
        return
$this -> nodes = $nodes;
    }
   
    function
rewind()
    {
        return
$this -> offset = 0;
    }
   
    function
current()
    {
        return
$this -> nodes -> item($this -> offset);
    }

    function
key()
    {
        return
$this -> current() -> nodeName;
    }
   
    function
next()
    {
        return
$this -> offset++;
    }
   
    function
valid()
    {
        return
$this -> offset < $this -> nodes -> length;
    }
   
    function
hasChildren()
    {
        return isset(
$this -> current() -> childNodes -> length) && $this -> current() -> childNodes -> length > 0;
    }
   
    function
getChildren()
    {
        return new
self($this -> current() -> childNodes);
    }
}

?>

Remember to use RecursiveIteratorIterator::SELF_FIRST flag when you create your iterator iterator.

<?php

$iterator
= new DOMNodeListIterator($document -> childNodes);
$iterator = new RecursiveIteratorIterator($iterator, RecursiveIteratorIterator::SELF_FIRST);

?>

Should work, has just few minutes though. :)
up
0
Nagy Attila
3 years ago
DOMNodeList::item does not return in constant time!

If you need to iterate over large nodelist then you'd better use standard navigation.

Instead of:

<?php
foreach ($nodelist as $node) {
   
// do something
}
?>

you could do:

<?php
$node
= $parentnode->firstChild;

do {
   
// do something
} while ($node = $node->nextSibling);
?>
up
0
Hayley Watson
6 years ago
Keep in mind that DOMNodelists are "live" - changes to the document or node that the DOMNodelist was derived from will be reflected in the DOMNodelist. In other words, a list of a parent node's children will change if you change the parent's children!
up
0
james dot dunmore at gmai dot com
7 years ago
tfg_allardyce at gmail dot com

I have had exactly this problem.

To rectify I've had to do this:
<?php
$old_element
= $doc->getElementsByTagName('Element1')->item(0);
$new_element = $doc->createElement('NewElement1');

$old_element_childNodes = $old_element->childNodes;
$length = $old_element_childNodes->length;

for(
$i = 0; $i < $length; $i++)
{       
   
$oldChildren_array[] = $old_element_childNodes->item($i);
}

foreach(
$oldChildren_array as $old_c)
{
   
$new_element->appendChild($old_c);
}
?>

Rather than this:
(which I will bug report)
<?php
$old_element
= $doc->getElementsByTagName('Element1')->item(0):
$new_element = $doc->createElement('NewElement1');

foreach(
$old_element->childNode as $node)
{
    
$new_element->appendChild($node);
}

?>

Using the latter, randomally removes the children!
up
0
Geoffrey Thubron
7 years ago
@ tfg_allardyce at gmail dot com

You could loop through the list backwards, that way, you are only ever taking off the last item from the list, and hence wont have disrupted the order.
up
0
oliver dot christen at camptocamp dot com
7 years ago
NodeList are something annoying because you can't output the content with a simple print_r, so I did a little function that add all the node to a new empty DOMDocument and output it as a string.
Have fun.

<?php

public function domNodeList_to_string($DomNodeList) {
   
$output = '';
   
$doc = new DOMDocument;
    while (
$node = $DomNodeList->item($i) ) {
       
// import node
       
$domNode = $doc->importNode($node, true);
       
// append node
       
$doc->appendChild($domNode);
       
$i++;
    }
   
$output = $doc->saveXML();
   
$output = print_r($output, 1);
   
// I added this because xml output and ajax do not like each others
   
$output = htmlspecialchars($output);
    return
$output;
}

?>
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