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PHP - Manual: DOMNamedNodeMap

2024-11-13

The DOMNamedNodeMap class

(PHP 5, PHP 7, PHP 8)

类摘要

class DOMNamedNodeMap implements IteratorAggregate, Countable {
/* 属性 */
public readonly int $length;
/* 方法 */
public count(): int
public getNamedItem(string $qualifiedName): ?DOMNode
public getNamedItemNS(?string $namespace, string $localName): ?DOMNode
public item(int $index): ?DOMNode
}

属性

length

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

更新日志

版本 说明
8.0.0 The unimplemented methods DOMNamedNodeMap::setNamedItem(), DOMNamedNodeMap::removeNamedItem(), DOMNamedNodeMap::setNamedItemNS() and DOMNamedNodeMap::removeNamedItem() have been removed.
8.0.0 DOMNamedNodeMap implements IteratorAggregate now. Previously, Traversable was implemented instead.

目录

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User Contributed Notes 3 notes

up
6
kendsnyder at gmail dot com
12 years ago
To add to xafford's comment. When iterating a named node map collection using ->item() or using foreach, removing a attribute with DOMNode->removeAttribute() or DOMNode->removeAttributeNode() alters the collection as if it were a stack. To illustrate, the code below tries to remove all attributes from each element but only removes the first. One work around is to copy the named node map into an array before removing attributes. Using PHP 5.2.9 on Windows XP.

<?php
error_reporting
(E_ALL);
$html  = '<h1 id="h1test" class="h1test">Heading</h1>';
$html .= '<p align="left" class="ptest">Hello World</p>';

$doc = new DOMDocument();
$doc->loadHTML($html);

// remove attributes from  the h1 element
$h1 = $doc->getElementsByTagName('h1')->item(0);
$length = $h1->attributes->length;
for (
$i = 0; $i < $length; ++$i) {
   
$name = $h1->attributes->item($i)->name;
   
$h1->removeAttribute($name);
    echo
"h1: removed attribute `$name`<br>";
}
// remove attributes from the p element
$p = $doc->getElementsByTagName('p')->item(0);
foreach (
$p->attributes as $name => $attrNode) {
   
$p->removeAttribute($name);
    echo
"p: removed attribute `$name`<br>";
}

?>

OUTPUT:
-------
h1: removed attribute `id`

Notice: Trying to get property of non-object in nodemap.php on line 13
h1: removed attribute ``
p: removed attribute `align`
up
3
xafford
12 years ago
I stumbled upon a problem with DOMNamedNodeMap. If you iterate over a DOMNamedNodeMap, representing the attributes of a DOMElement with foreach and you use DOMElement::removeAttributeNode only the first attribute will be handled.

Example (not complete):

<?php

/*
* Imagine you got a node like this:
* <a onclick="alert('evil')" href="http://example.com">evil</a>
* and onclick should be removed, href would not be tested.
*/

foreach ( $node->attributes as $attribute )
{

    echo
'checking attribute ', $attribute->name, '<br />';

    if ( !
in_array ( $attribute->name, $allowed_attributes ) )
    {
       
$node->removeAttributeNode ( $attribute );
    }

}

?>

The output would be:

checking attribute onclick
up
1
sirajshaikh96 at yahoo dot com
1 year ago
I have tried to solve the general problem occurs in DOMNamedNodeMap that during executing for/foreachloop after executing removeAttribute('$name') for item(0), item(1) is not executing and warning occurs. Following codes give the solution of this problem that in loop item(0) should be applied rather than item($i) because after removing first attribute node now present element has only one attribute node.

<?php
$html 
= '<h1 id="h1test" class="h2test">Heading</h1>';
$html .= '<p align="left" class="right">Hello World</p>';

$doc = new DOMDocument();
$doc->loadHTML($html);

// remove attributes from  the h1 element
$h1 = $doc->getElementsByTagName('h1')->item(0);
$length = $h1->attributes->length;
for (
$i = 0; $i < $length; $i++) {   
   
$name = $h1->attributes->item(0)->nodeName;
   
$value = $h1->attributes->item(0)->nodeValue;
   
$h1->removeAttribute($name);   
    echo
"h1: removed attribute name :- " .$name."</br>";
    echo
"h1: removed attribute value :- " .$value."</br>";  
    }
// remove attributes from the p element
$p = $doc->getElementsByTagName('p')->item(0);
for (
$i = 0; $i < $length; $i++) {       
   
$name = $p->attributes->item(0)->nodeName;
   
$value = $p->attributes->item(0)->nodeValue;
   
$p->removeAttribute($name);   
    echo
"p: removed attribute name :- " .$name."</br>";
    echo
"p: removed attribute value :- " .$value."</br>";  
}
?>

OUTPUT:

h1: removed attribute name :- id
h1: removed attribute value :- h1test
h1: removed attribute name :- class
h1: removed attribute value :- h2test
p: removed attribute name :- align
p: removed attribute value :- left
p: removed attribute name :- class
p: removed attribute value :- right

官方地址:https://www.php.net/manual/en/class.domnamednodemap.php

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