如何使用PHP DOMDocument删除属性？

Question

使用这段XML:

<my_xml>
  <entities>
    <image url="lalala.com/img.jpg" id="img1" />
    <image url="trololo.com/img.jpg" id="img2" />
  </entities>
</my_xml> 

我必须摆脱图像标签内的所有属性.所以,我做到了这一点:

<?php

$article = <<<XML
<my_xml>
  <entities>
    <image url="lalala.com/img.jpg" id="img1" />
    <image url="trololo.com/img.jpg" id="img2" />
  </entities>
</my_xml>  
XML;

$doc = new DOMDocument();
$doc->loadXML($article);
$dom_article = $doc->documentElement;
$entities = $dom_article->getElementsByTagName("entities");

foreach($entities->item(0)->childNodes as $child){ // get the image tags
  foreach($child->attributes as $att){ // get the attributes
    $child->removeAttributeNode($att); //remove the attribute
  }
}

?>

不知何故,当我尝试删除foreach块中的from属性时,它看起来像内部指针丢失,并且它不会删除这两个属性.

还有另一种方法吗？

提前致谢.

Answer 1

将内foreach循环更改为:

while ($child->hasAttributes())
  $child->removeAttributeNode($child->attributes->item(0));

或者回到前面删除:

if ($child->hasAttributes()) { 
  for ($i = $child->attributes->length - 1; $i >= 0; --$i)
    $child->removeAttributeNode($child->attributes->item($i));
}

或制作属性列表的副本:

if ($child->hasAttributes()) {
  foreach (iterator_to_array($child->attributes) as $attr)
    $child->removeAttributeNode($attr);
}

任何这些都可行.