我有这个结构:
<p>Second paragraph</p>
<p>First paragraph</p>
<p>Third paragraph</p>
我想用PHP DOM重新排列元素,把它变成这样的东西:
<p>First paragraph</p>
<p>Second paragraph</p>
<p>Third paragraph</p>
我尝试使用以下代码执行此操作:
$html = "<p>Second paragraph</p><p>First paragraph</p><p>Third paragraph</p>";
$dom = new domDocument;
$dom->loadHTML( $html );
$dom->getElementsByTagName('p')->item(1)->insertBefore($dom->getElementsByTagName('p')->item(0));
但是当我使用时:
echo $dom->getElementsByTagName('p')->item(0)->nodeValue;
我明白了:
First paragraphSecond paragraph
结果,所以我想我在这里做错了.
来自PHP 文档：
public DOMNode DOMNode::insertBefore ( DOMNode $newnode [, DOMNode $refnode ] )
refnode
The reference node. If not supplied, newnode is appended to the children.
因此，由于您没有指定引用节点，因此它会将其附加到子节点。您的代码将生成以下 HTML：
<html>
<body>
<p>First paragraph<p>Second paragraph</p></p>
<p>Third paragraph</p>
</body>
</html>
您需要做的是参考insertBefore第二段parentNode，如下所示：
$nodes = $dom->getElementsByTagName('p');
$nodes->item(0)->parentNode->insertBefore($nodes->item(1), $nodes->item(0));
echo $dom->saveHTML();
输出：
<html>
<body>
<p>First paragraph</p>
<p>Second paragraph</p>
<p>Third paragraph</p>
</body>
</html>