How can I use XPath and DOM to replace a node/element in php?
Say I have the following html
$html = '
<div class="website">
<div>
<div id="old_div">
<p>some text</p>
<p>some text</p>
<p>some text</p>
<p>some text</p>
<div class="a class">
<p>some text</p>
<p>some text</p>
</div>
</div>
<div id="another_div"></div>
</div>
</div>
';
And I want to replace #old_div with the following:
$replacement = '<div id="new_div">this is new</div>';
To give an end result of:
$html = '
<div class="website">
<div>
<div id="new_div">this is new</div>
<div id="another_div"></div>
</div>
</div>
';
Is there an easy cut-and-paste function for doing this with PHP?
Final working code thanks to all Gordon's help:
<?php
$html = <<< HTML
<div class="website">
<div>
<div id="old_div">
<p>some text</p>
<p>some text</p>
<p>some text</p>
<p>some text</p>
<div class="a class">
<p>some text</p>
<p>some text</p>
</div>
</div>
<div id="another_div"></div>
</div>
</div>
HTML;
$dom = new DOMDocument;
$dom->loadXml($html); // use loadHTML if it's invalid XHTML
//create replacement
$replacement = $dom->createDocumentFragment();
$replacement ->appendXML('<div id="new_div">this is new</div>');
//make replacement
$xp = new DOMXPath($dom);
$oldNode = $xp->query('//div[@id="old_div"]')->item(0);
$oldNode->parentNode->replaceChild($replacement , $oldNode);
//save html output
$new_html = $dom->saveXml($dom->documentElement);
echo $new_html;
?>
Since the answer in the linked duplicate is not that comprehensive, I'll give an example:
$dom = new DOMDocument;
$dom->loadXml($html); // use loadHTML if its invalid (X)HTML
// create the new element
$newNode = $dom->createElement('div', 'this is new');
$newNode->setAttribute('id', 'new_div');
// fetch and replace the old element
$oldNode = $dom->getElementById('old_div');
$oldNode->parentNode->replaceChild($newNode, $oldNode);
// print xml
echo $dom->saveXml($dom->documentElement);
Technically, you don't need XPath for this. However, it can happen that your version of libxml cannot do getElementById for non-validated documents (id attributes are special in XML). In that case, replace the call to getElementById with
$xp = new DOMXPath($dom);
$oldNode = $xp->query('//div[@id="old_div"]')->item(0);
Demo on codepad
To create a $newNode with child nodes without having to to create and append elements one by one, you can do
$newNode = $dom->createDocumentFragment();
$newNode->appendXML('
<div id="new_div">
<p>some other text</p>
<p>some other text</p>
<p>some other text</p>
<p>some other text</p>
</div>
');
首先使用jquery hide（）来隐藏特定的div，然后使用append来追加新的div
$('#div-id').remove();
$('$div-id').append(' <div id="new_div">this is new</div>');