DOMDocument, get the text in an element that follow a found element - php

Question

I'd like to get the text for the ul>li that immediately follows the with the text ABC. The text in this case would be 123.
<h2>CDE</h2>
<ul>...</ul>
<h2>ABC</h2>
<ul>
<li>
<span>123</span>
</li>
</ul>
This is what I have, but it's not working
$dom = new DOMDocument();
$dom->loadHTML($html); // $html is the code above
$h2_all = $dom->getElementsByTagName('h2');
foreach($h2_all as $h2) {
$h2_text = $h2->textContent;
if (trim(strtolower($h2_text)) == 'abc') {
var_dump($h2->nextSibling);
}
}
I assume it's because $h2 doesn't contain the ul data I need, but I'm not sure how to get it.

Answer 1

You can use an xpath query:
$dom = new DOMDocument;
$dom->loadHTML($html);
$xp = new DOMXPath($dom);
$qry = '//ul[preceding::h2[1] = "ABC"]/li/span';
$result = $xp->query($qry)->item(0)->nodeValue;
query details:
// # the path can start from anywhere in the dom tree
ul
[preceding::h2[1] = "ABC"] # condition: the first preceding h2 has the value "ABC"
/li/span # lets continue the path until the span node

Answer 2

Check the siblings and find the first ul:
$ul = null;
foreach($dom->getElementsByTagName('h2') as $h2) {
if(trim(strtolower($h2->textContent)) == "abc") {
$obj = $h2->nextSibling;
while($obj != null) {
if($obj->nodeName == "ul") {
$ul = $obj;
break 2;
}
$obj = $obj->nextSibling;
}
}
}
//make sure ul has at least one li
if($ul != null && $ul->firstChild != null) {
echo $ul->firstChild->nodeValue;
}