Remove parent nodes if contains tag - domdocument

Question

I'm trying to remove url elements from my sitemap if they contain a priority tag. What am I doing wrong?
Script:
<?php
$xml = new DOMDocument;
$xml->load('sitemap.xml');
$priorities = $xml->getElementsByTagName('priority');
foreach($priorities as $priority){
$xml->removeChild($priority);
}
echo $xml->saveXML();
Existing sitemap:
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<url><loc>https://www.example.tld/</loc></url>
<url><loc>https://www.example.tld/file</loc></url>
<url><loc>https://www.example.tld/folder/</loc><priority>0.7</priority></url>
<url><loc>https://www.example.tld/folder2/</loc><priority>0.3</priority></url>
</urlset>
Desired sitemap:
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<url><loc>https://www.example.tld/</loc></url>
<url><loc>https://www.example.tld/file</loc></url>
</urlset>

Answer 1

You have to use the parentNode of $priority instead of $xml to remove the child.
Instead of using a foreach, you can loop the collection using a for loop decrementing the value of $i
$xml = new DOMDocument;
$xml->load('sitemap.xml');
$priorities = $xml->getElementsByTagName('priority');
for ($i = $priorities->length - 1; $i >= 0; $i--) {
$priorities[$i]->parentNode->removeChild($priorities[$i]);
}
echo $xml->saveXML();