Nextcloud 18: Fixing the public link share Gallery/Image slideshow

Since I upgraded to Nextcloud 18, the slideshow for public link shares stopped working (because they added a replacement for the current image viewing app).

I found the solution at https://help.nextcloud.com/t/new-photo-app-in-nextcloud-18/69949/20 by user “guddl“:

cd /var/www/nextcloud/apps
git clone https://github.com/nextcloud/gallery.git
cd gallery/js/vendor/dompurify/src
wget https://raw.githubusercontent.com/cure53/DOMPurify/1.0.11/dist/purify.js -O purify.js 
sudo -u www-data php /var/www/nextcloud/occ app:enable gallery

Just make sure to replace the apps path and – if needed – the user www-data and the PHP binary.