Hi, BobRay!
Thank you for helping me, and sorry for my English))
I will try to explain in other words)) If you are in the admin panel, then in the top menu choose system->types of content (it is below dictionary setting and above the contexts setting, I'm translating from russian so the name could vary slightly).
You will see mime types and file extensions. This extension is used as url suffix for child documents in modx. So if you put ".html for text/html types of files the url will be yoursite.com/mainpage.html and if you change it to "/" the url will be changed to "yoursite.com/mainpage/"
I attached the screenshot with the setting I need to get access.
I need to get the setting from this tab for text/html files.
I'm not able to use the function you've mentioned as it requires the modResource, so it should be used as follows:
$resource = $modx->getObject('modResource', 1);
$output = $resource->getOne('ContentType')->get('file_extensions');
echo $output;
as soon as I have resources stored in the own table this will not work: $output = $resource->getOne('ContentType')->get('file_extensions');((