3
FS, I am getting really really annoyed with the lack of overview of the code!
Here I am, asking for functionality which is already there and noone has been able to point that out to me.
XoopsGroupPermHandler::getItemIds($gperm_name, $gperm_groupid, $gperm_modid = 1) WILL return those categories, a certain group is permitted in a certain module with a certain permission name.
Now I only need one, which takes a group array and does the same - but anyways, this is somewhere to start.
Edit: Groups CAN be an array... so all requested functionality is there - why does this have to be such a secret???