If you don’t have those users managed in some external application then you could do something like this:
def load_csv(path)
CSV.parse(File.read(path), headers: true)
end
def update_group
g=Group.find(43) #whatever group ID yo uwant
GroupUser.where(group_id: g.id).destroy_all
user_emails=load_csv('/path/to/file')
user_emails.each do |u|
user = User.find_by_email(u['Email'])
next unless user
puts "found user #{uid}"
GroupUser.find_or_create_by(group_id: g.id, user_id: user.id)
end
end
Just how is a whole nother issue. A plugin, perhaps.
Maybe a plugin that automatically adds a user to the group if they post in the category?