Hide sidebar content if user not logged in

[timjcraig]

Is it possible to enable security with login plugin for sidebar? Access is set pages but anonymous user can still view page titles on sidebar.

[ilu33]

Even when using the maintenance plugin the navigation stays visible. This must be a bug #82.

I actually noticed this because - like a lot of others - I'm desperately looking for a way to make my whole site visible only to registered users. I don't want anybody else to see anything but the login window. And I don't dare to rely on the private plugin that is not officially supported and hasn't seen any action for a year (and seems to have the same problem https://github.com/Diyzzuf/grav-plugin-private-site/issues/6).