The designer lock
One person edits at a time
Taking the lock
The designer is off until you switch it on, with the switch at the top right of the designer. Switching it on takes the lock: from then on you are the only one who can save, until you switch it off again.
Without the lock the designer shows Designer is not active, and nothing can be edited.
Saves never overlap: from 7.3.0, while a save, a push or a load runs, a second Save (a double click, or Ctrl+S held) is ignored, so it cannot write a second backup or a second commit racing the first.
When someone else has it
While another user holds the lock, the designer shows Designer is in use by that user, and nothing else: no sections, no files.
The switch shows on but greyed out, with Locked by and the user’s name beside it. You can take the lock once they switch the designer off. Every designer open sees it at once when the lock is taken or freed, without a reload.
When two users switch the designer on at the same moment, one of them gets the lock. From 7.3.0 the other sees who holds it and every editor stays read-only, so nothing can be typed that could not be saved.
Releasing someone’s lock
An admin can free a lock that somebody else holds, for example when they went home with the designer open.
Release, beside Locked by, shows for admins only. It asks first: the user’s changes that were not saved are lost.
From 7.3.0 the user whose lock was released is told so, and by whom: Your designer lock was released by the admin’s name, with Unsaved changes can no longer be saved. Their designer does not take the lock back on its own; they switch it on again when they want to go on.
A forgotten lock
A lock nobody uses frees itself, so nobody waits on a designer that nobody has open.
The holder’s open designer keeps telling the server that it is still there. When the server has not heard from it for 5 minutes, because the browser was closed, the computer shut down or the network went away, the lock is free again. When the holder comes back to the designer, it takes the lock again if nobody else has. An admin’s release is the exception: the lock is not taken back after it.