Logging out prevented by a script that runs forever

Question

I have a script that needs to loop forever. Unfortunately, it doesn't quit when the user logs out, blocking the logout.
How can I either test if there's a logout pending (in which case the script can exit) or actually allow a logout to kill the script?
The alternate is to execute a non-looping script automatically every few minutes, but I don't know to do that without digging using cron somehow.

Answer 1

In a word - you're doing it wrong.
If your script looks like this:
on run
  repeat
    -- do something
  end repeat
end run
Then your script does not give the app any time to respond to system events, such as a quit or shutdown.
Instead you should write your script using an idle handler. The idle handler runs periodically (on a schedule you set), and allows the app to respond to the system in between each iteration:
on run
  -- nothing really happens here
end run
on idle
  -- do something - i.e. your code goes here
return 10 -- run again in 10 seconds
end idle