Clearing property upon restart

Question

This pertains to an AppleScript application -- not an AppleScript Studio app.
The script generates information which must persist through relaunches but which becomes totally obsolete if the computer is shut down.
Stored as a property, the information does of course persist through relaunches -- but also through restarts. Thus, after a restart, the script immediately starts working with obsolete information.
I'm looking for a way of clearing the property, but only after the computer is restarted. The only approach that comes to mind is to write another script which clears the property and include it as a login item -- but I'd prefer a simpler approach. Anybody?

Answer 1

Hello
Your script will fail, e.g., in the following scenario:
1) Run the script at 60 seconds after a restart.
2) Restart the computer.
3) Run the script at 65 seconds after the last restart.
After 1), TicksAtPreviousLaunch = 60 * 60.
In 3), property won't be reset though the script is run for first time after the last restart because TicksAtThisLaunch = 60 * 65 > TicksAtPreviousLaunch.
Instead, you may try something like this alternative.
-- SCRIPT1
(* using 'the ticks' of Jon’s Commands (provided that 1 tick = ca. 1/60 second) *)
property lastStartup : (current date) - ((the ticks) div 60)
property lastLaunch : lastStartup - 100
property runCount : 0
initAtFirstRunSinceRestart()
set runCount to runCount + 1
return runCount
on initAtFirstRunSinceRestart()
set lastStartup to (current date) - ((the ticks) div 60)
if lastLaunch < lastStartup then -- 1st launch since last startup (or last compilation)
set lastLaunch to current date
set runCount to 0 -- initialize some properties
end if
end initAtFirstRunSinceRestart
-- END OF SCRIPT1
A few other things.
• As far as I know, Jon's Command is PPC only and cannot be used in x86 Mac.
• In order to pass a name of property to a handler that will set the property's value, you'll have to pass reference to the property and dereference it in the handler. Something like this, if you really want to do it...
-- SCRIPT2
property x : 0
init(a reference to x)
return x
on init(xref)
set xref's contents to 1
end init
-- END OF SCRIPT2
Hope this may help,
H
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  Mac OS 9.1.x