How do I get a _received_ iCal event to run a script? - applescript

Question

I'm trying to write an Applescript that will make an outgoing Skype call at times scheduled by received invites from other parties.
I think I'm fine with the script to Skype's API to make the call, however I'm struggling with iCal with either method of
A) getting the script to run in the background and getting the time of all new events, or
B) getting the event alert to run a one-off script.
The issue with option B) is that although you can set events from within iCal so that the alert runs a script, I need to trigger this from events that have been received.
A typical example would be:
All scripts and iCal running on the Host
At 10am a User schedules an event (via google cal on portable device) for 3pm** and invites the the Host.
At 3pm the script on the Host uses Skype API to make a call to the User.
** this could just as equally be on a date in the future and the requirements still hold.
Many thanks for any advice!

Answer 1

Since iCal doesn't have any notifications (some applications do like iChat) you'll have to run a "stay open" applescript application. Something like this will do it for your "B" scenario. NOTE: you will have to add the path to your applescript file (the one that makes your Skype call) in the "applescriptPath" variable.
When launched it will get a listing of all the calendar events you have in iCal. It will then run itself every 5 minutes. When it runs it will check the current events against the list of events it originally made. If there are new events then your applescript will be added as an alarm to the new events. This way it keeps track of the current events between runs and only finds the new ones.
So this script should be a good starting point for you. Remember to save it as a stay-open applescript application. You probably will want to modify it. For example I have it checking every calendar for new events but you may have one particular calendar you want to target. Good luck.
property storedUIDs : {} -- we use this to check for new events, if an event is not in this list then it is new
global applescriptPath
on run
set applescriptPath to (path to desktop as text) & "myAlarm.scpt" -- the path to the applescript which is run as the alarm
end run
on idle
set newEvents to {}
tell application "iCal"
set theCals to calendars
set allUIDs to {}
repeat with aCal in theCals
tell aCal
set theseEvents to events
repeat with anEvent in theseEvents
set thisUID to uid of anEvent
set end of allUIDs to thisUID
if thisUID is not in storedUIDs then
set end of newEvents to contents of anEvent
end if
end repeat
end tell
end repeat
set storedUIDs to allUIDs
if (count of newEvents) is less than 5 then -- this will prevent the first run of the script from adding the alarm to every event
repeat with aNewEvent in newEvents
-- do something with this new events like add an alarm to run an applescript
set theAlarm to make new open file alarm at end of open file alarms of aNewEvent with properties {trigger interval:0, filepath:POSIX path of applescriptPath}
end repeat
end if
end tell
return (5 * 60) -- run every 5 minutes
end idle
on quit
set storedUIDs to {}
continue quit
end quit