Itunes Applescript event

Question

I am writing a jukebox application that uses a php/js as a frontend and uses itunes as a backend. The problem is I need a way to tell when a song has stopped playing in itunes. I have thought of using a idle script to poll itunes via applescript. But, I would have to poll every so many seconds, instead I would like a event to run a applescript when the song stops playing. Any ideas?

Answer 1

iTunes sends out a system wide notification whenever it's state changes called "com.apple.itunes.playerInfo". So if you can register for system notifications (NSDistributedNotificationCenter) from php then that would be the way to go rather than polling. A quick search turned up this for how to do it from python... here.

Answer 2

I'm not entirely sure if a method exists that allows you to do that, but for now you could always use iTunes' player state property, which tells you what iTunes is currently doing by returning one of the following five values:

playing, stopped, paused, fast forwarding, rewinding

Using that property, you can then create a repeat until player state is stopped loop with no commands inside of it (in essence, wait until the song currently playing is stopped), then after the loop, execute whatever you want. Translated into code, this paragraph reads:

tell application "iTunes"
   repeat until player state is stopped
      --do nothing until the song currently playing is stopped...
   end repeat
   --[1]...and then execute whatever you want here
end tell

OPTIONAL

If you only want to run the script once, you could insert the above script into an infinite repeat loop, although you might want to delay a bit first to allow you to start a song. Otherwise, [1] will execute immediately after you start the script (assuming no songs are in use).

Code

repeat
  delay 60 --1 minute delay
  tell application "iTunes"
     repeat until player state is stopped
         --wait
     end repeat
     ...
  end tell
end repeat

If you have any questions, just ask. :)