A feature request for Apple and Microsoft, and other OS developers. A way for an app to subscribe to a folder. I give you a callback and a folder. If a file is added, deleted, renamed or edited in the folder, call me with a path to the file. [Scripting News]
I would write a daemon that you would tell to monitor one or more folders with an action to take if anything changes in that folder. It would use unix-style configuration files (similar to crontab) with a command-line action. Since you can run an AppleScript from the command line using the ‘osascript’ command, this gives you the flexibility to do pretty much anything.
Couldn't you do all of this already with Folder Actions in OS X 10.2 and Mac OS 9?
FNSubscribe/FNNotify are the official ways of doing this in OS X, but not everything uses them.
Yes, I just saw the note on Scripting News. FNSubscribe looks like a nice clean way to do it.