Looking for Advanced Apple Scripting Resources

I cam across the following post by @Camelot and I was wondering where I can go to learn about the code provided and look at the documentation.

AppleScript for Message Received - Apple Community

Code (And post) In question: (From @Camelot)

using terms from application "Messages"

on message receivedtheMessagefromtheBuddyfortheChat

-- YOUR CODE HERE

end message received

on received text invitationtheTextfromtheBuddyfortheChat

accepttheChat

end received text invitation

on received audio invitationtheTextfromtheBuddyfortheChat

accepttheChat

end received audio invitation

on received video invitationtheTextfromtheBuddyfortheChat

accepttheChat

end received video invitation

on received file transfer invitationtheFileTransfer

accepttheFileTransfer

end received file transfer invitation

on buddy authorization requestedtheRequest

accepttheRequest

end buddy authorization requested

# The following are unused but need to be defined to avoid an error

on message senttheMessagefortheChat

end message sent

on chat room message receivedtheMessagefromtheBuddyfortheChat

end chat room message received

on active chat message receivedtheMessage

end active chat message received

on addressed chat room message receivedtheMessagefromtheBuddyfortheChat

end addressed chat room message received

on addressed message receivedtheMessagefromtheBuddyfortheChat

end addressed message received

on av chat started

end av chat started

on av chat ended

end av chat ended

on login finishedfortheService

end login finished

on logout finishedfortheService

end logout finished

on buddy became availabletheBuddy

end buddy became available

on buddy became unavailabletheBuddy

end buddy became unavailable

on completed file transfer

end completed file transfer

end using terms from

The rest of the code is irrelevant for your needs, but is required to prevent Messages.app from choking on your script not knowing how to deal with events.

Next, save your script in ~/Library/Application Scripts/com.apple.iChat

It will now appear in Messages' preferences, under the 'AppleScript handler' option.

Now, for any event, Messages will invoke the appropriate handler in your script.

--End of Post--