How do I edit existing Calendar Events with Applescript?

Question

I've got a script that needs to add a URL to an existing Calendar event.  I've tried everything I can think of but can't get it to work.  Here's what I've got so far, that's working, but it's missing the last piece:
tell application "Finder"
          set icsFile to POSIX path of ("Macintosh HD:Users:user:Library:Calendars:icsfile" as alias)
          set eventID to do shell script "cat " & quoted form of icsFile & " | grep -m 1 'UID:' | sed s/UID://"
          set hangoutLink to do shell script "cat " & quoted form of icsFile & " | grep 'X-GOOGLE' | sed s/X-GOOGLE-HANGOUT://" as URL
end tell
tell application "Calendar"
          get name of every calendar
          tell calendar "example calendar"
                    set theEvent to first event whose uid = eventID
  --here's the bit I can't get working
                    tell event theEvent
                              set properties to {url:hangoutLink}
                    end tell
          end tell
end tell
When I run it, I get the following error:
Calendar got an error: Can’t make event id "[email protected]" of calendar id "6B53911E-829F-4CCA-90F9-0A493B8DF3F5" into type integer.
Thanks in advance for any help!

Answer 1

The properties of the text should still be set to the text tool if it was the previous text used, otherwise I'm not to sure.