ZmZimletBase gives us several hooks, like onMsgView, onContactView, etc. but there doesn't appear to be a similar hook for viewing a a calendar appointment item (onAppointmentView?). I can use onShowView to detect when the appointment view is brought up, but I don't have access to the appointment object.

Background: I need to modify the UI when a user edits an event for which they are an invitee but not the organizer. ZmCalItemView.js: traps for this by checking item.isOrg, but I can't do that without access to the appointment object.