Is the iCalUID of a google calendar event unique across all google calendar events ever created on all google calendar accounts?
That is, if my event has an iCalUID, is it guaranteed that if another google user creates an event, they will never have the same iCalUID as mine? I am not convinced by what the docs say but here is what the documentation says: Calender iCalUID and id documentation.
This is the reference for the documentation:https://developers.google.com/calendar/api/v3/reference/events
I appreciate any help I could get on this.
The difference between the iCalUID and the id is that the former stays the same for recurring events while a unique id is generated for every single occurrence of the event.
As per your first question, the iCalUID is generated when you create an event in a calendar, therefore it is not shared across calendar accounts (unless you add Calendar B as a guest to calendar's A event, in which case they would see the same event with the same ids in their respective calendars).
As per the ID collision, as it is stated in the documentation, Google does not fully guarantee that a provided id will be unique across its vast databases. Nevertheless, if the provided id is a moderately long random string of characters (this will be the case if one is not provided and Google auto generates one), the probabilities of an id being repeated are extraordinarily low (as there are many, many more random combinations of, say, 15 characters than there are calendar events in the whole world).
Having said that, your data is still secure, as Google will not display your events to anyone who has not provided proper authorizing credentials (in the same manner that you cannot fetch via the API other user's events even if you know their ids).
