What I am trying to do:
I have a need to send my clients .ics files that will populate their Outlook calendars as soon as they download and double click (and choose to populate their Outlook calendar).
When I am testing locally, the iCalendar code below works fine if I set Outlook to work offline - a UID is generated once for each event, I can use the same file again and again and a new event will not be generated - as the UID is recognized by Outlook as already existing. (so I can rely on the UID to update, and cancel as well)
The issue is that when I work with an online Outlook, a random UID (112 characters long) is generated every time I use the file to populate the calendar - even for the same events - so a duplicate event is generated every time!
Example for an .ics file:
BEGIN:VCALENDAR
VERSION:2.0
METHOD:PUBLISH
PRODID:-//PYVOBJECT//NONSGML Version 1//EN
BEGIN:VEVENT
UID:12345
DTSTART:20190715T020222Z
DTEND:20190715T030222Z
DESCRIPTION:Some fake summary - first event
DTSTAMP:20190715T010222Z
SEQUENCE:0
SUMMARY:this is the first event summary
END:VEVENT
BEGIN:VEVENT
UID:67890
DTSTART:20190715T040222Z
DTEND:20190715T050222Z
DESCRIPTION:Some fake summary - second event
DTSTAMP:20190715T010222Z
SEQUENCE:0
SUMMARY:this is the second event summary
END:VEVENT
END:VCALENDAR
If I generate an .ics file for the first event that was generated when Outlook is online (dragging and dropping out of the calendar) I see that Outlook has added a bunch of new fields:
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Microsoft Corporation//Outlook for Mac MIMEDIR//EN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Pacific Time (US & Canada)
X-ENTOURAGE-CFTIMEZONE:US/Pacific
X-ENTOURAGE-TZID:1
BEGIN:STANDARD
RRULE:FREQ=YEARLY;INTERVAL=1;BYSECOND=0;BYMINUTE=0;BYHOUR=2;BYDAY=1SU;BYMONTH=11
TZOFFSETFROM:-0700
TZOFFSETTO:-0800
DTSTART:20071104T020000
END:STANDARD
BEGIN:DAYLIGHT
RRULE:FREQ=YEARLY;INTERVAL=1;BYSECOND=0;BYMINUTE=0;BYHOUR=2;BYDAY=2SU;BYMONTH=3
TZOFFSETFROM:-0800
TZOFFSETTO:-0700
DTSTART:20070311T020000
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
UID:<a NEW 112 character id - NOT the one I added myself>
X-ENTOURAGE_UUID:81760164-FB2C-4421-B7AC-2E1791265F0A
X-MICROSOFT-EXCHANGE-ID:<base64, 140 character id>
X-MICROSOFT-EXCHANGE-CHANGEKEY:<base64, 32 character id>
DTSTAMP:20190715T023949Z
DTSTART;TZID="Pacific Time (US & Canada)":20190714T190200
DTEND;TZID="Pacific Time (US & Canada)":20190714T200200
LAST-MODIFIED:20190715T023949Z
SUMMARY:this is the first event summary
DESCRIPTION:Some fake summary - first event
ORGANIZER:MAILTO:<the real account owner email - my email>
SEQUENCE:0
X-MICROSOFT-CDO-BUSYSTATUS:BUSY
X-MICROSOFT-CDO-ALLDAYEVENT:FALSE
X-MICROSOFT-DISALLOW-COUNTER:TRUE
X-MICROSOFT-DONOTFORWARDMEETING:FALSE
X-MICROSOFT-CDO-INSTTYPE:0
END:VEVENT
END:VCALENDAR
What I tried:
- Modified:
METHOD:REQUEST - Added
X-WR-RELCALID:some_unique_idfrom this post - Sequence does not seem to help - it is only there to sort out if 2 UIDs are the same within the same file
- I added
ORGANIZER;CN=Fable mail:MAILTO:fable.mail@example.comto each event - it has the same issue as the UID, and is disregarded (my email is added as the organizer) - I added
ATTENDEE:MAILTO:somemail@email.comas suggested in this post, but it does not seem to make any difference
Is it because I am not using the recommended standard for the UID? It seems like a suggestion to prevent collisions, nothing more.
Thank you!
