[dev] iCal spec for UID values - persistence question

[Kevin Myer]

http://bugs.horde.org/ticket/?id=1107 was a bug I filed awhile back.  Chuck
thinks the current code works correctly but I still think my original report
captures the essence of a problem with the way Kronolith generates UIDs for
events.  Now that got me thinking to other similar cases, where Kronolith might
start generating UIDs and that would occur in importing calendar data from an
outside source.  That further led me to question whether or not UIDs are unique
to a system, or whether they are intended to be globally unique - i.e., if you
could export from one system, import to another, export from that and import
back into the original and the UID would be the same.

A quick read of the specs would seem to indicate that the above scenario _maybe_
should work, as it states that:

"Implementations MUST be able to receive and persist values of at least 255
characters for this property."

I would think that if you have to persist something, that means you have to keep
it.

A quick test export from Kronolith into Apple's iCal showed me that either my
interpratation was wrong, or Apple's interpretation was wrong.  When the events
came back out of iCal, they had Apple UID's (ironically enough, Apple appears
to use the machine MAC address as part of the id...)  Importing a test event
invitation request turned up another quirk - time is displayed in GMT when the
event notification dialog pops up but is in the local time zone for the
calendar event item.

So can anyone who knows the iCalendar spec better than I comment on the state to
which UIDs should persist?  Or has anyone worked with other iCalendar
conforming application, and can test to see what happens to a UID for an event
that is imported and exported from the system?

I'd think that Kronolith should maintain UIDs if they already exist, for both
within Horde (which would fix my initial bug report of this) and for events
generated from external systems (which would then allow me to implement a poor
man's type of sync to Apple's iCal, for offline access for certain staff
members that don't have Internet connectivity most of the week - of course, I
have to get Apple to use persistent UIDs too..)

Thoughts?

Kevin

-- 
Kevin M. Myer
Senior Systems Administrator
Lancaster-Lebanon Intermediate Unit 13  http://www.iu13.org
(717) 560-6140