Re: [calsify] The two ways of cancelling an event by an organizer

[Дилян Палаузов <[e-mail]>]

Hello Doug,

it is more practical if the iCalendar resources are uploaded via HTTP to the server and then the server decides how to
deliver the transport independent information: to local users via HTTP CalDAV scheduling, for remote users by sendnig
iMIP.

In theory it is possible, that the CUA updates the iCalendar object for the local users on two subsequent HTTP
operations, and for the remote users sending itself the iMIP messages, playing with the SCHEDULE-AGENT property
parameter per ATTENDEE.  So for an event with local and remote attendees, the iCalendar objects is distributed partially
by the server and partially by the clients.  However this moves complexity from the server to the client, or rathar
expects that the same functionality is implemented in both server and client, and, depending on the locality of the
user, the transport independent message is sent either be client or by the server.  Moreover, the CUA has to figure out,
if a user is local or remote, and so on.

It would be simpler, if the the intension of the organizer is mapped to the HTTP protocol and the server sends in
transport independend ways what the organizer asked for.  The one approach is to define payload to DELETE.

The other would be to send METHOD=CANCEL messages, when the iCalelendar object has STATUS:CANCELLED.  So everytime the
organizer modifies a cancelled invitation, the attendees get a new cancellation message with increased SEQUENCE.  When
the organizer deletes a message with STATUS:CANCELLED, the attendees get, or not, one more cancellation message.  Or the
intention of the organizer is read from the STATUS parameter and not from METHOD.  So an iCalendar object with
STATUS:CANCELLED and METHOD=REQUEST is cancelled... I do not know what would be right.

Now I think that not only orginizer has two ways to cancel an event: set STATUS to CANCELLED or delete the event, but
also the attendees have two ways to act on receiving events cancellation: set STATUS to CANCELLED or delete the local
copy of the event.

Regrads
  Дилян



On Wed, 2019-08-07 at 16:01 -0600, Doug Royer wrote:
> On 8/7/19 3:03 AM, Дилян Палаузов wrote:
> > Hello Doug,
> > 
> > to force the server to use METHOD=CANCEL, the CUA has to use the HTTP DELETE verb.  It is not possible to add anything
> > to the deleted object, as DELETE currently does not have payload.
> > 
> > To modify the iCalendar object, like changing the description or adding comment, one has to use the HTTP PUT verb.
> > 
> > When HTTP PUT is used, one iMIP message is generated and when HTTP DELETE is used, another iMIP message is generated.
> > 
> > Regards
> >    Дилян
> 
> As your talking iMIP, can you send them an email that describes the reason, and includes attaches (multipart related) the CANCEL object or CANCEL object URL?
> 
>