[Kroupware] Re: Kolab RFC (IMAP Groupware Folders)

[Stephan Buys]

Hi Marc,

This is the detailed reply that I promised... Comments are inline.

On Wednesday 23 April 2003 10:51, Marc Groot Koerkamp wrote:
>    Please feel free to make contributions and send in comments to the
>    kroupware at mail.kde.org mailing list.
>
> I have some comments :-)
>
> Chapter 1:
> I miss the rfc for imap-acl support (RFC 2086). Sharing calendars,
> contacts requires inside imap requires the imap-acl extension.
>

Done I have added it.

> Chapter 2:
> In my opinion this RFC should only describe how to store vCards, vCalendar
> entries en Notes inside an imap mailbox. (remove Chapter 2)
>

I wanted to add some filler and can understand that this might be a bit off-topic.
I am going to indicate that the chapter is to be removed in the text and ask for
some comments on it.

> Chapter 4:
> The Rfc's for vCards, vCalendar should cover what can be stored inside
> those mime types.
> What's left for this RFC is the description of the rfc822 header and the
> mimestructure of the body. (Chapter 4)
>

I agree. Could you give me an example of  you would indicate it? I never
liked the fact that I copy/pasted the message contents but I am not very 
experienced in all the details of these things.


> 1.2 Related Documents
>
>    Other pertinent documents needed for implementation are:
>
>    [IMAP] -  (RFC2060) Specifies the server protocol that a [MUA] uses
>       to access [Groupware] information.
>
>    [iTIP] -  (RFC2446) Specifies the standard protocol for scheduling
>       between different applications.
>
>    [iMIP] -  (RFC2447) Specifies the transport of [iTIP] items through
>       email.
>
>    [iCAL] - FIXME - is this the same as vCal?
>
>    [vCard] - FIXME
>
>    [vToDo] - (RFC2446)
>

Added.

> 3. IGF Access Method
>
>    FIXME - In the KMail client the folders are all stored under a specific
>    folder. Would it be possible to have all the folders under the root
>    folder? Ie. INBOX, Contacts, Tasks, etc. on the same depth?
>
> The question is if the special folders should be located in the shared
> namespace, the personal namespace or a custom defined namespace. Private
> contacts should be located in the personal namespace.
>

Could you please explain? (I know the concept of namespaces) What I 
meant here was that does it have to be:
INBOX
	-Contacts
	-Calendar
	-Notes
	-Tasks

or:

INBOX
Calendar
Notes
Tasks
Contacts

ie. Doesn't it make sense to have the groupware folders as children of the root
folder?

>    FIXME - Describe the process whereby a UA logs into the IMAP server
>    and the transport is used. Security comes into this as well. Do we do
>    any special actions or do we just open the hardcoded folders?
>
> Security is arranged at admin level by setting ACL info on the folders. I
> can imagine that the folders for contacts, calendar events should not be
> listed if a client does a LSUB or a LIST request (acl -l). This requires
> that the client is aware of the folder names used for storing such date
> which implies that the foldernames are hardcoded.
>

Would this also be set up using ACLs? ie. is there a flag which can indicate
"do not list?" I will add this as a FIXME for comments. Or does imply a IMAP
extension? (Maybe that is a good idea?)

>    FIXME - What consideration is given to offline storage or is it
>    defined by the UA? Disconnected IMAP?
>
> By using UID and UIDVALIDITY a client can cache data. The client should
> validate the cache on init (check if the uid's are still available on the
> server and retrieve the new uid's (adapted events / contacts get a new UID
> if I'm correct)
>

I am going to delete this FIXME. Would it be correct to say that this is actually
handled by the Disconnected IMAP RFC?

>    FIXME - Should the UA have hardcoded folder names? Ideally there will
>    be fixed names for the folders with a translation done by the client.
>    This way different clients using different languages can use the same
>    store. Is this feasible?
>
> Yes, there should be hardcoded folder names.
>

I agree to this, but I dont think this is the way it was implemented in either
the Kolab or Bynari clients.

> 4. IMAP Groupware Folders
>
> 4.1 Contacts Folder
>
>    Each contact is represented as a multi-part MIME email with a [vCard]
>    attached in the user's IMAP contact folder.
>
>    vCard MIME Message:
>
>       Content-Type: Text/X-VCard;
>       charset="utf-8"
>       From: Stephan Buys <s.buys at codefusion.co.za>
>       Reply-To:
>       Bcc:
>       Organization: Code Fusion
>       X-KMail-Fcc:
>       To: Stephan Buys
>       Subject: Contact: Stephan Buys
>       Date: Sat, 5 Apr 2003 11:19:56 +0200
>       User-Agent: KMail/kroupware-RC1
>       Status: RO
>       X-Status: O
>       X-KMail-EncryptionState:
>       X-KMail-SignatureState:
>       X-KMail-MDN-Sent:
>       X-UID: 1
>
>       BEGIN:VCARD
>       VERSION:3.0
>       NAME:Stephan Buys
>       UID:rwxg4FeaU
>       FN:Stephan Buys
>       EMAIL:stephanb at codefusion.co.za
>       N:Buys;Stephan;;;
>       CLASS:PRIVATE
>       END:VCARD
>
>    FIXME - are there guidelines (should there be?) for retrieving the
>    contacts? Are they all retrieved at once?
>
> This is a client issue. With a large contact list a client can retrieve
> contacts with a search query.
>

Agreed. FIXME removed.

>    FIXME - Is this compatible with Bynari Insight Connector?
>
>
>    Each message is stored in the user's IMAP calendar folder.
>
>    FIXME - could the KMail guys explain the special format of the
>    Subject? (When accessing the IMAP store with "Groupware Disabled".
>
>    FIXME - Again. Any retrieval guidelines here? Should the UA only
>    retrieve messages according to a specific date? How will this scale?
>    See: Slow startup with many calendar entries - Andreas Gungl -
>    (4 April 2003) - [Kroupware] mailing list.
>
> I should add an extra rfc822 header, namely X-EndDate. If a client want to
> retrieve all the calendar entries in a bounded period the startdate isn't
> enough. By doing that the performance will increase because the client can
> retrieve all the calendar data for a bounded period (day, week month,
> whatever).
>

Added. Thanks.

>
>       BEGIN:VCALENDAR
>       PRODID
>        :REQUEST
>
>       BEGIN:VTODO

>
>       END:VTODO
>       END:VCALENDAR
>
>    FIXME - Again. What is up with the special subject?
>
> Like already said on the list, VTODO === vCalendar. Maybe TODO entries and
> EVENT entries can be distincted by an message flag if the imap-server
> support PERSISTANT FLAGS *
>

Wont they already be distinguished by the fact that TODO's are in the Tasks folder
and that EVENTS are in the Calendar folder?

Thanks again,
Stephan