[Kolab-devel] CalDav reaches the standards track

[Martin Konold]

Am Mittwoch 28 März 2007 schrieb Stephan Buys:

Hi Stephan,

> http://www.calconnect.org/

> CalDav reached the standards track on 20 March 2007. I propose that the
> Kolab project should seriously support CalDav via our Horde web interface.
> This will allow us to inter-operate with other standards-based clients as
> they mature/are released.

Please explain this to me in more detail. 

I have the impression that CalDAV is an _ACCESS_ protocol about how to access 
calendar data over WEBDAV/HTTP.

Kolab currently uses IMAP not HTTP.

Technically a server component offering CalDAV to clients would be a special 
Kolab client. It can be developed orthogonally to the current Kolab effort. 

If it is properly implement it will not interfere with the other Kolab 
components and I am therefore willing to accept such an effort.

The situation is very similar to the upcoming Horde based Kolab webclient. The 
Horde Kolab Client is technically a server application offering a HTTP/HTML 
interface to users.

BTW: I have to admid that I am not fond of Calendaring Extensions to WebDAV 
(CalDAV). The definition requires 99 pages for the _access_ definition alone 
while not solving any issues with the existing iCalendar standard. I have the 
impression that CalDAV was written with relational databases in mind while I 
believe that calendaring is by its very nature _not_ well suited for a RDBMS.

(It is a fundamental design decision of Kolab to use a hierarchical store 
instead of a relational db. Kolab uses IMAP for access/transport because it 
is very well suited to provide extremly efficient access to messages in such 
a hierarchical store.)

From an conveptional/architectural point of view access/transport is a _very_ 
minor issue or problem to solve. The real problems are true scalability(*), 
modelling issues and interoperability. Especially the later (Outlook!) is the 
most difficult part for which CalDAV does not help in any way.

Regards,
-- martin

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