Re: [Evolution-hackers] Simple Calendar Protocol Connector for easy implementation of calendar servers

[Michael Wyraz <lists wyraz de>]

> > i've spent some time with research on different calendaring 
> > client/server implementations. I believe that most use proprietary or 
> > open but very complex protocols (e.g. CalDav) or protocols that are 
> > restricted to read-only access (e.g. WebCal).
> > On the other hand there are some really simple protocols which are 
> > not dedicated to calendar access (e.g. xmlrpc or json over http).
> > So the barrier for a developer of a calendar (i.e. a web calendar) to 
> > implement a bridge to evoluition is very high.
> >   
> hmm. <shameless rant> I've submitted an open source Apache module 
> implementation of CalDAV <http://sourceforge.net/projects/modcaldav/>. 
> I won't argue that it (implementation) is perfect but I'm inclined to 
> say that CalDAV _is_ pretty simple compared to many other new specs 
> (i.e. when you don't have to implement the whole http/dav stuff). The 
> only exception to this may be the iCalendar spec which is probably 
> even too flexible. Fortunately, there's this, many times forked 
> libical libary, which we can/should fix. And Evolution is a pretty 
> decent calendar client as well (although there are some missing 
> features). So with these constraints, I'll doubt that you could 
> significantly simplify or improve the situation by creating yet 
> another new spec ;-)
> br, jari 
Ok, the CalDAV spec is not extremely complex. But it depends on iCal, 
WebDAV and the CalDAV Spec (which is in fact not a spec but a draft that 
still might change). The current CalDAV draft (draft 15) was expired on 
March 17, 2007.
The evolution caldav connector is from December 2, 2005 
(ftp://ftp.gnome.org/pub/gnome/sources/evolution-caldav). It implements 
the protocol draft version 5 or 6...

CalDAV draft has 115 pages. WebDAV consists of at least 7 RFCs, the most 
important are together about 300 pages. ICal rfc has about 150 pages.

I know about 2 (free) servers (ok, since your mail, i know 3 :-) ) and 
maybe 5 clients which supports caldav. Most (all?) of them supports a 
subset and all implements different draft versions.

So in my opinion CalDAV is not a simple protocol. It's a big 
all-in-one-approach for calendaring with the cost of high implementation 
expense. It will not be implemented in many calendars until stable 
caldav-libs (client and server) are available.

I'd prefer a proprietary (in sence of non-standardized, but well 
documented) protocol which is easy to implement in a few hours or days. 
This gives progammers the opportunity to add client-support to their 
calendar servers whitout too much effort.

regards,
Michael.