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

[Jari Urpalainen <jari urpalainen nokia com>]

ext Michael Wyraz wrote:
> > > 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 is already an rfc: <http://www.ietf.org/rfc/rfc4791.txt>. 
Evolution's CalDAV backend mostly lacks freebusy reports (sure acl 
handling is totally missing). That said you can still start fixing it 
fairly easily (I do have some fixes at sf.net).
> 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.
>   
right, but in OSS world you have many of these implementations, why 
reinvent the wheel ?
> 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 assume quite many of us are trying to boost it ...
> 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.
>
>   
Perhaps I have to stop producing running code, I'm way too slow ;-)
br, jari