Subject: [Ietf-calsify] XML format?

From: stpeter at jabber.org (Peter Saint-Andre)
Date: Wed Oct 6 18:51:01 2004

Is anyone thinking about doing an XML format for calendaring and 
scheduling data?

Peter

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From: TimHare at comcast.net ([email-masked])
Date: Wed Oct 6 19:33:06 2004

Please look at: http://www.ietf.org/internet-drafts/draft-hare-xcalendar-01.txt

Suggestions and opinions are appreciated.

At 09:38 PM 10/6/04, Peter Saint-Andre wrote:
>_______________________________________________
>Ietf-calsify mailing list
>[email-masked]
>http://lists.osafoundation.org/mailman/listinfo/ietf-calsify

Tim Hare
Interested Bystander, Non-Inc.

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From: stpeter at jabber.org (Peter Saint-Andre)
Date: Wed Oct 6 19:51:00 2004

In article <[email-masked]>,
 [email-masked] wrote:

> Please look at: 
> http://www.ietf.org/internet-drafts/draft-hare-xcalendar-01.txt

Thanks, I'll have a look at that.

/psa

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From: stpeter at jabber.org (Peter Saint-Andre)
Date: Mon Oct 11 16:15:09 2004

> Suggestions and opinions are appreciated.

In Section 8, you recommend using the HTTP URIs of the RFCs as XML 
namespace names. This is potentially problematic (what happens when ther 
are superseded?). I'd suggest XML namespace URIs in the 
urn:ietf:params:xml:ns tree (RFC 3920 is a recent spec that uses these).

In Section 9, your media types are off -- "application/calendar+xml" is 
more correct. http://www.xmpp.org/specs/rfc3923.html#iana has an example 
of a recent content-type registration of this kind. When the time comes, 
don't forget to run your definition by the friendly folks on the 
ietf-types list: http://www.alvestrand.no/mailman/listinfo/ietf-types

In Section 11.1 you define a DTD. That's so old-fashioned -- all the 
cool kids are using XML schema these days. ;-)

That's about as far as I got. It'll be great to have an XML format for 
calendar objects!

Peter

P.S. Given some of the layout oddities, it seems that perhaps you did 
not use the XML RFC format; http://xml.resource.org/ tells you how and 
it is highly recommended!

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From: lisa at osafoundation.org (Lisa Dusseault)
Date: Mon Oct 11 16:38:04 2004

Peter's mail reminded me that whenever I talk about calendaring 
standards outside the group of calendaring implementors, people always 
ask about an XML format for calendar data.  For example, Paul Hoffman 
explained to me last week why Atom (blog feed format) would only use 
XML but that if iCalendar had some XML data format standards they would 
be happy to be compliant with that for dates, durations, attendee lists 
or what have you.

Doing a non-backward-compatible switch from iCalendar 1.0 to something 
XML-based would certainly have a big switchover cost in calendaring 
software.  But moving to XML would certainly have long-term synergy 
with other standards groups, benefits in terms of fewer format parsers, 
greater flexibility and greater interoperability.  I don't even know 
how we can estimate when the benefits outweigh the costs, or at what 
rate the costs would be amortized, but it does seem clear to me that 
the switchover cost is more temporary while the benefits are longer 
lasting.

Lisa

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From: TimHare at comcast.net ([email-masked])
Date: Tue Oct 12 05:00:53 2004

I believe XML has a lot of benefit for calendaring, also (one of the 
reasons for 
http://www.ietf.org/internet-drafts/draft-hare-xcalendar-01.txt). I am NO 
expert in XML but I am a believer in the benefits of markup from a long 
time ago.

I think, however, that if we're going to discuss it, we need another 
mailing list. I wouldn't want to muddle "iCalendar simplification" with 
"redoing the calendaring idea".  The RDFiCalendar folks should be invited 
as well since they've already got an XML implementation, and they tried to 
build "round-tripping" tools between that and iCalendar. My only issue with 
their implementation so far is that "I'm just a simple caveman..." and the 
theoretical aspects of why they choose to do things in certain ways,  have 
escaped me so far.

At 07:37 PM 10/11/04, Lisa Dusseault wrote:
>Peter's mail reminded me that whenever I talk about calendaring standards 
>outside the group of calendaring implementors, people always ask about an 
>XML format for calendar data.  For example, Paul Hoffman explained to me 
>last week why Atom (blog feed format) would only use XML but that if 
>iCalendar had some XML data format standards they would be happy to be 
>compliant with that for dates, durations, attendee lists or what have you.
>
>software.  But moving to XML would certainly have long-term synergy with 
>other standards groups, benefits in terms of fewer format parsers, greater 
>flexibility and greater interoperability.  I don't even know how we can 
>estimate when the benefits outweigh the costs, or at what rate the costs 
>would be amortized, but it does seem clear to me that the switchover cost 
>is more temporary while the benefits are longer lasting.
>
>Lisa
>

Tim Hare