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Re: New RDFa Primer Draft (calendar details)

From: Dan Connolly <connolly@w3.org>
Date: Mon, 24 Apr 2006 17:41:04 -0500
To: Ben Adida <ben@mit.edu>
Cc: public-rdf-in-xhtml task force <public-rdf-in-xhtml-tf@w3.org>
Message-Id: <1145918465.27608.952.camel@dirk.w3.org>

On Sat, 2006-04-22 at 12:14 -0400, Ben Adida wrote:
> 
> Hi all,
> 
> http://www.w3.org/2001/sw/BestPractices/HTML/2006-04-24-rdfa-primer
> 
[...]
> 
> 2) Section 2 is entirely rewritten, thanks to a very productive  
> offline discussion with MarkB (and a suggestion due also to DanC). In  
> particular, we stay away from the URI ambiguity issues by using  
> vocabularies (iCal and vCard) that are less people-oriented. This  
> also seems like the right way to show people the power of RDFa: there  
> are interesting, natural things to share in current web pages, like  
> events and contact information, that RDFa can address quite well.

Yes, the calendar example is nice.

a detail... as to:

  <meta property="cal:dtstart" content="20060508T1000-0500">

iCalendar doesn't allow 20060508T1000-0500 as a dtstart,
and neither does http://www.w3.org/2002/12/cal/ical .

http://www.w3.org/2002/12/cal/ical is a schema that we don't
currently maintain test cases for, though it's still somewhat
used and we might return to it. There's still some supporting
code at http://www.w3.org/2002/12/cal/ical2rdf.pl

If you run it on a .ics file, e.g.
  http://www.w3.org/2002/12/cal/test/cal01.ics
you'll get dates like:

    <dtstart rdf:parseType='Resource'>
     <dateTime>2002-06-30T09:00:00</dateTime>
     <tzid>/softwarestudio.org/Olson_20011030_5/America/New_York</tzid>
    </dtstart>

So note 3 things:
(1) these use XML Schema date syntax, including all the punctuation
(2) timezones are expressed as separate properties
(3) the object of the dtstart property isn't a literal; to
get to the time literal, there's another <dateTime> property.

The newer schema is http://www.w3.org/2002/12/cal/icaltzd

It models timezones as datatypes, which is an idea that I'm not
sure is going to stick. But it looks like:

<dtstart

rdf:datatype="http://www.w3.org/2002/12/cal/tzd/America/New_York#tz"
          >2002-06-30T09:00:00</dtstart
        >

I see you cite the RDF calendar workspace; it might be better
to cite the IG Note:

RDF Calendar - an application of the Resource Description Framework to
iCalendar Data
W3C Interest Group Note 29 September 2005
http://www.w3.org/TR/rdfcal/


The issue of timezones and the 2 different schemas are discussed
in section 11. Shop hours, recurring events and timezones
http://www.w3.org/TR/rdfcal/#L21805


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Monday, 24 April 2006 22:44:16 GMT

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