W3C home > Mailing lists > Public > www-rdf-calendar@w3.org > November 2003

Re: The w3c test objects.

From: Libby Miller <Libby.Miller@bristol.ac.uk>
Date: Fri, 21 Nov 2003 23:54:36 +0000 (GMT)
To: ietf-calendar@imc.org
Cc: www-rdf-calendar@w3.org
Message-ID: <Pine.GSO.4.58.0311162052160.24862@mail.ilrt.bris.ac.uk>


(cross-posted for info - please don't reply to both lists, thanks)

On Sun, 16 Nov 2003, Doug Royer wrote:

>
>
> Libby Miller wrote:
>
> >
> >You can find our sample iCalendar files and the derived RDF files here:
> >
> >http://www.w3.org/2002/12/cal/test/
> >http://www.w3.org/2002/12/cal/
> >
> >

Thanks for having a look at these Doug.

> (A) I have seen these before. Some minor nits:
>
>  Many of the VALARMs have an ATTACH property that is not valid:
>
>         ATTACH;VALUE=URI:Ping
>
>  Extra CR LF's in them between components.

Sorry, could you clarify? the ics files in that directory are all
generated from tools which export iCalendar.

>
>  Some have no METHOD property - does that mean they are booked
>  like in CAP?

I'll have to look into that.

>
>  Some VEVENTs have no SUBJECT or DESCRIPTION.
>

Descriptions and summaries are optional, as I understand it - is that
incorrect?

> (B) RDF issues I have noticed in the examples:
>
>   I noticed that the RDF format drops the 'VALUE' parameter completely.
>

VALUE (as in VALUE=BINARY, VALUE=DATE) is handled in various ways within
the RDF model.
So in RDF whether something is text or a uri is a crucial distinction
handled by the RDF syntax. Whether something is a DATE or a DATETIME is
handled using different RDF properties.

I think the main thing is that we can roundtrip between the RDF and
iCalendar versions, so we aren't losing information - inevitably there
will be differences in the syntactic representation that are difficult
to explain as we are translating between two different representational
languages.

>   The RDF-cal has a 'class' tag, that is not the same as the iCAL
> 'class' tag.
>

hm, it's not intended to be different. All we have done is create uris
to represent the possible values for class, i.e. public, private,
confidential become

<class rdf:resource='http://www.w3.org/2002/12/cal/ical#private'/>

etc

this just fits in better with the way RDF works - it's much better at
matching URIs than strings.

>   The examples drop the CLASS property nd its PUBLIC, PRIVATE,
>   and CONFIDENTIAL values completely.
>
>   The RDF-cal does not distinguish between property values and parameters.

this distinction doesn't really matter to RDF :)
We don't think that matters as long as we can get back to the iCalendar
format as required.

>
>   I have yet to see an example of how multivalued values are treated.
>   Is the XML tag replicated or is the value just put in 'as is'?

Which properties were you thinking of? If there were (say) two
descriptions then you would just repeat the tag. I don't think we have
come across any iCalendar data with repeated tags yet. RDF has an
underlying model of object->property->object, so the syntax would
depend on whether the repeated tag translated into an RDF object or
property.

>
> (C) And there is an xCAL mailing list with low volume. It has not been used
>       in a while but the archives are online.
>
>     To subscribe send email to 'majordomo@inet-consulting.com' with
>     a subject of 'subscribe xcal-dev'.

thanks, will do.
>
>     Archives at:            http://inet-consulting.com/xcal-dev
>
>

Thanks again for taking a look at what we've been doing - it's very
useful to get such detailed feedback from the iCalendar community.

Libby
Received on Friday, 21 November 2003 18:58:36 UTC

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