Re: ical schema based on 1 test case: mtg.ics

Dan, this is so great!

On 20 Dec 2002, Dan Connolly wrote:

>
> Following from our discussion today about the new workspace
>   http://www.w3.org/2002/12/cal/
>
> I took the test/mtg.ics file that timbl checked in,
> then I took ical2rdf.pl from 2000/10/swap, enhanced
> it to convert dates to YYYY-MM-DDTHH:MM:SS form,
> and produced test/mtg.rdf
>
> Then I put together a makefile that builds ical.rdf
> by running sniffSchema.n3 over the input data file.
>
> The result looks like this:
>
> <rdf:RDF
>   xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'
>   xmlns='http://www.w3.org/2002/12/cal/ical#'
>   xmlns:i='http://www.w3.org/2002/12/cal/ical#'
>   xmlns:x='http://www.w3.org/2002/12/cal/prod_apple#'
> ><Vcalendar rdf:about=''>
>     <calscale>GREGORIAN</calscale>
>     <prodid>-//Apple Computer\, Inc//iCal 1.0//EN</prodid>
>     <x:wrTimezone>US/Eastern</x:wrTimezone>
>     <version>2.0</version>
>   </Vcalendar>
>   <Vevent>
>     <sequence>3</sequence>
>     <dtstamp>2002-12-19T20:53:57Z</dtstamp>
>     <summary>icalendaring #rdfig meeting</summary>
>     <dtend rdf:parseType='Resource'>
>       <dateTime>2003-01-08T14:00:00</dateTime>
>       <tzid>US/Eastern</tzid>
>     </dtend>
>     <dtstart rdf:parseType='Resource'>
>       <dateTime>2003-01-08T13:00:00</dateTime>
>       <tzid>US/Eastern</tzid>
>     </dtstart>
>     <uid>CDC474D4-1393-11D7-9A2C-000393914268</uid>
>   </Vevent>
> </rdf:RDF>
>
> [you may get the occasional 403 error when
> surfing around 2002/12/cal/* ; the auto-public-chacl
> request was queued, but it hasn't been serviced yet.]
>
> Some design choices I'd like confirmation on...
> maybe these belong in the schema or in some
> other documentation...
>
> capitalization: RFC2445 specifies case insensitivity
> for the .ics equivalent of these class and property
> names, so it seems best to normalize. TimBL and I
> agreed that camelCase, the RDF convention, is
> the way to go. Hyphens in the .ics syntax are
> treated as word boundaries. Class names get
> initial caps.

I'd agree with this, assuming theer aren;t any issues with conversion
from icalendar.

>
> prodid: I really wanted to turn this into a URI
> to use as the namespace name for x- names, but
> due to look-ahead issues, I use a command-line
> arg for the x: namespace name.
>
> apple's extensions: I chose the name
>   http://www.w3.org/2002/12/cal/prod_apple
> for a namespace for apple's extensions. I haven't
> fixed the 404 there yet.
>
> calscale: previously, I treated GREGORIAN as a symbol
> (i.e. a URI) rather than a string. I backed
> that out because I don't think calscale is
> worth bothering with. I've never seen anything
> other than GREGORIAN, and the semantics
> of anything else isn't even specified by
> RFC 2445.
>

sounds fair

> datatypes: I'm mostly using lexical forms...
> the value type for sequence is integer,
> but I didn't put rdf:datatype="...integer" there;
> I just treated it as a numeral.

could you explain this a bit more, for those of us not so up on rdf
datatyping? Does that mean it will be in the schema but not in the data?
What about XML schema datatypes and dates?

> I'm turning ical value types in to interpretation
> properties
> (http://www.w3.org/DesignIssues/InterpretationProperties)
> in the case of dtstart and dtend, since the
> timezone stuff prevents those from being plain strings.
> ical2rdf.pl knows explicitly about ical value types;
> it converts dates from YYYYMMDD to YYYY-MM-DD.
>
>
makes sense.

> Stuff still todo:
>
>  * more data: my evolution calendar
>  * more data: timezone files
>
> In the process of doing the YYYY-MM-DD
> conversion, I'm sure the code regressed
> w.r.t. the swap/pim version of ical2rdf.
> So I more testing is needed to rcover
> the lost ground.
>
>  * converting back from .rdf to .ics,
> 	checking the round-trip
>
>  * export the information in the %ValueType
> 	array in the code into the ical.rdf schema
>
>
> Not to mention how-to style write up and such,
> which I count on other folks to do.
>

Let me know if you want me to do anything.

Libby

Received on Friday, 20 December 2002 10:14:27 UTC