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Re: RDFa and Microformats

From: Martin McEvoy <martin@weborganics.co.uk>
Date: Sun, 14 Sep 2008 18:20:26 +0100
Message-ID: <48CD47DA.6090001@weborganics.co.uk>
To: Simone Onofri <simone.onofri@gmail.com>
CC: Ben Adida <ben@adida.net>, Toby A Inkster <mail@tobyinkster.co.uk>, RDFa <public-rdf-in-xhtml-tf@w3.org>

Hello Simone.

Simone Onofri wrote:
> Hi Martin,
> [there are more cuts...]
>>> If you want to use microformats *exactly* as is, you have to vary your
>>> parsing rules based on the microformat in question, and the best way to
>>> do that is, as Toby has mentioned, using GRDDL and @profile. We may
>>> eventually be able to use @profile to feed the RDFa tools pipeline, but
>>> not yet.
>>> What we discussed recently is the possibility of making the prefix story
>>> simpler for microformats-*like* markup, but still using @rel, @property,
>>> @typeof consistently. We still need to work on that, but note that we're
>>> *not* talking about subsuming existing microformats as-is into generic
>>> RDFa, as that would make RDFa parsing vocabulary-dependent. That would
>>> break a lot of the goodness of RDFa.
>> Yes and the goodness of GRDDL, In fact I am beginning to believe that
>> Microformats And RDFa are not well suited at all and the whole idea was and
>> Interesting but pointless discussion. This I think is because Both
>> Microformats and RDFa use GRDDL profiles, One or two GRDDL applications
>> Redland, ARC that I know of Parse hCards by default without using a
>> transformation link, just using the data-view profile see:
>> http://librdf.org/parse?language=grddl&uri=http://weborganics.co.uk/demo/hcard.xhtml,
>>  so what if I were to mix that with some RDFa, see:
>> http://librdf.org/parse?language=grddl&uri=http://weborganics.co.uk/demo/hcard-RDFa.xhtml,
>> Triples are repeating themselves but in different contexts, thats not
>> exactly a defining "meaning", It only brings myself to ask Why use RDFa in
>> my markup when Microformats are easier?
> There are a lof of reasons to use RDFa instead Microformats, depending
> on context and the meaning of "easier".
> Easier for tools and implementations? Microformats have actually more
> datas expressed in this way and more tools... but this can be
> temporary... and RDFa community is deploying tools and 'cut and paste'
> templates. What do You need exactly?
A free Extension for Dreamweaver would be good, to make it easy for 
every day authors to publish RDFa. :-)
> As for my experience - in XHTML writing - RDFa is quite good....
> First for accessibility: using the @title on acronyms, screen readers
> read the date in ISO format, not suitable for humans... and this is
> not good for Microformats.... for other question Steven Pemberton
> wrote about BBC and Microformats.
And you guys said to the BBC use RDFa, that in my view was not the 
answer. Did the BBC want the output of hcalendar on hcard to be RDF?  or 
did the BBC want their user to be able to export a vcard to their 
address books, or subscribe to iCal or webCal in their calendars? RDFa 
Can help in my view, just by being microformats aware Did anyone ask 
those questions.

Microformats and RDFa  work amazingly well together, if the output is 
RDF  you have to understand that microformats produce their own triples, 
its particularaly useful in hcalendar I have made an example see: 

this is the mark-up

> <?xml version="1.0" encoding="UTF-8"?>
> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN"
>       "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd">
> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
>     <head profile="http://www.w3.org/2003/g/data-view">
>         <link rel="transformation" 
> href="http://ns.inria.fr/grddl/rdfa/2008/08/07/RDFa2RDFXML.xsl" />
>         <title>hCal RDFa</title>
>     </head>
>     <body>
> <div class="vevent">
>  <a class="url" href="http://www.web2con.com/">http://www.web2con.com/</a>
>   <span class="summary">Web 2.0 Conference</span>:
>   <span property="dtstart" content="2007-10-05">October 5</span>-
>   <span property="dtend" content="2007-10-20">19</span>,
>  at the <span class="location">Argent Hotel, San Francisco, CA</span>
>  </div>
>     </body>
> </html>
here are the the resulting triples using  : 

> <?xml version="1.0" encoding="utf-8"?>
> <rdf:RDF xmlns:c="http://www.w3.org/2002/12/cal/icaltzd#" xmlns:h="http://www.w3.org/1999/xhtml" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns="http://www.w3.org/1999/xhtml/vocab#" xml:base="http://triplr.org/rdf/weborganics.co.uk/demo/hcal.xhtml">
>   <c:Vcalendar rdf:about="http://weborganics.co.uk/demo/hcal.xhtml">
>     <dtstart xml:lang="en">2007-10-05</dtstart>
>     <c:component>
>       <c:Vevent>
>         <c:url rdf:resource="http://www.web2con.com/"/>
>         <c:summary xml:lang="en">Web 2.0 Conference</c:summary>
>         <c:location xml:lang="en">Argent Hotel, San Francisco, CA</c:location>
>       </c:Vevent>
>     </c:component>
>     <dtend xml:lang="en">2007-10-20</dtend>
>     <c:prodid>-//connolly.w3.org//RDF Calendar $Date: 2007/06/30 19:05:32 $ (BETA)//EN</c:prodid>
>     <c:version>2.0</c:version>
>   </c:Vcalendar>
> </rdf:RDF>
So really there is no need for the BBC to adopt all out RDFa, just 
mark-up the useful  bits in RDFa,  I think its interesting that Fabiens 
XSLT resolves prefix-less values to http://www.w3.org/1999/xhtml/vocab# 
, this is good I think because at least it tries to add triples to the 
graph., but it could be resolved further by changing  the XSLT style 
sheet at http://www.w3.org/2002/12/cal/glean-hcal.xsl, to look for 
@property and @content, when determining the values of dtend and 
dtstart. I can do this Quite happily. I don't think it would be 
difficult after that to persuade the Author of X2V Brian suda to update 
his style-sheets to look for @property and @content too. Every one is in 
a WIN WIN situation after that.

[more stuff......]
> RDFa has more power and expressivity, is the same difference between
> Lego and normal-games. With Lego you can build and play anything, with
> other games you can use it only for the purpose which are created..
> not only if you have a Lego car and a Lego ship you can create a
> spaceship!

Wonderful Quote! :-)

[more stuff......]
> So, IMHO, SEO and Web Marketing can take a lof of advantages (not
> using Black or Gray Hat tactics) with Semantic Web and in particular
> with RDFa, I'm prepairing for a conference for October on this
> arguments and I'm finding a lot of positive things, but we must think
> "out of the box"
I do think "out of the Box" all the time. that part of MY problem ;-) .
> Best Wishes,
> Simone

Best Wishes

Martin McEvoy
Received on Sunday, 14 September 2008 17:21:12 UTC

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