Re: More on the 'legacy' namespacing question

Hi Mark,

you actually pre-empted me; I just come back from the DC conference
where the issue vs RDFa came up. Having talked to the DCMI guys, here is
the standpoint of DCMI at the moment:

- in the first round, DCMI will update their document to include DC
information in the HTML header using the current 'DC.tite' scheme. That
will be done using a special profile in the header, and they will also
provide a GRDDL transform on the profile document level. Ie, if somebody
uses this approach, and a GRDDL processor, the RDF information can be
extracted using GRDDL.

However, that is clearly a mechanism in <head> only.

- once RDFa is finalized and officially published, DCMI will endorse
RDFa and propagate to use _full RDFa syntax everywhere_, with no special
requirement. Ie, xmlns for the namespaces, dc:title syntax (both in the
header and elsewhere), etc.

Ie: as far as DCMI goes (which _is_ our biggest customer for that
issue), the whole question on 'dotted' vs. 'coloumn' synstax is moot,
and we should put it on ice for our own technical discussion. I think
this is a win-win. But this also means, that we do *not* really need any
hGRDDL rules for this use case either....

This is a bit orthogonal to the @name issue that you refer to below. My
impression is that we should keep to what we decided before. The various
adaptations to different targets can still be done, after all

name="DC.title dc:title"

is also perfectly valid, isn't it? Ie, I am not sure why Bob's mechanism
 would shed any new light...

Ivan

Mark Birbeck wrote:
> Hi Ivan,
> 
> I was just reading this:
> 
>   <http://www.snee.com/bobdc.blog/2007/08/automated_rdfa_output_from_dit.html>
> 
> from Bob du Charme. In it he makes the point that it's very easy to
> change your server-side generation code from generating this:
> 
>   <meta name="DC.Title" content="My Topic" />
> 
> to generating this:
> 
>   <meta property="dc:title" content="My Topic" />
> 
> I was about to fire off an email pointing out that you can actually
> use @name as well, and then it occurred to me that perhaps we should
> actually _exclude_ @name from our processing. In other words, rather
> than being indifferent about this we would say it doesn't actually
> work:
> 
>   <meta name="dc:title" content="My Topic" />
> 
> By doing this we can keep @name 'unpolluted' with new stuff, and when
> we see it we can be sure that it contains legacy values. We therefore
> create two possible scenarios, which may prove useful.
> 
> The first is that Bob's server-side code could actually generate this, instead:
> 
>   <meta name="DC.Title" property="dc:title" content="My Topic" />
> 
> Since he is in control of what his server is generating, he might
> choose to target both RDFa parsers (with @property) and existing HTML
> processors like search-engine crawlers, with @name. This might be
> particularly useful if the <meta> property is something that a
> search-engine might make use of, but the value is something that we
> want to use in an RDFa processor, like this:
> 
>   <meta name="description" property="dc:description" content="My description" />
> 
> The second scenario is that our hGRDDL rules can be more focused--at
> least in relation to the <head> of the document. If the pre-processor
> were to detect certain values in @name, then all it has to do is add a
> 'property' attribute to the element, containing a more RDF-friendly
> value, and which will be picked up by the RDFa processor. If a
> 'property' attribute already exists then the pre-processor need do
> nothing.
> 
> By explicitly confining the 'legacy' problem to the one attribute--or
> at least a large chunk of the legacy problem--we might find this issue
> easier to manage; we'll probably find it easier to define the
> 'mapping' rules.
> 
> Any thoughts on that?
> 
> Regards,
> 
> Mark
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
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Received on Sunday, 2 September 2007 09:10:00 UTC