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Re: [RDFa] rdf:XMLLiteral (was RE: Missing issue on the list: identification of RDFa content)

From: Ian Davis <iand@internetalchemy.org>
Date: Mon, 19 Mar 2007 08:47:44 +0000
Message-ID: <45FE4E30.4090204@internetalchemy.org>
To: mark.birbeck@x-port.net
CC: public-rdf-in-xhtml-tf@w3.org

On 19/03/2007 02:51, Mark Birbeck wrote:
> The only way to encode this *exactly* would be to do this:
> 
>  <span property="dc:title" content="RDF or Bust" />
> 
> However, I would suggest that in this discussion we have to keep
> reminding ourselves that we are dealing with XHTML that contains RDF,
> and *not* with RDF. So, to illustrate why this is significant, take
> the fact that best practice in XHTML is to have a default language at
> the root of the document. Your example might now look like this:
> 
>  <html xmlns="..." lang="en" xml:lang="en">
>    ...
>    <body>
>      <span property="dc:title" content="RDF or Bust" />
>    </body>
>  </html>
> 
> But the addition of the language attribute means that your triple
> immediately becomes this:
> 
>  <http://example.com/doc> dc:title "RDF or Bust"@en .

Needless to say this argument is completely bogus. Using the language 
attributes as you suggest is clearly the author's intent. If they wanted 
to encode a triple without the language, then they'd omit the language 
attribute.

Either way, RDFa currently provides no way of encoding a triple with a 
plain literal value using the text that the author has marked up. 
Currently it requires duplication of the text in a content attribute. 
This is a serious flaw.

[snip]

> So, all I did when trying to address this problem originally was ask,
> what is so bad about the following triple being used instead:
> 
>  <http://example.com/doc> dc:title "RDF or Bust"^^rdf:XMLLiteral .

So, perhaps this is the flaw in your logic that you're asking us to 
find. This is completely incompatible with having a language on the root 
element since "RDF or Bust"^^rdf:XMLLiteral is a typed literal which may 
not have a language.

> Although it's not perfect, I found after a lot of research that there
> isn't as much wrong with it as one might initially think, and I've
> still not heard of another way to solve all of the issues and remain
> consistent with our design goals.

There is a lot wrong with it. Your technical argument ignores the social 
aspect entirely. Did you survey how people are using RDF instance data 
to determine whether people prefer to use plain or XML literals? If so, 
can you provide a URI so I can see the results.

Ian
Received on Monday, 19 March 2007 08:48:05 GMT

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