Re: XML:Base - impact on RDF (first pass)

Dan Brickley wrote:

> I've become more sympathetic to this view over the week, and feel I
> may have been over enthusiastic for adding xml:base support during last
> week's call. That said, I remain very concerned about the deployment
> implications should we say that the interaction of xml:base and rdf:RDF
> be 'undefined', specifically in mixed-namespace XML documents. The M&S
> syntax defines some XML structures that can be used either stand-alone
> (with RDF:RDF as the root XML element), or else as part of a larger
> mixed-namespace document (eg. in HTML/XHTML). In the latter scenario, the
> RDF  syntax specification has to play well with other specs (which may want to
> or need to use xml:base; XML Protocols for eg. come to mind...).
> 
> In this situation, I wonder if we might explore the idea of revising our
> syntax spec so that it distinguishes more clearly between (i) "pure RDF"
> XML documents and (ii) "mixed in" documents that include RDF. The former
> we have complete control over; the latter are composed according to two or
> more specs. I would be happy outlawing xml:base for (i), but in the
> context of (ii) we have to accept that xml:base is likely to be used:
> these things are beyond our control. TimBL has also (@@ref) previously
> raised the need for more clarity regarding the meaning of an XML document
> that embeds RDF down inside some other XML elements (eg: in html/head or
> html/body/quoted...), so there may be other reasons for sharpening this
> distinction.
> 
> If we simply say "don't use xml:base" this could be taken as implicitly
> telling implementors never to use RDF in a mixed-namespace context since
> its interaction with other namespaces in the same doc is undefined. If the
> latter is what we mean, I'd like to say that explicitly...
> 
> Dan
> 

Agreed.

I think this was the meaning of my garbled comments during the conf call
a couple of weeks back. Surely, XML:Base will come at us as part of the
underlying XML base even though we can argue against recommending it for
stand-alone RDF. I wouldn't vote for the last option if it denies
embedding in a `mixed-namespace context'. We do need to recognize those
things which are `beyond our control'.

-- 
Martyn Horner <martyn.horner@profium.com>
Profium (former name Pro Solutions), Les Espaces de Sophia,
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Received on Thursday, 14 June 2001 05:50:38 UTC