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Re: Some RDFa 1.1 Core edge cases that we need to clarify

From: Toby Inkster <tai@g5n.co.uk>
Date: Mon, 25 Oct 2010 16:45:59 +0100
Cc: Martin McEvoy <martin@weborganics.co.uk>, public-rdfa-wg@w3.org
Message-ID: <20101025164559.5016b0a5@miranda.g5n.co.uk>
On Mon, 25 Oct 2010 13:15:44 +0100
Martin McEvoy <martin@weborganics.co.uk> wrote:

> The second vocab attribute "2#" would resolve to
> http://example.com/base2#which may be wrong?

No, that's not how base works. Check this in a browser:

<html>
 <base href="http://example.com/base">
 <a href="2#">hover over this link, look at status bar</a>
</html>

> I think @vocab should always be an absolute URI (easier to parse an
> less complicated) 

We already need to support relative links in @about, @resource, @src
and @href, so supporting relative URIs in @vocab is not too much to ask
from a parser.

Actually, re-reading the RDFa Core 1.1 spec, it seems we already allow
@vocab to be relative (or at least we don't seem to forbid it
anywhere). If so, then it seems my concerns are unwarranted, and
vocab="2#" is well-defined.

> I would Imagine that your second example would be dropped from the
> graph because RDFa is case sensitive and you haven't included the
> uppercase values in the profile, AGENT, agent and Agent are not the
> same in the RDF world.

Not so: profile terms are checked case-sensitively, falling back to a
case-insensitive check. The URIs they expand to are of course
case-sensitive. The case was similar under RDFa 1.0 too: rel="next",
rel="NEXT" and rel="nExT" each were expanded to the case-sensitive URI
<http://www.w3.org/1999/xhtml/vocab#next>.

The problem here is that "AGENT" doesn't match either "Agent" or "agent"
case-sensitively, and when the fallback match is attempted, it matches
both equally.

-- 
Toby A Inkster
<mailto:mail@tobyinkster.co.uk>
<http://tobyinkster.co.uk>
Received on Monday, 25 October 2010 15:46:29 UTC

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