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Re: Please declare in GRDDL spec that XML validation is not required

From: Dan Connolly <connolly@w3.org>
Date: Sat, 10 Feb 2007 01:17:27 -0600
To: Dave Beckett <dave@dajobe.org>
Cc: public-grddl-comments@w3.org
Message-Id: <1171091847.7497.802.camel@dirk>

On Fri, 2007-02-09 at 22:13 -0800, Dave Beckett wrote:
> http://chatlogs.planetrdf.com/swig/2007-02-10#T03-28-23
> onwards:
> <chimezie> .grddl
> http://www.ibiblio.org/hhalpin/homepage/notes/vcardtable.html "SELECT
> ?homeSyn WHERE { ?homeSyn owl:equivalentProperty foaf:homePage }"
> <Emeka> Querying against 98 triples
> ...
> Raptor failed on this document.
> Checking I found:
> $ xmllint --valid --noout
> http://www.ibiblio.org/hhalpin/homepage/notes/vcardtable.html
> http://www.ibiblio.org/hhalpin/homepage/notes/vcardtable.html:29: element
> div: validity error : ID v.Address already defined
> w3.org/2006/vcard/ns#Address">v:Address</a></td><td></td><td><div id="v.Address"
>                                                                                ^
> http://www.ibiblio.org/hhalpin/homepage/notes/vcardtable.html:48: element
> tr: validity error : Element tr content does not follow the DTD, expecting
> (th | td)+, got (td td a td td )
> </tr><tr id="v.url">
>      ^
> http://www.ibiblio.org/hhalpin/homepage/notes/vcardtable.html:134: element
> tr: validity error : ID v.role already defined
> </tr><tr id="v.role">
> However GRDDL.py was generating triples.   It was not obvious to me
> that you are assuming the GRDDL process runs in WF-only XML mode.
> I shall change Raptor's use of libxml accordingly, if this is
> the case.

Let's see... I think the WG did consider a relevant issue

what infoset to use as the input to GRDDL transformations? do XInclude?

Perhaps the resolution we came up with addresses your request?

"This specification is purposely silent on the question of which XML
processors are employed by or for GRDDL-aware agents. Whether or not
processing of XInclude, XML Validity, XML Schema Validity, XML
Signatures or XML Decryption take place is implementation-defined.
... "
 http://www.w3.org/2004/01/rdxh/spec#issue-faithful-infoset 1.206

(I argued for a more conservative resolution to the issue, but

> Is XML validation of the profile/namespace URIs, XSLT documents
> also ignored?  I would assume not, since they are somebody else's
> mime type, spec.  

The spec defines GRDDL results without using
terms like "ignored"; the definitions are declarative rules,
rather than specifying how implementations work. I think
an implementation that allows well-formed-but-invalid
profile and namespace documents is consistent with the spec.

> RDF/XML aka application/rdf+xml does use validation.

I don't understand what you mean by that. In what way
does RDF/XML use validation?

I suppose it would be possible to distinguish not only
valid documents from well-formed documents but als
documents with no DTD from those that have a DTD but
don't match it. So far, we haven't bothered with those
details, but only referred to XPath nodes.

I do hope we'll find time to add tests for the cases you're
asking about.

> Dave
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Saturday, 10 February 2007 07:17:38 UTC

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