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Re: comment on the syntax document: discrepancies between tests and the latest version...

From: Mark Birbeck <mark.birbeck@formsPlayer.com>
Date: Thu, 31 Jan 2008 11:21:39 +0000
Message-ID: <a707f8300801310321y445b69a0u4379d996307ef6ba@mail.gmail.com>
To: "Ivan Herman" <ivan@w3.org>
Cc: "W3C RDFa task force" <public-rdf-in-xhtml-tf@w3.org>, "Hausenblas, Michael" <michael.hausenblas@joanneum.at>

Hi Ivan,

> I try to run my newest version of tests against crazy ivan, and I get
> four failed tests. As far as I can see, all four are based on some
> discrepancies between the syntax document and the test suite (or I
> misunderstood something).

Good tests...thanks.

> Here they are:
> Tests #34 (and #38 which is more or less the same)
> --------------------------------------------------
> In Test #34 we have
> <img    about="http://sw-app.org/mic.xhtml#i"
>                         rel="foaf:img"
>                         src="http://sw-app.org/img/mic_2007_01.jpg"
>                         alt="A photo depicting Michael" />
> and the requested triple is
> <http://sw-app.org/mic.xhtml#i> <http://xmlns.com/foaf/0.1/img>
> <http://sw-app.org/img/mic_2007_01.jpg>
> The current syntax document, however, uses @src as setting the subject,
> not the object. I know this was one of our evergreen discussion... what
> is it now?

Yep...@src sets the subject. So this example wouldn't actually create
any triples, but it would create a hanging @rel (although nothing
could make use of it).

We should probably tweak the test to this:

  <div about="http://sw-app.org/mic.xhtml#i" rel="foaf:img">
    <img src="http://sw-app.org/img/mic_2007_01.jpg"
      alt="A photo depicting Michael" />

or this:

      rev="foaf:img" resource="http://sw-app.org/mic.xhtml#i"
    alt="A photo depicting Michael" />

(Or perhaps both.)

Note that the big deal about using @src as a subject rather than an
object when @rel/@rev is present is first, that you can set the type:

      rev="foaf:img" resource="http://sw-app.org/mic.xhtml#i"
    alt="A photo depicting Michael" />

and second, you can make two statements about the image in one go:

  <div about="http://sw-app.org/mic.xhtml#i" rel="foaf:img">
    <img src="http://sw-app.org/img/mic_2007_01.jpg"
        rel="license" resource="http://creative...by-sa/2.5/"
      alt="A photo depicting Michael" />

There is no way to do this if @src is used as an object.

> Test #63
> --------
> What is the latest agreement on what the value of ":next" should be? It
> is not clear (to me) in the text. The test suggests that ":next" should
> be in the xhtml vocab space, but my fear is that this may be a previous
> version of our status (ie, the test should be changed)
> My understanding is that ":next" has an empty prefix, which should be
> the base URI...

Ok...we now have two-steps to the logic, and I apologise if the spec
is not clear. The first step is that @rel is defined as follows:

  linktype ::= 'next' | 'prev' | ...
  rel ::= (linktype | curie)*

The processing rules say that the link type maps directly to a
URI...in other words, it has absolutely nothing to do with CURIEs.
This is 'logical', because that is exactly what we do with @about:

  about ::= URI | safe_curie

I.e., if @about holds a URI it is also nothing to do with CURIE processing.

So that takes care of @rel values that are valid link types. The
second step of our 'two-step logic' is that CURIEs with no prefix are
simply ignored. Note that the 'blank prefix' is a valid prefix, so
what this essentially means is that CURIEs with no colon in are

In other words, it's the second step that prevents values like
@rel="foo" from generating a triple.

In all of this, the default prefix is set to the XHTML vocabulary URI.
So @rel=":next" would be equivalent to @rel="next".

> Test #66:
> ---------
>   <head instanceof="foaf:Document">
>        <title>Test 0066</title>
>     </head>
>     <body>
>        <p>This is test #66.</p>
>     </body>
> The test suggests that
> <http://www.w3.org/2006/07/SWD/RDFa/testsuite/xhtml1-testcases/0066.xhtml>
> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
> <http://xmlns.com/foaf/0.1/Document>
> ie, there is an implicit extra about on the <head>. I know we discussed
> this, we more or less agreed on that, but it is not on the syntax
> document as far as I can see...

I think you are right...my apologies again.



  Mark Birbeck

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Received on Thursday, 31 January 2008 11:21:56 UTC

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