meeting record: 2005-11-22 RDF-in-XHTML TF telecon

The minutes of yesterday's telecon [1] are now available for review.
A text snapshot of Revision 1.2  2005/11/23 14:25:38 follows.

   [1] http://www.w3.org/2005/11/22-swbp-minutes

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SWBPD RDF-in-HTML TF

22 Nov 2005

   [2]Agenda

      [2] http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2005Nov/0025.html

   See also: [3]IRC log

      [3] http://www.w3.org/2005/11/22-swbp-irc

Attendees

   Present
          Ben Adida, Ralph Swick, Jeremy Carroll

   Regrets
          Mark, Steven

   Chair
          Ben

   Scribe
          Ralph

   Previous
          [4]2005-11-15

      [4] http://www.w3.org/2005/11/15-swbp-minutes

Contents

     * Topics
         1. issue 13. Plain Literals
         2. issue 9. Making link content clickable
     * Summary of Action Items

     _________________________________________________________________


Issue 13. Plain Literals

   -> [9]Mark's comments

      [9] http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2005Nov/0031.html

   <benadida> [10]issues list

     [10] http://www.w3.org/2001/sw/BestPractices/HTML/2005-current-issues

   Ralph: do you have a use case for plain literals?

   Ben: Jeremy suggested this; he implied it had been done before

   <benadida> point 8 in "[11]Comments on RDF/A spec"

     [11] http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2005Oct/0057.html

   -> [12]Plain Literals in RDF Concepts

     [12] http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#dfn-plain-literal

   Ben: this feature allows you to avoid some data duplication

   Ralph: do we have a strong requirement for plain literals -- the
   concatenation example in the issues list?

   Jeremy: the goal was to have inline content just once and many RDF
   Schemas would expect this text to be a plain literal. Plain literals
   would be more natural to the RDF Community than XML literals

   Ben: the idea of concatenating the content of the child elements also
   appears in Ian Davis' Embeddable RDF proposal

   Jeremy: it's appealing to invent a pseudo-datatype in our syntax but
   it would have special syntactic rules. Special rules would be annoying
   from an implementation point of view

   Ben: it feels to me like a small enough impact on the syntax to be
   worth the positive result. see 5.1.2.1 in RDF/A syntax

   -> [13]5.1.2.1 Literal from string value of meta

     [13] http://www.w3.org/2001/sw/BestPractices/HTML/2005-rdfa-syntax#id0x056eca88

   Ben: if 5.1.2.1 stays then we'd have to add a special datatype to make
   plain literals

   Jeremy: the complication of a special datatype is that plain literals
   are not a datatype. A second complication related to xml:lang. In
   5.1.2.1 if there were an xml:lang attribute it would be discarded as
   typed literals do not have language information. It becomes
   horrendously complicated in 5.1.2.1 if we add plain literal support
   and there are multiple xml:lang attributes; we'd likely need to
   specify that xml:lang must be discarded if there is contradictory data

   Ralph: language handling in literals was a very contentious issue for
   internationalization. We should approach this area with caution

   Jeremy: xsd:string does not contain language information. In an XHTML
   document we have textual data that is natural language data and may be
   marked up with language information. If in the process of constructing
   metadata from this -- converting from the presentation format to the
   RDF format -- we lose language information in a way that is cavalier,
   I would expect the I18N people to complain. I don't think it is
   cavalier to discard language information on data that is explicitly
   typed; e.g. when explicitly datatyped as datatype="xsd:string". If we
   have a plain literal pseudo-datatype then it would be cavalier to
   discard language information, so I think plain literals should behave
   differently from typed literals even though the syntax is similar.
   XHTML2 is intended to be a means to transport natural language text so
   it may be more important to preserve language information in XHTML2
   literals than in XML literals

   Ben: so issue 13 is really just a plain literal issue and I've been
   generalizing it

   Jeremy: the issue list should include discussion of discarding
   xml:lang

   ACTION: Ben update issues list to add discarding of xml:lang
   information
   [recorded in http://www.w3.org/2005/11/22-swbp-minutes.html#action01]

   Jeremy: xml:lang attributes on child elements that contradict xml:lang
   on the parent create a problem; we'll have to make an arbitrary
   choice. Whatever choice we make isn't likely to cause much fuss

   Ben: what problems would we introduce if we defined a pseudo-type?

   Jeremy: confusion if someone attempted to use that pseudo-type in
   RDF/XML

   Ralph: I'd like to see a use case for this. consider the following
   RDF/XML and RDF/A examples, which should generate the same value type:

   <dc:title><b>This</b> is a book</dc:title>

   <meta property="dc:title"><b>This</b> is a book</meta>

   Jeremy: in terms of document size, specifying the pseudo-type will be
   just as much space as repeating the text
   ... different argument is that RDF tools should support natural
   language information expressed in XHTML2 documents

   <benadida> <meta xml:lang="en" property="dc:title"><b>This</b> is a
   book</meta>

   Jeremy: xml:lang attribute on meta would be ignored under current
   RDF/A syntax spec but an xml:lang on <b> should be preserved. The XML
   literal is required to be canonicalized via the XML exclusive
   canonicalization algorithm

   Ben: seems to be an oversight if xml:lang on the element containing a
   property attribute is ignored

   Jeremy: not an oversight; there's no place to put this language
   information. Consider the example in issue 13; the XML literal has 4
   children; two element nodes and two text nodes. On the element nodes
   we can hang language information but we'd have to invent some new node
   type to hang language on the text. The decision to drop xml:lang
   information was contentious in the RDF Core WG but the resolution
   relied on saying that with an RDF/XML document, RDF could specify the
   handling of xml:lang. This resolution would not carry over to an XHTML
   document. During RDF Core deliberations I proposed a design in which
   XML literals had a wrapper node but that design was rejected by the WG

   Ralph: yeah, we need to treat XHTML document content with more respect

   Jeremy: I prefer the option of adding spans

   Jeremy proposed that option in point 7 of [15]Comments on RDF/A spec]

     [15] http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2005Oct/0057.html

   Jeremy: it would be a bad thing to encourage RDF apps to use just
   xsd:string. When extracting metadata from XHTML2, we should encourage
   preservation of language information

   Ben: so tentatively we'll say 'no' to issue 13


issue 9. Making link content clickable

   Ben: I'd like to make this kind of link element clickable. Mark agreed
   but proposed some additions

   Ralph: seems reasonable but I would leave this to the HTML WG to
   decide; it feels out of scope for this task force.
   I would not want to strongly advocate either way from an RDF
   perspective; you're asking for behavior from XHTML2 processors

   Ben: do we see any complications?

   Ralph: making link act a lot like anchors? I can't see a complication
   but I've never written a browser

   Jeremy: in XHTML2 anchor is more superfluous; it's the presence of
   href that matters

   Ben: if the Task Force does not express an opinon we give up one of
   our requirements. In the current XHTML2 syntax the example in issue 9
   does not make a clickable link. This example is something we might
   want to express

   Ralph: regrets if we meet next week (29 Nov)

   Jeremy: I expect to be available on the 29th

Summary of Action Items

   [NEW] ACTION: Ben update issues list to add discarding of xml:lang
   information
   [recorded in http://www.w3.org/2005/11/22-swbp-minutes.html#action01]

   [PENDING] ACTION: Mark investigate authoritative specifications for
   '[' as a URI character
   [recorded in http://www.w3.org/2005/11/15-swbp-minutes.html#action01]

   [PENDING] ACTION: Mark report on the status of src attribute
   definition
   [recorded in http://www.w3.org/2005/10/25-swbp-minutes.html#action02]

   [PENDING] ACTION: Steven track and report on Role discussion before
   next Tuesday
   [recorded in http://www.w3.org/2005/10/18-swbp-minutes.html#action05]

   [PENDING] ACTION: Ben to put together the "ACID" test for XHTML2 RDF/A
   [recorded in http://www.w3.org/2005/07/26-swbp-minutes.html#action02]

   [PENDING] ACTION: Mark and Ben to check edge cases of inheritance in
   RDF/A
   [recorded in http://www.w3.org/2005/07/26-swbp-minutes.html#action06]

   [PENDING] ACTION: Ralph and Ben to augment the issues list
   [recorded in http://www.w3.org/2005/09/27-swbp-irc#T14-30-04]

   [End of minutes]

   Change Log:
$Log: 22-swbp-minutes.html,v $
Revision 1.2  2005/11/23 14:25:38  swick
Cleanup for publication

     _____________________________________________________________

    $Date: 2005/11/23 14:25:38 $

Received on Wednesday, 23 November 2005 14:36:43 UTC