- From: Doug Schepers <schepers@w3.org>
- Date: Thu, 09 Oct 2008 23:39:19 -0400
- To: Manu Sporny <msporny@digitalbazaar.com>
- CC: SVG WG <www-svg@w3.org>, RDFa mailing list <public-rdf-in-xhtml-tf@w3.org>
Hi, Manu- Thanks for your comments. We have put them in our tracker as ISSUE-2097. We will discuss your comments and get back to you promptly. Regards- -Doug Manu Sporny wrote (on 10/9/08 11:06 PM): > The following are official comments from the RDF in XHTML Task Force > related to the latest SVG Tiny Working Draft located here: > > http://www.w3.org/TR/SVGMobile12/metadata.html#MetadataAttributes > > The comments revolve around the re-use of RDFa attributes in SVG, which > we are very pleased to see, but feel that there should be specific > direction on how those attributes are used. > > Re-use of RDFa attributes should follow RDF in XHTML processing rules > --------------------------------------------------------------------- > > http://www.w3.org/TR/SVGMobile12/metadata.html#MetadataAttributes > """ > SVG includes several attributes that may be placed on any element, for > the use of attribute-based metadata formats. These include the 'class', > 'role', 'rel', 'rev', 'about', 'content', 'datatype', 'property', > 'resource', and 'typeof' attributes. ***SVG makes no specific > requirements about the values for these attributes, other than their > particular value data types, such as a string or a space-separated lists > of strings.*** Other specifications, such as RDFa [RDFA], Microformats > [MF] patterns, or ARIA [ARIA] ontologies, > """ > > The current text leaves far too much room for mis-use and abuse of the > RDFa attributes. It would be a shame if authors were allowed to > re-define how a non-RDFa parser may use those attributes in such a way > as to directly conflict, or even worse, create ambiguity with regard to > the current RDF in XHTML parser rules. The RDFa task force went to great > lengths to ensure that the RDFa Syntax Processing[1] rules define clear > behavior when RDFa is used in non-XHTML languages. > > Please add text clearly stating that if one re-uses the RDFa attributes > that they follow the same processing rules as outlined in the RDFa > Syntax Processing Rules[1]. > > @rel/@rev values do not necessarily need to be prefixed > ------------------------------------------------------- > > http://www.w3.org/TR/SVGMobile12/metadata.html#MetadataAttributes > """ > When used with RDFa, the values for the 'rel' and 'rev' attributes must > be a CURIE [RDFA] (i.e., a prefixed string, such as 'cc:license' to > indicate a Creative Commons license), while the values may simply be > from a set of specific keywords for Microformats. These formats may be > used independently, or in combination if the keywords do not clash. > """ > > The @rel/@rev values in RDFa can either be a reserved word or a CURIE as > defined in the RDFa Syntax document[2]. Perhaps the SVG Tiny document is > authored to not support reserved words due to a mis-reading or > mis-understanding of the current CURIE specification[3]? The current > specification allows both prefixed and unprefixed "reference only" values: > > http://www.w3.org/TR/curie/#s_syntax > """ > curie := [ [ prefix ] ':' ] reference > ... > A host language MAY interpret a reference value that is not preceded by > a prefix and a colon as being a member of a host-language defined set of > reserved values. Such reserved values MUST translate into an IRI, just > as with any other CURIE. > """ > > We urge the SVG WG to not limit CURIEs and provide a CURIE mechanism as > defined by the CURIE specification. It would make the job of RDFa parser > authors much easier as there are less special cases to consider when > creating their parser. The current language in SVG Tiny requires all > current RDFa parsers to strip out all reserved word processing in order > to conform to SVG+RDFa, which would lead to two increasingly divergent > types of RDFa parsers: > > 1. Parsers that parse SVG+RDFa 1.0. > 2. Parsers that parse "XHTML+RDFa 1.0". > > The SVG Tiny document seems to insist that terms must be of the form > "x:y", instead of also allowing things like "license" (note that there > isn't a preceding colon before a reserved word). > > We are currently working on a method to specify reserved words that will > not need preceding colons and the current language in SVG Tiny would > prevent that method from being used in SVG Tiny. > > Please do one of the following: > > * Adopt the current RDFa/CURIE processing rules as-is. > * Define a set of reserved words that should be used in SVG Tiny and > preserve the functionality provided in the CURIE Specification. > * Do not rule out the ability to use non-colon-prefixed reserved words. > > @role should follow rules defined in XHTML 1.1 Role Module > ------------------------------------------------------------ > > This is not an official comment from the RDF in XHTML Task Force and > will probably be mentioned by the XHTML WG. Mark, Shane and Steven were > on todays RDFa telecon and had issues with the lack of specifics as to > how an author could use @role. Just a heads up that they would like to > see it clearly stated that use of @role should follow the specifics > outlined in the XHTML Role Attribute Module[4]. We want to make sure > that authors are not under the false assumption that they can put > whatever they want to in the @role attribute. > > Thanks to the SVG WG in advance for consideration of these issues. We > are looking forward to using RDFa-based semantics in SVG Tiny. Keep up > the great work! :) > > -- manu > > [1] http://www.w3.org/TR/rdfa-syntax/#sec_5.5. > [2] http://www.w3.org/TR/rdfa-syntax/#relValues > [3] http://www.w3.org/TR/curie/ > [4] http://www.w3.org/TR/xhtml-role/ >
Received on Friday, 10 October 2008 03:39:28 UTC