- From: Graham Klyne <gk@ninebynine.org>
- Date: Fri, 25 Jul 2003 13:13:56 +0100
- To: Frank Manola <fmanola@mitre.org>
- Cc: rdf core <w3c-rdfcore-wg@w3.org>
Frank, I'm happy for you to make the call on all of these points. I don't really understand the full C14N issues here, but your suggestion looks to me like an improvement. #g -- At 08:05 25/07/03 -0400, Frank Manola wrote: >Graham Klyne wrote: > >>This looks good to me. One tiny nit and one small comment: >>Nit: The use of "third" in "using a third value of the rdf:parseType >>attribute" seemed a little odd to me. Maybe just: 'using the attribute >>rdf:parseType="literal"'? > > >This may look odd because you don't have the context. Four paragraphs >before, in the prior section (on rdf:value), I describe "the second use" >of rdf:parseType, rdf:parseType="Resource". Two sections before that, the >section on Collections introduces rdf:parseType (and notes that it has >multiple values), in the process of introducing the first use, >rdf:parseType="Collection". Mentioning the third use was just to gently >point out that this was something the reader had seen variants of before. > > >>Comment: it might help to underscore somehow that using >>rdf:parseType="literal" doesn't require that the data contain markup. >>This is implicit and clear to one who has followed this discussion, but >>I'm not sure how clear that would be to someone coming fresh to this text. >>For example, may the sentence: >>[[ >>The value of the property is a typed literal, whose datatype, >>rdf:XMLLiteral, is defined in [RDF-CONCEPTS] specifically to represent >>fragments of XML. >>]] >>might be: >>[[ >>The value of the property is a typed literal, whose datatype, >>rdf:XMLLiteral, is defined in [RDF-CONCEPTS] specifically to represent >>fragments of XML, including character sequences that may or may not >>include XML markup. >>]] > > >I agree; this is a useful clarification. > >On another issue, since we're clarifying things: in the text below, in >discussing exclusive canonicalization, the text says: > >"This causes declarations of used namspaces to be added to the fragment..." > >I wonder if this wouldn't be clearer if it said: > >"This causes declarations of *namespaces used in the fragment* to be added >to the fragment..." > >to distinguish namespaces used in the RDF/XML in general from those >explicitly used in the fragment. > >--Frank > > >>-- >>At 15:05 24/07/03 -0400, Frank Manola wrote: >> >>>Based on Brian's last "take", I propose to put the following text in the >>>Primer for parseType="Literal". The typed literal given for the value >>>of <dc:title> in the triple is that produced by the RDF Validation >>>Service, but someone may want to check this further anyway. >>> >>>4.5 XML Literals >>> >>>Sometimes the value of a property needs to be a fragment of XML, or text >>>that might contain XML markup. For example, a publisher might maintain >>>RDF metadata that includes the titles of books and articles. >>>While such titles are often just simple strings of characters, this is >>>not always the case. For instance, the titles of books on mathematics >>>may contain mathematical formulas that could be represented using MathML >>>[MATHML]. Titles might also include markup for other reasons, such as >>>for Ruby annotations [RUBY], or for bidirectional rendering or special >>>glyph variants (see, e.g., [CHARMOD]). >>> >>>RDF/XML provides a special notation to make it easy to write literals of >>>this kind. This is done using a third value of the rdf:parseType >>>attribute. Giving an element the attribute rdf:parseType="Literal" >>>indicates that the contents of the element are to be interpreted as an >>>XML fragment. Example 22 illustrates the use of rdf:parseType="Literal": >>> >>><?xml version="1.0"?> >>><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" >>> xmlns:dc="http://purl.org/dc/elements/1.1/" >>> xml:base="http://www.example.com/books"> >>> >>> <rdf:Description rdf:ID="book12345"> >>> <dc:title rdf:parseType="Literal"> >>> <span xml:lang="en"> >>> The <em><br /></em> Element Considered Harmful. >>> </span> >>> </dc:title> >>> </rdf:Description> >>> >>></rdf:RDF> >>> >>>The RDF/XML in Example 22 describes a graph containing one triple: >>> >>>ex:book12345 <dc:title> "<span xml:lang="en"> The <em><br >>>/></em> Element Considered Harmful. </span>"^^rdf:XMLLiteral . >>> >>>The rdf:parseType="Literal" attribute in the RDF/XML indicates that all >>>the XML within the <dc:title> element is an XML fragment that is the >>>value of the dc:title property. >>> >>>The value of the property is a typed literal, whose datatype, >>>rdf:XMLLiteral, is defined in [RDF-CONCEPTS] specifically to represent >>>fragments of XML. The XML fragment is canonicalized according to the >>>XML Exclusive Canonicalization recommendation [XML-XC14N]. This causes >>>declarations of used namespaces to be added to the fragment, the >>>escaping of reserved characters such as '<', '>' and '&', and possibly, >>>the re-ordering of attributes. Contextual attributes, such as xml:lang >>>and xml:base are not inherited from the RDF/XML document, and, if >>>required, must, as shown in the example, be explicitly specified in the >>>XML fragment. >>> >>>This example illustrates that care must be taken designing RDF data. >>>It might appear at first glance that titles are simple strings best >>>represented as plain literals, and only later might it be discovered >>>that some titles contain markup. In cases where the value of a property may >>>sometimes contain markup and sometimes not, either >>>rdf:parseType="Literal" should be used throughout, or software must >>>handle both plain literals and rdf:XMLLiterals as values of this property. >>> >>>@@Informational References to be added: >>> >>>[RUBY] Ruby Annotations, Sawicki, M., Suignard, M., Ishikawa, M., Durst, >>>M., Texin, T., World Wide Web Consortium, 31 May 2001. This version is >>>http://www.w3.org/TR/2001/REC-ruby-20010531/. The latest version is >>>http://www.w3.org/TR/ruby/. >>> >>>[XML-XC14N] @@use citation in Syntax >>> >>>[CHARMOD] @@use citation in Syntax >>> >>>[MATHML] Mathematical Markup Language (MathML) Version 2.0, Carlisle, >>>D., Ion, P., Miner, R., Poppelier, N. (Editors); Ausbrooks, R., Buswell, >>>S., Dalmas, S., Devitt, S., Diaz, A., Hunter, R., Smith, B., Soiffer, >>>N., Sutor, R., Watt, S. (Principal Authors), World Wide Web Consortium, >>>21 February 2001. This version is >>>http://www.w3.org/TR/2001/REC-MathML2-20010221. The latest version is >>>http://www.w3.org/TR/MathML2. >>> >>> >>> >>> >>>-- >>>Frank Manola The MITRE Corporation >>>202 Burlington Road, MS A345 Bedford, MA 01730-1420 >>>mailto:fmanola@mitre.org voice: 781-271-8147 FAX: 781-271-875 >> >>------------------- >>Graham Klyne >><GK@NineByNine.org> >>PGP: 0FAA 69FF C083 000B A2E9 A131 01B9 1C7A DBCA CB5E > > >-- >Frank Manola The MITRE Corporation >202 Burlington Road, MS A345 Bedford, MA 01730-1420 >mailto:fmanola@mitre.org voice: 781-271-8147 FAX: 781-271-875 ------------------- Graham Klyne <GK@NineByNine.org> PGP: 0FAA 69FF C083 000B A2E9 A131 01B9 1C7A DBCA CB5E
Received on Friday, 25 July 2003 08:45:21 UTC