- From: Alex Milowski <alex@milowski.com>
- Date: Fri, 31 May 2013 10:10:25 -0700
- To: W3C RDFWA WG <public-rdfa-wg@w3.org>
- Message-ID: <CABp3FNK7V7nEGP8PUfeJ-9-Vw4=VDWjDFDVPDuSm-Y-ZN2zB0g@mail.gmail.com>
I dug into this a bit and essentially, as Peter points out, the "lang" property on any element node in the DOM is mostly useless for determining the language of a node. The language is defined in HTML5 as the nearest ancestor with an lang/xml:lang attribute [1]. If there is no such ancestor, the "pragma-set default language" is used (i.e. the "meta" element with http-equiv="content-language"). ...and then there is this document [3] that says the "meta" element should not be used. I think it would be good idea, as a future option, to allow the language to set in the initial context. This would allow processors to property pick up the Content-Language header from the environment. This would require a change to section 7.2. It would also be a quality of implementation detail because the Content-Language isn't necessarily exposed in a standard way in all environments (e.g. the browser vs. otherwise). The good news is that the algorithm will correctly calculate the language for an element in a HTML document as specified as long as the user does not use the meta element or expect the Content-Language header to set the default. Those are somewhat big caveats for random HTML "in the wild" but not necessarily a show-stopper for people publishing new documents using RDFa. That is, the recommended path forward is to use lang/xml:lang attributes as appropriate. [1] http://www.w3.org/TR/html5/dom.html#the-lang-and-xml:lang-attributes [2] http://www.w3.org/TR/html5/document-metadata.html#pragma-set-default-language [3] http://www.w3.org/International/questions/qa-html-language-declarations On Fri, May 31, 2013 at 2:58 AM, Ivan Herman <ivan@w3.org> wrote: > It was discussed yesterday on the call and this is certainly the general > direction. Manu will check with the HTML5 experts on what happens in the > DOM... > > Thanks > > Ivan > > Peter Occil wrote: > > Your suggestion would be fine by me if it's accepted by the working > group. > > > > --Peter > > > > -----Original Message----- From: Ivan Herman > > Sent: Thursday, May 30, 2013 9:34 AM > > To: Peter Occil > > Cc: public-rdfa-wg@w3.org > > Subject: Re: Language of a node and HTML+RDFa JavaScript implementations > > > > Peter, > > > > I *think* I understand the issue and, coincidentally, we will have a > call in a > > half an hour where this issue may be discussed. Again as an individual, I > > believe that the only way we can handle that in RDFa is that the > generated RDF > > uses whatever the markup gives us (which indeed means that the current > section > > 3.3. may not be precise enough). Ie, to use the example below, in the > case of > > Document 4: > > > > <html><p>Document 4</p></html> > > > > the generated RDF literal will _not_ include a language tag. Actually, > that > > would be the case for > > > > <html><meta http-equiv="content-language" > content="en"><p>Document>3</p></html> > > > > because RDFa tries to be language neutral. AFAIK, all current RDFa > processors > > work this way. > > > > I think the important point is that RDF makes a difference between plain > > literals and literals with language tags. Ie, the generated RDF from > RDFa has > > the freedom to generate a plain literal if no language tag has been > assigned. > > > > Thanks! > > > > Ivan > > > > -- > Ivan Herman, W3C > Semantic Web Activity Lead > Home: http://www.w3.org/People/Ivan/ > mobile: +31-641044153 > http://www.ivan-herman.net/foaf#me > -- --Alex Milowski "The excellence of grammar as a guide is proportional to the paucity of the inflexions, i.e. to the degree of analysis effected by the language considered." Bertrand Russell in a footnote of Principles of Mathematics
Received on Friday, 31 May 2013 17:10:52 UTC