- From: Henri Sivonen <hsivonen@iki.fi>
- Date: Thu, 14 May 2009 09:36:05 +0300
- To: Ben Adida <ben@adida.net>
- Cc: public-html@w3.org
On May 13, 2009, at 20:18, Ben Adida wrote: > Yes, it's important to validate theories. Henri's theory that > xmlns:foo would be impossible/difficult to parse correctly in text/ > html proved to be a fairly weak argument in practice (Google, Yahoo, > and my Firefox bookmarklet do just fine.) Please don't mischaracterize what I have said in order to dismiss it. I have said: 1) If xmlns:foo is parsed the way it's currently specced and implemented in Gecko, WebKit and Opera, a namespace-aware API representation of it is different for text/html and application/xhtml +xml DOMs. (This is not theory. It is a testable statement of fact.) If the namespace-aware representation is different for text/html and application/xhtml+xml DOMs, applications that support both need divergent code paths on the application layer to paper over the difference. Having divergent code paths is bad. (Browser-internal APIs in Gecko are in the namespace-aware category as are the Level 2 parts of DOM.) 2) Some namespace-aware representations don't allow an attribute with local name "xmlns:foo" in no namespace to be represented at all. XOM is such a representation. (It throws if you try to set such an attribute.) 3) Finding out whether it is feasible to change text/html parsing to make the data model representation of xmlns:foo match the representation parsed from application/xhtml+xml would involve shipping such an implementation, which means finding out entails non- trivial cost. (Note that I have not claimed that it would be impossible--just that the experiment has such cost characteristics that I think a microdata solution should avoid the need to perform that experiment.) Your bookmarklet doesn't refute any of the above points because it uses a namespace-unaware API (DOM Level 1). It is unclear if recent services unveiled by Google and Yahoo! refute any of my points. Do either of them support both text/html and application/xhtml+xml? If yes, is it known if they have divergent code paths internally? Is it known if they use conforming HTML and XML parsers? Furthermore, according to Hixie, Yahoo! treats prefix as meaningful (http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2009Mar/0100.html ), which is evidence *against* prefix-based indirection doing just fine. So far, I haven't seen evidence showing whether Google implements CURIEs per spec (to the extent to which there is a spec; RDFa has not been specced for text/html) or whether they, too, give meaning to the prefix. -- Henri Sivonen hsivonen@iki.fi http://hsivonen.iki.fi/
Received on Thursday, 14 May 2009 06:36:46 UTC