- From: Joe D Williams <joedwil@earthlink.net>
- Date: Mon, 1 Mar 2010 15:10:12 -0800
- To: "Maciej Stachowiak" <mjs@apple.com>
- Cc: "Henri Sivonen" <hsivonen@iki.fi>, "Leonard Rosenthol" <lrosenth@adobe.com>, "Anne van Kesteren" <annevk@opera.com>, "Larry Masinter" <LMM@acm.org>, "'Toby Inkster'" <tai@g5n.co.uk>, "'Adam Barth'" <w3c@adambarth.com>, "'HTML WG'" <public-html@w3.org>
Maciej Sent: Monday, March 01, 2010 12:22 PM > On Mar 1, 2010, at 11:57 AM, Joe D Williams wrote: > >>> no schema language can capture all the conformance requirements of >>> XHTML5. >> >> maybe so, because some requirements are runtime. > > Henri's not talking about runtime requirements. The static machine- > checkable syntax conformance requirements of HTML5 cannot be fully > and correctly expressed in any of the existing popular schema > languages. OK, like the URI example? > >> If we can't produce a valid (highly informative) XML Schema that >> can accurately represent the authortime syntax and sctructure >> requirements, then there will be no firm standards-track crosscheck >> between authortime content structures, the intent of the standard, >> and the runtime of the operating browser. > > The crosscheck would be to use the validator. Aren't we seeing some success with schema-driven validators? With content exceptions present in html5 I could expect that some hand-tooling would be required to accept all html5 code, but I also would believe it should be possible to construct a schema that could valdate a target "correct' or recommendied form that could tell us if elements are not structured as intended by the spec, and some other details. > If you want a schema that approximates most of the requirements, > validator.nu includes a RelaxNG schema that anyone could use for > their own purposes. But it should not be assumed that any content > satisfying this schema is correct. I think I understand the the limits of content correctness in validation, but the schema just tells about elements and attributes and acceptable structures and maybe values, froms, ranges. Maybe my experience, or what I think I am getting is wrong. I believe that the browser could run something just fine that would not pass validation, but if valid, it should at least run. > > My understanding is that DTDs and XML Schema are both significantly > weaker than Relax NG and can represent even fewer of the > requirements accurately. DTD for sure no way, I think. I am looking for a schema example. What element/attribute structures, attribute values, and content element features in html5 can't be shown via xml schema. The ones I might be able to name I hope are fixup cases where maybe something in the user code has been left out and gets 'fixed' in some way by the browser. Schema validation should fail that until fixed. Or, things that are obsoleted but ok, and maybe others like that where the html5 UA makes up for missing information. But I do not see main structural stuff in html5 that seems out of line. So, I would still be looking for an example of what parts/structures/content of html5 can't be modelled with the mostly standard XML schema? Sam > Second, I suggest that people who wish to discuss this topic (yet again!) do so in the context of bug 8611: http://www.w3.org/Bugs/Public/show_bug.cgi?id=8611 Yes, for html it should cover only the recommended html constructions (no fixups and few if any execeptions allowed) and all valid xhtml constructions should be documented. Thanks and Best Regards, Joe
Received on Monday, 1 March 2010 23:11:36 UTC