- From: Chris Lilley <chris@w3.org>
- Date: Thu, 15 Feb 2007 22:39:19 +0100
- To: Dan Connolly <connolly@w3.org>
- Cc: public-xml-versioning@w3.org
On Thursday, February 15, 2007, 10:22:00 PM, Dan wrote: DC> On Thu, 2007-02-15 at 18:02 +0100, Chris Lilley wrote: >> Hello public-xml-versioning, >> >> Dan wrote: >> > I'm interested in a form of extensibility where a markup >> > language designer can make a new my:box element and >> > say "it's an HTML block element"; then, when a >> > document containing a my:block element is checked >> > for syntactic happiness, the checking tool uses >> > normal HTML schemas until it gets to my:box; then >> > it looks up my:box in the web, finds that it's >> > declared to be an HTML block, and find than >> > an HTML block is allowed here, and carries on happily. >> >> Thats interesting, but it seems to assume a top-down model where >> extensions are tightly bound to their expected environment. What if I >> want to use my:box inside Timed Text, or inside SVG? DC> Yes, I'm influenced by the "XML functions" idea that Tim DC> has advocated in the context of a related issue that I DC> neglected to mention... DC> http://www.w3.org/2001/tag/issues.html?type=1#xmlFunctions-34 DC> -> http://www.w3.org/DesignIssues/XML DC> It's largely top-down, i.e. compositional. Yes. Which is why I was puzzled recently to hear 'top down' used as a negative term, and used in opposition to 'Web-like'. DC> See DC> also "4. Elaboration defined: top-down treewalk, signals and namespaces" DC> in a recent draft by Henry Thompson. DC> http://www.w3.org/2001/tag/doc/elabInfoset.html DC> I expect that the 'HTML block' concept (substitution group?) could DC> be shared with Timed Text and SVG, though I haven't worked out any DC> of the details. I suspect you will find that it works sort of for TT, not at all for SMIL, and only slightly for SVG. Its another example of "it seems to work for HTML" != "works for any generic XML". I say "seems to" because it doesn't always work for HTML either. Lets suppose HTML had no style element and no script element and I propose to add them. Suppose I tell you that cl:style and cl:script are html:block. Where does that get you? DC> [...] >> I can point to some worked examples using RNG (and the same in DTD) >> >> Here >> http://www.rddl.org/xhtml-rddl.rng >> is the schema for RDDL. It could hardly be simpler. DC> If you have time to elaborate some other piece of the puzzle, DC> I'd appreciate it. I strongly suggest reading Robin Berjon's thoughts on composing namespaces and designing schemas: http://lists.w3.org/Archives/Public/www-archive/2005Sep/att-0014/schema-compounding-and-BP.html DC> I'd like to see how that schema is used with other schemas in DC> a document. DC> something analagous to one of these two... DC> http://www.w3.org/XML/2000/04schema-hacking/xhtml-mathml-ex.html DC> http://www.w3.org/XML/2000/04schema-hacking/comment-test.html >> > I'm also interested in whether CDF/WICD can/should use substitution >> > groups. >> > http://www.w3.org/TR/WICD/ >> >> They decided to use NVDL and RelaxNG instead. DC> Anybody have pointers to more details about that? I don't DC> see "NVDL" in that particular tech report. The first draft of CDI - Compound Documents by Inclusion - has not been published. The question of composing multi-namespace, multi-schema documents does not arise if they are only using linking rather than inclusion. Or were you asking for more details on NVDL in general? -- Chris Lilley mailto:chris@w3.org Interaction Domain Leader Co-Chair, W3C SVG Working Group W3C Graphics Activity Lead Co-Chair, W3C Hypertext CG
Received on Thursday, 15 February 2007 21:38:52 UTC