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Re: HTML+RDFa Issues (update)

From: Ben Adida <ben@adida.net>
Date: Wed, 01 Jul 2009 23:19:42 -0700
Message-ID: <4A4C517E.40804@adida.net>
To: Manu Sporny <msporny@digitalbazaar.com>
CC: RDFa mailing list <public-rdf-in-xhtml-tf@w3.org>

Hi folks,

I thought I'd be able to make it to the call this week, but last minute
stuff before a short 4th of july trip are making it impossible, so
regrets from me.

I'll write some thoughts on Manu's points below after the (US) holiday
weekend :)

-Ben

Manu Sporny wrote:
> We had a fairly productive discussion last week (draft minutes[1])
> regarding the most pressing issues surrounding HTML+RDFa. A brief
> summary of the findings can be found here:
> 
> http://rdfa.info/wiki/rdfa-in-html-issues#RDFa_Task_Force_Discussion_Order
> 
> Regrets for the call tomorrow, I won't have Internet access.
> 
> Some quick thoughts on the next set of issues:
> 
> == Processing of xmlns:* in non-XML languages ==
> 
> I think that we should phase out xmlns:* for the following reasons:
> 
>  * There is a case-sensitivity issue when used in HTML4 markup.
>  * It's technically feasible, but has led to a number of
>    namespace rants and "polluting HTML4/5 with namespaces" rants.
> 
> We could replace xmlns:* with @prefix or Mark's upcoming @token
> proposal. xmlns:* should exist for backwards compatibility, but we could
> suggest that it may be phased out in future versions of RDFa and should
> not be used for new markup.
> 
> == Case sensitivity for xmlns: attributes and prefixes in attribute
>    values ==
> 
> As Shane has mentioned previously, we should immediately update the
> XHTML+RDFa errata document to say that all prefixes specified by xmlns:
> should be lower-case. In other words, authors SHOULD NOT use mixed case
> for prefixes. Therefore, doing the following would be frowned upon:
> 
> xmlns:Foo or xmlns:FooBar or xmlns:FOOBAR
> 
> the suggested markup should be:
> 
> xmlns:foo or xmlns:foobar or xmlns:foobar
> 
> I agree with Shane's assessment: I don't think we need to change the
> parsing rules to lower-case prefix names in xmlns:. We should provide
> guidance to authors so that if they want to create markup that works in
> both HTML and XHTML, they should not mix case if xmlns: is used.
> 
> This point isn't moot if we transition away from using xmlns:* - we will
> still need to provide guidance for those that continue to use xmlns:* in
> XHTML1.1 documents.
> 
> = Use of regular CURIEs in @rel =
> 
> I believe that Julian Reschke has raised this issue several times. I
> don't remember the technical issue and I remember Ben stating clearly
> that there isn't a technical issue.
> 
> I don't have any input on this at the present time. Clearly, if a
> technical issue exists with CURIEs in @rel - we must address it.
> 
> = Script-based modification of DOM =
> 
> If we include language to address this issue in an XYZ+RDFa document,
> the language should be minimal.
> 
> The only time that RDFa enters the picture is when the
> (X)HTML/Javascript model/control layer serializes/streams the (X)HTML
> document into/to a tree model and hands it off to the RDFa parser. The
> RDFa parser shouldn't have any knowledge of how the tree model is
> generated - but we shouldn't be strict about making this point.
> 
> Re-parsing can be done whenever a DOM changed happens, on a X second
> timeout basis, or at the leisure of the browser - for example, when CPU
> usage is low.
> 
> If this is a question of /when/ the RDFa parser should be called, our
> answer should be "whenever the application layer wants to run the RDFa
> parser".
> 
> If this is a question of /how/ the RDFa parser should be called, we
> shouldn't go to great lengths to specify how that is done. For example,
> if speed optimizations for incremental DOM parsing of an HTML document
> (versus complete parsing of the HTML document) are desired - the
> implementation is up to the implementer of the incremental RDFa parser
> (which would need specific hooks into the DOM layer and vice versa).
> 
> The important part is that the triples that are generated via an
> incremental RDFa parser should be exactly the same as if the document
> was parsed fully. I don't think we need to specify much more than that.
> 
> -- manu
> 
> [1] http://www.w3.org/2009/06/25-rdfa-minutes.html
> 
Received on Thursday, 2 July 2009 06:20:18 GMT

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