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Re: HTML+RDFa Issues (update)

From: Mark Birbeck <mark.birbeck@webbackplane.com>
Date: Thu, 2 Jul 2009 15:48:30 +0100
Message-ID: <ed77aa9f0907020748w40ee70bande659948564560f5@mail.gmail.com>
To: RDFa mailing list <public-rdf-in-xhtml-tf@w3.org>
To those that are left, is there any point in having a call? I'm not
sure there is much we can do.



On Thu, Jul 2, 2009 at 7:19 AM, Ben Adida<ben@adida.net> wrote:
> 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

Mark Birbeck, webBackplane



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Received on Thursday, 2 July 2009 14:49:17 UTC

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