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Re: <time> values in HTML5

From: Tantek Çelik <tantek@cs.stanford.edu>
Date: Mon, 21 Nov 2011 16:46:54 +0000
Message-ID: <2139870319-1321894018-cardhu_decombobulator_blackberry.rim.net-1656943875-@b11.c18.bise6.blackberry>
To: "Jeni Tennison" <jeni@jenitennison.com>,www-xml-schema-comments@w3.org,"HTML Data Task Force WG" <public-html-data-tf@w3.org>
Cc: "RDFa WG" <public-rdfa-wg@w3.org>,public-html-xml@w3.org
I've been working directly on the enhanced <time> element, here is my advice accordingly.

Since these new <time> values are both very recently specified in WHATWG HTML, and are still being discussed as part of the HTMLWG change control process for HTML5 and thus have some likelihood of change (should only be considered somewhat stable), I'd suggest that for the purposes of transcoding to existing type/value systems (eg XML Schema 1.1) that the new values:

1. Be treated as a simple string
2. Provide input to the next iteration of such existing type systems (eg XML Schema 1.2). Thus I would not hold back or modify any (even imminent) CR drafts.

BTW as a point of W3C process, I don't think it's permissible to add new features to a CR without first going back to a last call that includes those new features.



-----Original Message-----
From: Jeni Tennison <jeni@jenitennison.com>
Date: Sat, 19 Nov 2011 00:05:56 
To: <www-xml-schema-comments@w3.org>; HTML Data Task Force WG<public-html-data-tf@w3.org>
Cc: RDFa WG<public-rdfa-wg@w3.org>; <public-html-xml@w3.org>
Subject: <time> values in HTML5


The all new <time> element has been specced out in the WHATWG version of the HTML(5) spec at:


(This isn't reflected in the W3C Editors Draft as yet but I guess it will be at some point.)

As specced, it (a) accepts a bunch of syntaxes that aren't in the lexical space of any XML Schema datatype and (b) accepts some values that aren't in the value space of any XML Schema datatype, namely timezones and weeks.

Looking at this from the perspective of extracting data into either RDF or XML systems, syntax variations aren't a particular issue, as values can be normalised to the standard lexical space for the relevant XSD type as they're extracted. However, there's simply no appropriate datatype to use when mapping the values that aren't covered by XML Schema.

I see XML Schema 1.1 [1] is at Candidate Recommendation stage. Is it too late to slip in a xs:timezone and a xs:gYearWeek? Or should HTML+RDFa 1.1 do like the XPath Data Model did [2] and add definitions for these types so it can use them? Or should the types be created in a completely different namespace? Or should values of these types go typeless into any RDF or XML generated from HTML5?

Any thoughts?


[1] http://www.w3.org/TR/xmlschema11-2/

[2] http://www.w3.org/TR/xpath-datamodel/#types-predefined

Jeni Tennison

Received on Monday, 21 November 2011 16:47:35 UTC

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