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Re: ISSUE-76: Need feedback on splitting Microdata into separate specification

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 8 Dec 2009 19:08:53 -0600
Message-ID: <dd0fbad0912081708s337fa47cm7820545fd9e7d761@mail.gmail.com>
To: John Foliot <jfoliot@stanford.edu>
Cc: Ian Hickson <ian@hixie.ch>, Martin McEvoy <martin@weborganics.co.uk>, Toby Inkster <tai@g5n.co.uk>, public-html <public-html@w3.org>
On Tue, Dec 8, 2009 at 5:31 PM, John Foliot <jfoliot@stanford.edu> wrote:
> Ian Hickson wrote:
>> On Tue, 8 Dec 2009, Martin McEvoy wrote:
>> > It would allow microdata to become language-neutral, and more modular,
>> > allowing people to use and develop microdata for their own specs and
>> > not worry too much about the effects, constraints or changes in HTML.
>> Making microdata language-neutral would make it far less compelling than
>> it is. The integration with HTML is one of its main qualities.
> So is this sort of like saying that if microdata was language neutral
> (i.e. Universal Design) it would be less useful then if used in it's
> current fashion (i.e. Feature for only one user-group - HTMLers)?
> Interesting...

To be precise, it's saying that if the Microdata format was universal,
it wouldn't be as useful to HTML as it is now, with an HTML-specific

This shouldn't come as a surprise.  Any time you can customize
something to match another, it's going to be more useful.
Specifically, HTML can specify some shortcuts that wouldn't be
reliable if Microdata were general-purpose (like taking @datetime from

That doesn't mean you can't adapt it to another language.  You'd just
have to reverse some of the html-specific shortcuts, and hopefully
make some of your own to maximize the usefulness of it for that
language.  If we look back at the list that Toby Inkster created:

       - if the element has an itemscope attribute, use the item;
       - otherwise, if it has a content attribute, use that;
       - otherwise, if it has an href attribute, use that;
       - otherwise, if it has a src attribute, use that;
       - otherwise, if it has a datetime attribute, use that;
       - otherwise, use the text content.

We see that in general we can probably rely on the first and last, and
possibly the second rule (if the language doesn't use @content for
anything else).  The rest are optimizations designed to make it more
suitable for HTML.  Microdata would indeed be much less attractive if
it didn't have the ability to rely on these shortcuts; it would make
it much more cumbersome to specify links and times as data, both of
which we can expect to be reasonably common things to do.  (You'd
probably have to fall back to using <meta content> more, duplicating
the data in your page.)

Received on Wednesday, 9 December 2009 01:09:33 UTC

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