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Re: HTML 5

From: Mark Birbeck <mark.birbeck@webbackplane.com>
Date: Wed, 16 Jul 2008 15:50:19 +0100
Message-ID: <ed77aa9f0807160750t205c3a40tee7a1eb8e1cc9af8@mail.gmail.com>
To: "Michael Bolger" <michael@michaelbolger.net>
Cc: public-rdf-in-xhtml-tf.w3.org <public-rdf-in-xhtml-tf@w3.org>

Hi Michael,


My first comment would be that RDFa will work fine with HTML 5. It was
designed to be 'embeddable' in any mark-up language. It just so
happened that the original work was XHTML oriented, but as Jeremy has
pointed out, RDFa works fine in HTML too, since the algorithm is
defined simply in terms of traversing a DOM.

(Shane is also right about validation, etc., but that's more about W3C
processes, and so on.)

My second comment is that from what I understand of the @data-property
feature in HTML 5, I don't think it's meant to be anything like RDFa.
I think the idea is simply that it provides a standard extension point
for adding *any* metadata to an element.

For example, say I have a page that has some script attached that
places a Google map into a div, on load. The document might look like

  <div id="map"></div>

Now, what if I want to centre that map on a certain location? It's
easy to do in script...I just call the centre function with the
appropriate long/lat.

But what if I want to give the document author a bit of control over
that? The easy way to do it is to modify my script so that it picks up
the centre from somewhere. It doesn't really matter where, because
this value is a 'contract' between the programmer and the page author.

One way that this is often done is to play around with classes:

  <div id="map" class="longlat 23;23"></div>

This is flakey, but at least the document validates. My understanding
of the HTML 5 proposal is that they are simply suggesting that this is
replaced with:

  <div id="map" data-property="longlat" data-content="23;23"></div>

But note that I don't believe that the idea is to create a *globally*
valid name in @data-property; I don't think anyone would say that
authors should all agree on the use of 'longlat' as the property
value, for example. And for this reason, this feature plays a very
different role to RDFa.

I think this is actually a useful feature, and my feeling is that when
we get some time we should look at how to complement this in RDFa. For
example, if there is a DOM API way of getting these values, we could
specify that RDFa adds its values to that list.

So with respect to John, he is mixing apples and oranges by proposing
that RDFa uses the @data-property instead of @property. (Not to
mention that RDFa is further in the W3C process than HTML 5.)

You could argue the other way round, that HTML 5 doesn't need
@data-property, since it could use @property, but to do that we'd need
to say that unprefixed values are 'local' to the current
document...but I lost that argument a long time ago. ;)

So peaceful co-existence seems the best option. :)

I hope that helps!



On Wed, Jul 16, 2008 at 3:19 PM, Michael Bolger
<michael@michaelbolger.net> wrote:
> Mark Birbeck wrote:
>>clarify what question you are asking?
> Greetings Mark,  a long time ago, looking forward to XHTML 2,
> was a great idea to me. Apparently the browser builders had
> other plans(bummer).
> So RDFa looks great now, since HTML 5 seems to be
> "rolling_out" over the next couple of years, what can be used
> today, tomorrow?
> Nothing against XHTML 2..
> What are your thoughts, improvements to John's approach ?
> Think it would be good for RDFa in HTML 5, what do you
> recommend:)
> Thank You
> Michael Bolger
> Mark Birbeck wrote:
>> Hi Michael,
>> Could you clarify what question you are asking?
>> Thanks.
>> Mark
>> On Wed, Jul 16, 2008 at 2:52 PM, Michael Bolger
>> <michael@michaelbolger.net> wrote:
>>> What about this(please) concerning HTML 5?
>>> http://ejohn.org/blog/bbc-removing-microformat-support/
>>> becomes this HTML 5:
>>> <span data-xmlns="cc:http://creativecommons.org/ns#
>>> dc:http://purl.org/dc/elements/1.1/">
>>> <span rel="dc:type" href="http://purl.org/dc/dcmitype/Text"
>>> data-property="dc:title">My Book</span> by
>>> <a rel="cc:attributionURL" data-property="cc:attributionName"
>>> href="http://rejon.org/my_book">Jon Phillips</a>
>>> is licensed under a
>>> <a rel="license"
>>> href="http://creativecommons.org/licenses/by-nc/3.0/">Creative Commons
>>> Attribution Non-Commercial 3.0 License</a>.
>>> <span rel="dc:source" href="http://deerfang.org/her_book"/>
>>> Permissions beyond the scope of this license may be available at
>>> <a rel="cc:morePermissions"
>>> href="http://somecompany.com/revenue_sharing_agreement">somecompany.com</a>.
>>> </span>
>>> thanks
>>> michael bolger

Mark Birbeck, webBackplane



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Received on Wednesday, 16 July 2008 14:55:35 UTC

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