[whatwg] Ghosts from the past and the semantic Web

[Greg Houston]

On Fri, Aug 29, 2008 at 3:31 AM, Shannon <shannon at arc.net.au> wrote:
> I think you see the problem to be solved as "RDF-in-HTML". I would prefer
> the problem defined as "Metadata-in-HTML".

It seems to me that everything they want to do could be done with the
data attribute except that attribute is meant to be private, which
could mean an assortment of things. John Resig mentioned it is private
in the sense that it does not effect layout or presentation, but it
could also be private in the sense that I don't have to worry about
someone else using any of my data names, e.g., I can use data-title,
data-blue, data-atari, and not worry about conflicts with anyone else.

Data is private, metadata is not. It seems like a metadata attribute
could be pretty much exactly like the data attribute but with
namespacing.

Then there is only one reserved metadata name and that is
metadata-namespace. The vocabulary file could be written in XML or
some language that doesn't exist yet. It tells you what it is in it's
doctype. What they want to add as HTML attributes instead they would
have to further define in their vocabulary (if they don't already),
e.g., typeof, about, property and so forth. They can make a thousand
new metadata attributes if they want, they just have to define them in
their vocabulary file.

<div id="Sarah"
	metadata-namespace="foo:http://mysite.com/foo/"
	metadata-foo="instanceof:Person;about:Sarah">
	<p><span metadata-foo="property:name">Sarah Foo</span></p>
	<p><span metadata-foo="property:job:title">CEO</span></p>
	<p><span metadata-foo="property:job:salary">$120,000</span></p>
	<p><span metadata-foo="property:age">32</span></p>
	<h3>Likes:</h3>		
	<ul metadata-foo="property:likes;rel:whatever;typeof:whatever">
		<li>chocolate</li>
		<li>stars</li>
		<li>green</li>
	</ul>				
</div>

I doubt this satisfies any of the general concerns about namespacing
and metadata polluting the HTML, but I think it does create a way to
add unlimited public attributes to elements without them each needing
to be added to the HTML spec. It also makes it very clear what
attributes are metadata related, where with something like the
following the RDFa metadata attributes are more intrusive, less
contained, more difficult to visually sift out from the rest of the
markup. RDFa is certainly not pleasant to look at and even less so
when mashed together with a microformat. I would definitely enjoy my
work much less if I had to stare at this sort of mess everyday.

<div class="vcard" id="weborganics"
		xmlns:foaf="http://xmlns.com/foaf/0.1/"
		typeof="foaf:Person"
		about="#weborganics">
<p><span property="foaf:name" class="fn">Martin McEvoy</span></p>
<p rel="foaf:img">
<img alt="weborganics" src="http://weborganics.co.uk/images/me.jpg"
class="photo"/>
</p>
<p>Contact: <a rel="foaf:mbox" title="Email" class="email"
href="mailto:info at weborganics.co.uk">Email</a>
Web: <a rel="foaf:weblog me" class="url"
href="http://weborganics.co.uk/index.xhtml">WebOrganics</a></p>
<div class="geo" id="weblog" rel="foaf:based_near"
	xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#">
    	<span typeof="geo:Point" about="#weblog">
		<abbr property="geo:lat" content="53.7552" title="53.7552"
class="latitude">N 53.7552</abbr>,
		<abbr property="geo:long" content="-2.3675" title="-2.3675"
class="longitude">W -2.3675</abbr>
    	</span>
</div>

Greg