[whatwg] RDFa is to structured data, like canvas is to bitmap and SVG is to vector

Shelley Powers shelleyp at burningbird.net
Sat Jan 17 11:30:18 PST 2009

Sam Ruby wrote:
> On Sat, Jan 17, 2009 at 1:33 PM, Dan Brickley <danbri at danbri.org> wrote:
>> On 17/1/09 19:27, Sam Ruby wrote:
>>> On Sat, Jan 17, 2009 at 11:55 AM, Shelley Powers
>>> <shelleyp at burningbird.net>  wrote:
>>>> The debate about RDFa highlights a disconnect in the decision making
>>>> related
>>>> to HTML5.
>>> Perhaps.  Or perhaps not.  I am far from an apologist for Hixie, (nor
>>> for that matter and I a strong advocate for RDF), but I offer the
>>> following question and observation.
>>>> The purpose behind RDFa is to provide a way to embed complex information
>>>> into a web document, in such a way that a machine can extract this
>>>> information and combine it with other data extracted from other web
>>>> pages.
>>>> It is not a way to document private data, or data that is meant to be
>>>> used
>>>> by some JavaScript-based application. The sole purpose of the data is for
>>>> external extraction and combination.
>>> So, I take it that it isn't essential that RDFa information be
>>> included in the DOM?  This is not rhetorical: I honestly don't know
>>> the answer to this question.
>> Good question. I for one expect RDFa to be accessible to Javascript.
>> http://code.google.com/p/rdfquery/wiki/Introduction ->
>> http://rdfquery.googlecode.com/svn/trunk/demos/markup/markup.html is a nice
>> example of code that does something useful in this way.
> The fact that this works anywhere at all today implies that little, if
> any, changes to browsers is required in order to support this.  Is
> that a fair statement?
> I've not taken a look at the code, but have taken a quick glance at
> the output using IE8.0.7000.0 beta, Safari 3.2.1/Windows, Chrome
>, Opera 9.63, and Firefox 3.0.5.
> The page is different (as in less functional) under IE8 and Safari.
> Is there something that they need to do which is not already covered
> in the HTML5 specification in order to support this?

I would think we would have to go through the code to see what this 
specific instance of client-side access of the RDFa isn't working. The 
debugger I'm using with IE8 shows the problem is occuring in the jQuery 
code, not necessarily anything specific to the RDFa plugin.

I know other JavaScript libraries that work with RDFa work, at least 
with Safari. For instance:


Since this library was vetted for IE7, would assume it would work for 
IE8, too.

Of course, the RDFa attributes aren't incorporated into HTML5, which 
means their use would result in an invalid document. And of course, if 
they were incorporated, the issue of namespace for them would have to be 
addressed as namespaces were for MathML and SVG.

> - Sam Ruby

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