[whatwg] Annotating structured data that HTML has no semantics for

Dan Brickley danbri at danbri.org
Thu May 14 05:25:42 PDT 2009

On 14/5/09 14:18, Shelley Powers wrote:
> James Graham wrote:
>> jgraham at opera.com wrote:
>>> Quoting Philip Taylor <excors+whatwg at gmail.com>:
>>>> On Sun, May 10, 2009 at 11:32 AM, Ian Hickson <ian at hixie.ch> wrote:
>>>>> One of the more elaborate use cases I collected from the e-mails
>>>>> sent in
>>>>> over the past few months was the following:
>>>>> USE CASE: Annotate structured data that HTML has no semantics for, and
>>>>> which nobody has annotated before, and may never again, for private
>>>>> use or
>>>>> use in a small self-contained community.
>>>>> [...]
>>>>> To address this use case and its scenarios, I've added to HTML5 a
>>>>> simple
>>>>> syntax (three new attributes) based on RDFa.
>>>> There's a quickly-hacked-together demo at
>>>> http://philip.html5.org/demos/microdata/demo.html (works in at least
>>>> Firefox and Opera), which attempts to show you the JSON serialisation
>>>> of the embedded data, which might help in examining the proposal.
>>> I have a *totally unfinished* demo that does something rather similar
>>> at [1]. It is highly likely to break and/or give incorrect results**.
>>> If you use it for anything important you are insane :)
>> I have now added extremely preliminary RDF support with output as N3
>> and RDF/XML courtesy of rdflib. It is certain to be buggy.
> So much concern about generating RDF, makes one wonder why we didn't
> just implement RDFa...

Having HTML5-microdata -to- RDF parsers is pretty critical to having 
test cases that help us all understand where RDFa-Classic and HTML5 
diverge. I'm very happy to see this work being done and that there are 
multiple implementations.

As far as I can see, the main point of divergence is around URI 
abbreviation mechanisms. But also HTML5 might not have a notion 
equivalent to RDF/RDFa's bNodes construct. The sooner we have these 
parsers the sooner we'll know for sure.


More information about the whatwg mailing list