On 16 November 2010 13:45, Aaron Steele eightysteele@gmail.com wrote:
Hi Peter,
The data that is generated using microdata looks to be very similar to RDFa, except that the properties are not qualified as URIs, and they seem to be limited to the properties available in the same location as the type definition due to the lack of qualification.
Interesting. So are there things that RDFa can do that microdata cannot do? Can you give an example?
I think I missed something when I first read through the Microdata draft, or it was updated in the last few hours, as it has todays date on it. On closer reading, there can be arbitrary URL's for properties, so there is no hassle there actually. The examples I was reading through before I went to the spec only used simple property names from the vocabulary matching the type of the item.
There is also a good specification of how to generate RDF from Microdata which includes some common Dublin Core terms as well known predicates for different parts [1]. However, you could write an RDFa parser that added the extra triples without having to create a new spec called Microdata.
I still don't think I would use Microdata, as it seems to duplicate the RDFa spec that has already been standardised by the W3C (since 2008!), even though technically it is for XHTML and not technically HTML (yet). The examples in [2] and [3] seem so similar that it seems like a waste of energy to recommend two slightly different ways to do the same thing.
[1] http://dev.w3.org/html5/md/#rdf [2] http://www.w3.org/TR/xhtml-rdfa-primer/#id84801 [3] http://dev.w3.org/html5/md/#names:-the-itemprop-attribute