Toby A Inkster wrote:
Calogero Alex Baldacchino wrote:
The concern is about every kind of metadata with respect to their
possible uses; but, while it's been stated that Microforamts (for
instance) don't require any purticular support by UAs (thus they're
backward compatible), RDFa would be a completely new feature, thus html5
specification should say what UAs are espected to do with such new
attributes.
RDFa doesn't require any special support beyond the special support that
is required for Microformats. i.e. nothing. User agents are free to
ignore the RDFa attributes. In that sense, RDFa already "works" in
pretty much every existing browser, even going back to dinosaurs like
Mosaic and UdiWWW.
Agents are of course free to offer more than that. Look at what they do
with Microformats: Firefox for instance offers an API to handle
Microformats embedded on a page; Internet Explorer offers its "Web
Slices" feature.
If it is true that RDFa can work today with no ill-effect in downlevel
user-agents, what's currently blocking its implementation? Concern for
validation?
It seems to me that many HTML extensions are implemented first and
specified later[1], so perhaps it would be in the interests of RDFa
proponents to get some implementations out there and get RDFa adopted,
at which point it will hopefully seem a much more useful proposition for
inclusion in HTML5.
In the short term the RDFa community can presumably provide a
specialized "HTML5 + RDFa" validator for adopters to use until RDFa is
incorporated into the core spec and tools.
It would seem that it's much easier to get into the spec when your
feature is proven to be useful by real-world adoption.
[1] canvas, keygen, frames and script are examples of this phenomenon.