Philip Taylor wrote:
On Tue, May 12, 2009 at 11:55 AM, Eduard Pascual <herenva...@gmail.com> wrote:
[...]
(at least for now: many RDFa-aware agents vs. zero HTML5's
microdata -aware agents)
HTML5 microdata parsers seem pretty trivial to write -
http://philip.html5.org/demos/microdata/demo.html is only about two
hundred lines to read all the data and to produce JSON and
N3-serialised RDF. It shouldn't take more than a few hours to produce
a similar library for other languages, including the time taken to
read the spec, so the implementation cost for generic parser libraries
doesn't seem like a significant problem.
Writing something that will produce triples may be easy, but what's
important is that you're producing an RDF model.
Philip, I've been looking at your application, and you're not producing
the same model for Ian's microdata proposal that is produced using
either eRDF or RDFa. I'll have more on this later.
The cost of integration with backend RDF-based systems seems more
significant - hopefully you could simply replace the frontend RDFa
parser with a microdata parser and generate the same RDF triples and
it would all work fine, but I don't know whether that's true in
practice (because maybe the microdata syntax is too restrictive to
represent the vocabularies people want to use, and so they'd have to
go to lots of extra effort to create a new vocabulary).
[...] there are other cases where
separate values might be needed: for example using a street address
for the human-readable representation of a location and the exact
geographic coordinates as the machine-readable (since not all
micro-data parsers can rely on Google Maps's database to resolve
street addresses, you know); or using a colored name (such as "lime
green" displayed on lime green color) as the human-readable
representation of a color, and the hexcode (like #00FF00) as the
machine-readable representation.
You could replace
<span itemprop="color">lime green</span>
<span itemprop="location">1 High Street</span>
with
<meta itemprop="color" content="#00FF00"><span>lime green</span>
<meta itemprop="location.lat" content="56.78"><meta
itemprop="location.long" content="-12.34"><span>1 High Street</span>
to get the desired output. (Not particularly elegant syntax, though.)
It's funny, but oddly enough, this discussion reminds me of when I
started at Boeing, right after college. I started just when the great
debate between SQL and QUEL was ending, in SQL's favor. Most folks still
feel that QUEL was the "superior" option, but SQL won out in the end
because it had widespread use, and was supported by more of the
(powerful) database companies, and hence the companies using the databases.
The same could be said of Betamax versus VHS, and even the recent HDTV
and Blu-Ray debates: we can get caught up in issues of superiority and
argue the fine points of (mostly) obscure markup until the cows come
home, but at some point in time, you have to pick a standard to get
behind, or no one will any confidence in _any_ of the options being
proposed--and the concept underlying the competing technologies (or
standards) is hindered, perhaps for years.
Sorry, I digress. Eduard, looking forward to seeing your own
interpretation of the best metadata annotation.
Shelley
