[whatwg] RDFa is to structured data, like canvas is to bitmap and SVG is to vector
hsivonen at iki.fi
Sat Jan 17 12:25:59 PST 2009
On Jan 17, 2009, at 21:38, Shelley Powers wrote:
> I'm not doubting the effort that went into getting MathML and SVG
> accepted. I've followed the effort associated with SVG since the
> I'm not sure if the same procedure was also applied to the canvas
> object, as well as the SQL query capability. Will assume so.
Note that SVG, MathML and SQL have had different popularity
trajectories in top four browser engines than RDF.
SVG is going up. At the time it was included in HTML5 (only to be
commented out shortly thereafter), three of the top browser engines
implemented SVG for retained-mode vector graphics and their SVG
support was actively being improved. (One of the top four engines
implemented VML, though.)
At the time MathML was included in HTML5, it was supported by Gecko
with renewed investment into it as part of the Cairo migration. Also,
Opera added some MathML features at that time. Thus, two of the top
four engines had active MathML development going on. Further, one of
the major MathML implementations is an ActiveX control for IE.
When SQL was included in HTML5, Apple (in WebKit) and Google (in
Gears) had decided to use SQLite for this functionality. Even though
Firefox doesn't have a Web-exposed database, Firefox also already
ships with embedded SQLite. At that point it would have been futile
for HTML5 to go against the flow of implementations.
The story of RDF is very different. Of the top four engines, only
Gecko has RDF functionality. It was implemented at a time when RDF was
a young W3C REC and stuff that were W3C RECs were implemented less
critically than nowadays. Unlike SVG and MathML, the RDF code isn't
actively developed (see hg logs). Moreover, the general direction
seems to be away from using RDF data sources in Firefox internally.
Meanwhile, the feed example you gave--RSS 1.0--shows how the feed spec
community knowingly moved away from RDF with RSS 2.0 and Atom.
Furthermore, RSS 1.0 usually isn't parsed into an RDF graph but is
treated as XML instead. If RSS 1.0 is evidence, it's evidence
> The point I'm making is that you set a precedent, and a good one I
> think: giving precedence to "not invented here". In other words, to
> not re-invent new ways of doing something, but to look for
> established processes, models, et al already in place, implemented,
> vetted, etc, that solve specific problems. Now that you have
> accepted a use case, Martin's, and we've established that RDFa
> solves the problem associated with the use case, the issue then
> becomes is there another data model already as vetted, documented,
> implemented that would better solve the problem.
Clearly, RDFa wasn't properly vetted--as far as the desire to deploy
it in text/html goes--when the outcome was that it ended up using
markup that doesn't parse into the DOM the same way in HTML and XML.
hsivonen at iki.fi
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