On 20.9.2012 14:17, Sam Ruby wrote:
> I can confirm what Benjamin stated: the existing validator already
> supports multiple specifications, including extension specifications.
>
> The validator that is deployed on the W3C site is based on validator.nu.
> It is an instance proof that it is indeed practical to build such a
> validator.
Hi Sam, given that I recently hacked private copy of validator.nu to
support extension specification I think that I can say that I have quite
good understanding what validator can and can't do. :-)
> The interface at the W3C site produces a message as which extensions are
> included by default. The interface at the validator.nu site has an
> input field where you can list schemas to be included.
What I'm trying to say is that if number of extension specifications
will raise then it will be not so easy for validator. Given you have N
extension specifications there are 2^N of their combinations (hope I got
it right, it was long time ago since I attended last combinatory class
:-). And given the way how HTML5 schema is expressed in RELAX NG and
given some RELAX NG limitations on how it handles name classes (they are
not full fledget patterns) it is not just about having check box for
each additional schema.
Of course these are technical obstacles which can be solved with some
additional effort. But there is another side of problem -- users. Do you
think that ordinary Joe web designer will understand why he/she should
validate page as HTML5+BAR+FOO+BAZ instead just as HTML5?
I think that W3C and HTML WG should provide much clearer message about
role of extension specifications and their impact on document conformance.
Jirka
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