Re: Feature queries

On Wednesday 2009-12-09 10:50 -0800, Simon Fraser wrote:
> There's a broader issue that we need to be aware of when trying to
> spec something like this on a property-by-property basis. Just
> because a browser implements parsing of a property doesn't mean
> that it fully implements the full behavior of the property.  For

I think the proposal is that it's testing for whether a particular
property+value combination is parsed, not just a particular
property.

> example, a browser could support transform: with 2d values, but
> not with 3d (as Firefox does now). Also, Google Chrome parses
> 3d-transform-related properties like -webkit-perspective and store
> them in the style system, but does not actually implement
> rendering of 3D transforms. This causes Modernizr to report that
> Chrome implements 3D transforms, when it does not.

That's just a bug in Chrome, and one that interferes with the
existing CSS mechanism for handling unsupported values (falling back
to the previous declaration) just as much as it interferes with this
one.

Implementations shouldn't parse values that they don't support.

-David

-- 
L. David Baron                                 http://dbaron.org/
Mozilla Corporation                       http://www.mozilla.com/

Received on Wednesday, 9 December 2009 22:08:21 UTC