[css-page] OM for margin rules (was: [css3-fonts][cssom] CSSFontFeatureValuesRule vs. CSSKeyframesRule)

Le 30/05/2013 15:07, John Daggett a écrit :
> The problem with this line of reasoning is that it doesn't
> differentiate between nuggets of syntax that only live within a single
> given @-rule and *not* contain other rules (e.g. @font-feature-values)
> and rules intended to contain other rules such as @supports or @media.

I don’t see this as a problem. Each at-rule defines in what contexts it 
is allowed or not. For example @import is only allowed after any 
@charset "rule", and before any other rules such as style rules.

> This applies to all @-rules with no defined OM.  Look at css-page,
> @page is defined with a slew of @-rule thingies, each of which would
> seem to require a new CSSRule subtype and a clear OM definition, yet
> there's no such definition.

We discussed this in the WG a few months ago. There is good consensus 
that OM for margin rules is needed, and rough consensus on how to do it. 
I just haven’t done the edits yet. (And none of my three co-editors beat 
me to it.)

The idea is that CSSPageRule would inherit from CSSGroupingRule in 
addition to providing a CSSStyleDeclaration style attribute. The margin 
rules inside @page would be represented by new sub-types of CSSRule. I’m 
not sure yet if we should define 16 different types (and corresponding 
constants) or just one with an at_keyword or similar attribute.

Simon Sapin

Received on Thursday, 30 May 2013 08:10:16 UTC