Re: [css-page] Editorial issues regarding @page descriptors

On Sun, Jul 12, 2015 at 3:13 AM, Sebastian Zartner
<sebastianzartner@gmail.com> wrote:
> On 7 July 2015 at 21:15, Lea Verou <lea@verou.me> wrote:
>>> On Jul 6, 2015, at 17:50, Tab Atkins Jr. <jackalmage@gmail.com> wrote:
>>>
>>> Inheritance is defined over elements in the element tree.  If @page or
>>> the @margin rules inherit from an element, or vice versa, then they're
>>> in the element tree as well.  Like I said, at that point the
>>> page/margin boxes effectively become pseudo-elements that just have a
>>> weird at-rule-based syntax for legacy reasons.
>>>
>>> Where they go in the tree is ???.
>>
>> I do see inheritance and treating (some of?) them as properties as valuable in this case, as ideally one would want to be able to nest regular CSS rules inside @page rules, to specify styling for the fragments of elements matching the selector that happen to fall on a page that matches the @page rule. Currently it’s a severe limitation that publishers cannot style element fragments based on whether they fall on a left or a right page (for example), and this would provide an elegant and straightforward solution. There are of course the usual parsing issues with nesting, but these could be solved by prepending every such rule with a &. But this is getting a bit off topic for an editorial discussion…
>
> Regarding this discussion, I believe it should be clarified in some
> specification what is meant by the word "descriptor". My naive
> interpretation of a descriptor was that all properties, which apply to
> @-rules are descriptors. If there's a semantic difference to
> properties in regard of CSSOM, inheritance, etc., this should be
> clarified.

Descriptors aren't properties; the two sets are disjoint.  The
overarching word you're looking for is probably "declaration", which
describes the syntactic construct of `foo: bar` that both use.
Properties are things that elements have.  Descriptors are
non-properties that at-rules have, which don't apply to elements.
This doesn't actually need further clarification; the names are
defined and used appropriately across specs, save (possibly) for Paged
Media.

> In any case, within the Paged Media spec the wording still needs to be
> unified. So either all @page entities are 'descriptors' or all are
> 'properties'.

Well, not *necessarily* true (it's *possible* for @page declarations
to be a mix of those), but I agree that they should be all one or the
other.

~TJ

Received on Monday, 13 July 2015 17:42:49 UTC