[CSS21] WD 9.2: box relations & properties undefined

CSS cannot be implemented for visual media without knowing what the
(ordered) siblings, parents and children of a box are, and what the
properties of a box are.

The current specification doesn't in general give this information.

I realize that it's difficult to provide this specification, I'm merely
noting it as a barrier to implementability.  So "status of this document"
would have to be worded rather weakly as to how implementable the
specification is if the existing specification text is to be retained
unchanged.

If we are to address it within CSS2.1, then my current thoughts are that
§9.2 ("Controlling box generation") give a specification of a box tree
as a function of the pseudo-element tree (by which I mean the tree formed
from the source document element tree by applying :before and :after),
and that it tie together sections 9.2.3 (run-in), 12.5.1
(list-style-position:inside), 17.2.1 (anonymous table object creation)
9.2.1.1 (anonymous block box creation) and 9.2.2.1 (anonymous inline
boxes), so that it's clear how those sections interact.  This "tying
together" is somewhat similar to writing an implementation of CSS in a
functional or logic programming language.

pjrm.

Received on Sunday, 9 January 2011 17:46:32 UTC