Re: [css3-text-layout] New editor's draft - margin-before/after/start/end etc.

Shinyu Murakami wrote:

> I am still thinking that DDAs is a good idea and Mozilla and
> WebKit's *-start/end implementations seem good enough. But I also
> noted a smart proposal that fantasai wrote. See:
> http://lists.w3.org/Archives/Public/www-style/2006Jun/0084.html
> 
> In this proposal, logical properties (*-before/after/smart/end) are
> not aliases of physical properties (*-top/bottom/left/right) and
> each property cascades and receives its specified value
> independently and the priority between logical and physical is
> defined by the direction-model property. In this model, it can avoid
> "unhealthy inter-dependency between properties".

Murakami-san, other than the fact that creating new properties
provides a way of specifying style rules that only apply to user
agents that support vertical text, what are the advantages of
supporting logical properties?  I'm still unclear what the advantages
are to this proposal beyond the fallback handling.

John Daggett