Re: CSSStyleDeclaration: Setting only a value or a priority

On Thursday 2013-08-22 08:13 +0200, Simon Pieters wrote:
> On Wed, 21 Aug 2013 23:46:04 +0200, L. David Baron
> <dbaron@dbaron.org> wrote:
> 
> >I think this is a really bad idea (which has apparently now made its
> >way into the spec according to comments in
> >https://bugzilla.mozilla.org/show_bug.cgi?id=903239 , although I
> >don't see any mention in this thread of it).
> 
> http://lists.w3.org/Archives/Public/www-style/2013Aug/0297.html

Sorry, missed the one-liner in the midst of the quote.

> >The underlying mental model of setProperty has, I think, always been
> >"append declaration".  The object model of declaration blocks was
> >designed without an idea of preserving order; setProperty appends a
> >declaration to the end.  Thus setProperty with no priority being a
> >no-op if the declaration block already has an !important declaration
> >for that property.
> 
> setProperty with no priority was *not* a no-op in the previous spec.
> Instead, it would set the value and unset important. This is what
> Gecko (and Presto) implements also.
> 
> http://software.hixie.ch/utilities/js/live-dom-viewer/saved/2472

OK, I guess it was originally implemented that way but changed in
https://bugzilla.mozilla.org/show_bug.cgi?id=556661 .  I guess I
should have thought about that more carefully.  I'd probably prefer
to revert that change.

> It's no-op in WebKit/Blink/IE, though.
> 
> As I said before I made the change, I can see an argument for why
> no-op behavior can be desirable, and asked if we should change the
> spec to do that. Nobody replied to that.
> 
> http://lists.w3.org/Archives/Public/www-style/2013Aug/0247.html

Sorry; I basically can't keep up with everything on www-style.
Nonetheless, I object to the attempt to implement this
undefined/empty string difference in Gecko, which I think is a bad
idea, and don't plan to accept.

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
             Before I built a wall I'd ask to know
             What I was walling in or walling out,
             And to whom I was like to give offense.
               - Robert Frost, Mending Wall (1914)