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Re: [css3-conditional] Review of the new grammar for @supports

From: L. David Baron <dbaron@dbaron.org>
Date: Thu, 7 Feb 2013 14:30:08 -0800
To: Florian Rivoal <florian@rivoal.net>
Cc: "www-style@w3.org" <www-style@w3.org>
Message-ID: <20130207223008.GA13454@crum.dbaron.org>
On Thursday 2013-02-07 22:25 +0100, Florian Rivoal wrote:
> I have taken this opportunity to review the entire draft, and it looks
> very good to me.
> 
> I only have two comments on the whole document:
> 
> * There is one issue left in the draft:
> "Issue 1: This needs to specify what to do if rule is the empty string,
> if it contains more than one CSS rule, or if it contains garbage after
> a valid rule."
> Unless there are backward compatibility concerns, I would say we should
> specify that under such conditions SYNTAX_ERR must be thrown. I am not
> strongly attached to this if someone has good reasons to prefer
> something else, but I think it is a simple and natural answer to the
> question.

As you saw, this discussion is now in this thread:
http://lists.w3.org/Archives/Public/www-style/2013Feb/0229.html
(we were writing email at the same time).

> * "The conditionText attribute, on getting, must return the result of
> serializing the associated condition."
> We had a discussion at the San Diego face to face about what the
> serialization of the supports_rule should look like, but I cannot find
> the conclusion we had reached in this draft. Has it been written into
> another document? Is it voluntarily left unspecified at the moment? I
> would not have a problem with this draft moving forward without
> serialization being specified, or with reopening the question, but
> since we had discussed it, I wonder where it went.

Ah, http://lists.w3.org/Archives/Public/www-style/2012Aug/0749.html
records that:
  #  - RESOLVED: .conditionText returns either the token stream or source text
  #              from the style rule, with no logical simplifications, just
  #              tokenization ones

I've implemented this resolution by adding the text:

  # conditionText of type DOMString (CSSSupportsRule-specific
  # definition for attribute on CSSConditionRule)
  #    The conditionText attribute (defined on the CSSConditionRule
  #    parent rule), on getting, must return the condition that was
  #    specified, without any logical simplifications, so that the
  #    returned condition will evaluate to the same result as the
  #    specified condition in any conformant implementation of this
  #    specification (including implementations that implement
  #    future extensions allowed by the general_enclosed
  #    exensibility mechanism in this specification). In other
  #    words, token stream simplifications are allowed (such as
  #    reducing whitespace to a single space or omitting it in cases
  #    where it is known to be optional), but logical
  #    simplifications are not allowed. 

in
http://dev.w3.org/csswg/css3-conditional/#the-csssupportsrule-interface
https://dvcs.w3.org/hg/csswg/rev/7dace721dff3

Does that seem ok to you?

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                           http://www.mozilla.org/   𝄂
Received on Thursday, 7 February 2013 22:30:33 GMT

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