Re: [css-counter-styles] status of "additional" predefined counter styles

On 09/09/2014 08:48, Tab Atkins Jr. wrote:
> On Mon, Sep 8, 2014 at 8:36 AM, Jonathan Kew <jfkthame@gmail.com> wrote:
>> In the current CSS Counter Styles draft,[1] we read that
>>
>> # These additional counter styles are not intended to be supported by
>> # user-agents by default
>>
>> (in reference to the styles listed in the i18n WG's document.[2])
>>
>> However, test results[3] indicate that webkit and blink do actually
>> implement a number of these as built-in counter styles; in particular, many
>> of the Indian script/language names (with the exception of 'tamil'), and
>> several more such as 'arabic-indic', 'persian', etc.
>>
>> A smaller number of the "additional" styles are also supported by Firefox,
>> such as 'armenian', 'greek', and a number of CJK styles; and a handful also
>> by IE.
>>
>> Should such styles be moved to the standard collection of predefined styles
>> within the Counter Styles spec, with the expectation that all browsers
>> should support them? If so, we need to determine which ones to move. Or
>> should browsers refrain from implementing these "additional" styles as
>> built-ins, so that it's clear to authors that an explicit @counter-style
>> rule is needed in order to use them? ISTM the current situation is unhelpful
>> from an interop point of view.
>
> Browsers generally shouldn't be implementing random things.  However,
> they did support a larger set than the spec currently requires; the
> rule we used was just "what was specified in CSS2 and 2.1" to decide
> what to keep.
>
> I'm fine with adding more things to the spec if browsers already
> implement them, particularly if there are compat issues to deal with.
> Feel free to implement what you need, and I'll reflect it in the spec
> as necessary.

The i18n WG discussed this in a telecon, and was also concerned that it 
might be confusing to content authors if browsers support counter-styles 
that are meant to be optional. It would be important to send out a clear 
message that you can't expect these built-in styles to be interoperable 
on all platforms.

On the other hand, if we suck those into the Counter Styles spec, that 
may help, especially given that some are supported already by both 
Webkit and Blink engines, and now Gecko too (although the choice seems a 
little arbitrary). On the other other hand, IE still doesn't support the 
styles - I don't know whether they plan to support the user-defined 
styling - if so, one would hope that they will also support the 
additional built-in styles. There is also the point that older browser 
versions for some time won't support the styles it is suggested that we 
move into the spec, but then that will be an issue for user-defined 
styles too.


To get some more specific information about what Jonathan was 
suggesting, I ran the tests on the latest Firefox, Safari and Chrome 
nightlies, and here is a summary of the current situation.


Counter-styles supported by Firefox, Chrome, Opera & Safari
(Those with * are also supported by IE, otherwise not.)  These are 
presumably the ones we are talking about adding to the spec.

arabic-indic
persian
armenian*
lower-armenian
upper-armenian  
bengali
devanagari
georgian*
lower-greek*
gujarati
gurmukhi
hebrew  
cjk-earthly-branch
cjk-heavenly-stem
hiragana  
katakana
hiragana-iroha
katakana-iroha
kannada
khmer  
cambodian
lao
malayalam  
mongolian
myanmar
oriya
telugu
thai
tibetan  




Additional counter-styles supported by Firefox, but not others

cjk-decimal
korean-hangul-formal
tamil




Counter-styles supported by Chrome, Safari & Opera (with small 
inconsistencies from spec) and not supported by Firefox. If Firefox was 
to add these quickly, they may qualify for inclusion in the spec, 
however the small divergences in the current implementations compared to 
the spec may need some attention. For a list of divergences, see the 
notes at 
http://www.w3.org/International/tests/repository/predefined-counter-styles/results-predefined-counter-styles#ethiopic

afar  
oromo
sidama
tigre


Hope that helps,

ri

Received on Thursday, 25 September 2014 19:05:29 UTC