[Bug 19684] [Shadow]: shadow reference combinator should be css function.

https://www.w3.org/Bugs/Public/show_bug.cgi?id=19684

Dimitri Glazkov <dglazkov@chromium.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jackalmage@gmail.com

--- Comment #1 from Dimitri Glazkov <dglazkov@chromium.org> ---
(In reply to comment #0)
> I think, /select/ is a little confusing for web developers. It would be
> better to use css function instead, e.g.
> - distributed-into(), or
> - selected-by()
> 
> I will write the reason why I suggest css function.
> Current shadow dom spec says, 
> 
> - The combinator value must be select
> - The first compound selector of the combinator must match an insertion point
> - The second compound selector must match an element, distributed to this
> insertion point
> 
> Its example is .some-insertion-point /select/ div.special.
> 
> However, any element can have "select". For example, users can write '<div 
> class="some-insertion-point" select="...">'.
> 
> So it is difficult to know whether /select/ is just reference combinator or
> shadow reference combinator.

"select" is not a valid attribute for a "div".  I don't see what is difficult.

> 
> For example,
> <div class="shadow-host">
>    <#shadow-root>
>       <style>
>       .some-insertion-point /select/ div.special { color: red; }
>       </style>
>       <div class=".some-insertion-point" select="#B">
>       <content class=".some-insertion-point">
>       <div id="B">This text is red?</div>
>    </#shadow-root>
>    <div class="special">This text should be red!</div>
> </div>
> 
> The ".some-insertion-point /select/ div.special { color: red; }" should be
> applied to distributed node or just div in shadow dom subtree? Both?
> 
> The most difficult thing is that we cannot decide whether
> ".some-insertion-point" points really insertion points or not when parsing
> the rule.
> 
> So by using css function, we can write:
> - div.special:distributed-into('.some-insertion-point') { color: red; }, or
> - div.special:selected-by('.some-insertion-point') { color: red; }
> 
> This is very easy to know that the style should be applied to distributed
> nodes.
> 
> What do you think about this?

I think the example you brought up is rather weak. I honestly don't see a
problem with this. Thus, in my opinion, this is bike-shedding.

Also, you need to argue with Tab and the CSS WG about this. He is the one who
recommended to use reference combinator.

Also, here's more information on the reference combinator:
http://www.w3.org/TR/selectors4/#idref-combinators

-- 
You are receiving this mail because:
You are the QA Contact for the bug.