Re: [css-writing-modes-3] 7.7 Table Caption Mappings: caption-side

On Mon, Aug 10, 2015 at 8:44 PM, Gérard Talbot <www-style@gtalbot.org> wrote:
> Hello,
>
> "
> Implementations that support the top and bottom values of the caption-side
> property but do not support side captions (i.e. left and right captions in
> horizontal writing modes) must treat both top and bottom as block-start,
> when the table is in a vertical writing mode.
> "
> 7.7 Table Caption Mappings: the caption-side keywords
> http://www.w3.org/TR/css-writing-modes-3/#caption-side
> https://drafts.csswg.org/css-writing-modes-3/#caption-side
>
> I see 2 problems with such sentence.
>
> 1-
> If an implementation supports top and bottom values of the caption-side
> property but do not support side captions (i.e. left and right captions in
> horizontal writing modes), why it should not treat top as block-start on one
> hand and bottom as block-end on the other hand? Why treat both top and
> bottom as block-start?

This is error-recovery intended to make the captions at least
renderable.  We don't want people to depend on top/bottom being
interpreted logically just because some impls don't support side
captions, so we don't make it too smart.  This is a relatively common
practice when handling error-recovery - do the minimum possible to
make the page readable.

> 2-
> The way the sentence is written could also be subject of interpretation. If
> an implementation supports top and bottom values of the caption-side
> property, then it must do "x" regardless of its support of side captions.
> The sentence could suggest that there will be a different normative
> procedure when an implementation supports side captions... when there should
> not be any difference.

I don't understand how you could interpret it that way.  There are two
conditions in that sentence, so you have to satisfy both of them for
the following requirement to apply.  There is no way to misinterpret
it without simply misreading the sentence.

~TJ

Received on Tuesday, 11 August 2015 18:11:31 UTC