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Re: [css-flexbox] [css-align] unprefixing alignment properties before css-align

From: Christian Biesinger <cbiesinger@google.com>
Date: Tue, 18 Jun 2013 14:38:02 -0700
Message-ID: <CAPTJ0XFCmfJt=wjNJUZBcXJsJiwAZ26UiKG7vSjc_-v0wepjag@mail.gmail.com>
To: Julien Chaffraix <jchaffraix@google.com>
Cc: "Tab Atkins Jr." <jackalmage@gmail.com>, www-style list <www-style@w3.org>, Ojan Vafai <ojan@chromium.org>
On Tue, Jun 18, 2013 at 1:56 PM, Julien Chaffraix <jchaffraix@google.com> wrote:
> Actually I would rather see the specification mature before we
> unprefix these properties for several reasons:
>
> * align-self has 2 incompatible grammars:
> Alignment: auto | [ baseline | head | foot | center | stretch ] && true?

I'm not sure where you got that from...? The alignment spec says:
http://dev.w3.org/csswg/css-align/#align-self-property
Name:align-self
Value:auto | stretch | baseline | [ <item-position> && <overflow-position>? ]

And:

<item-position> = center | start | end | self-start | self-end |
                  flex-start | flex-end | left | right;

So the alignment spec has a superset of values for align-self, which
is fine - we'll implement them when we implement the alignment spec.

> Flexbox: auto | flex-start | flex-end | center | baseline | stretch
>
> * The 'true' value is just weird and would be better named something
> more revealing (e.g. force-positioning)

I agree that it is a weird name but I'm not sure that
force-positioning is better. Maybe "true-alignment" vs
"safe-alignment"? That said, since flexbox doesn't use these
properties, and since changing that name is unlikely to affect the
subset that flexbox ships, I'm not sure this should be a blocker.

> * Some properties with the same values (e.g. align-self: auto,
> justify-self: auto) have different behaviors based on the type of
> elements it applies to. This is going to cause confusion when using
> these properties and values.

justify-self: That's just describing behavior that already exists,
except for grid. I'm not sure which thing you're objecting to exactly.
Are you suggesting that grid shouldn't stretch its children by
default...? Or that abs pos elements should also inherit their justify
value from the parent's justify-items?

align-self: I think the spec is wrong here (it's definitely
inconsistent), per section two it only applies to flex/grid, and I
think that makes the most sense. The prose in 5.2 seems wrong in a few
places (some mentions of justify-* in a few places, "Applies To" seems
wrong, and I think the description for abs pos boxes isn't right)

Making it apply to non-flex/grid seems a little weird, for the reason
mentioned in the "Block-level boxes" paragraph.

> * justify-self: auto on grid items just stretches the items. I find
> this weird and I have a hard time understanding what's the use case
> for it: width: auto (the default) gives you the stretch behavior
> already.

justify-self gives you inheritance from the parent. justify-items does
default to stretch. But I think you're assuming a horizontal writing
mode here...

That said I'm not proposing shipping anything for grid, just for flex.

-christian
Received on Tuesday, 18 June 2013 21:38:29 UTC

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