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Re: [css-align][css-flexbox] conflicting propdefs for alignment properties

From: fantasai <fantasai.lists@inkedblade.net>
Date: Wed, 01 Apr 2015 22:51:08 -0400
Message-ID: <551CAE9C.1050607@inkedblade.net>
To: www-style@w3.org
Please, in general, put a topic in the subject line in addition to the spec tags? :)

On 04/01/2015 07:49 AM, Javier Fernandez wrote:
> Last version of CSS Flexbox specification still defines the align-self,
> align-items, justify-content and align-content properties independently
> of the new CSS Box Alignment specification. However, the Alignment
> section headline makes a explicit reference to this spec in order to
> define the alignment behavior for Flexbox. This situation causes some
> contradictions, or at least, misunderstandings of what values are valid
> and what not for Flexbox.
[...]
> First of all, I think it's confusing to state that Flexbox spec "respect
> the alignment properties from CSS Box Alignment" and then re-define
> those properties with a subset of the allowed values and a different
> initial and computed values behavior.
>
> The most problematic case is 'start' as initial value, since it'd
> declared as invalid when using as reference just the Flexbox
> specification. The Flexbox item's align-items property will be resolved
> to 'start' when using the 'auto' value as initial, according to the Box
> Alignment specification, however, this is not a valid value according to
> the Flexbox specification.
>
> I think one way to solving these conflicts and avoid confusion would be
> to just rely all the Flexbox Alignment behavior to the Box Alignment
> specification, as the Gird Layout spec already does.
>
> I understand that Box Alignment specification is not as stable and
> Flexbox, but I wonder about the plans for the future regarding its
> integration with the Flexbox spec.

Flexbox was shipped first, with a subset of the functionality in the
Alignment spec. To comply with Flexbox, you must implement at least
those properties and values.

Wrt the initial value change; this is expected to be an invisible
change to authors.

An implementation that implements both specs would use the Box
Alignment definitions, which supersede Flexbox's definitions.
(I'll clarify that in the module interactions section.)

~fantasai
Received on Thursday, 2 April 2015 02:51:40 UTC

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