Re: dir=auto makes no sense for descendant user-visible attributes

On Wed, Feb 22, 2012 at 10:04 AM, Aharon (Vladimir) Lanin <aharon@google.com
> wrote:

> While working out the semantics of dir=auto, we forgot to deal with how it
> should interact with user-visible attributes like title, alt, and
> placeholder (as well as the value attribute on <input> elements of type
> text, search, button, submit, and reset).
>
> Currently, the HTML5 spec says that all attribute values must be displayed
> to the user in the directionality of the element to which the belong. The
> spec gives no way to specify the directionality of attributes when it must
> differ from that of the element itself (except by using LRE, RLE, and PDF).
> Nor does it give a way to specify that an attribute must be displayed in
> its own estimated direction. This situation, which was already painful with
> placeholder (see https://www.w3.org/Bugs/Public/show_bug.cgi?id=15488)
> becomes insufferable when the user-visible attribute is on an element with
> dir=auto or a descendant of one, since the directionality of an element
> with dir=auto is chosen on the basis of descendant text nodes and is
> completely unrelated to the value of the attributes in its scope of
> influence.
>
> I am looking for ideas on how to fix this.
>
> One possibility is to divorce user-visible attributes from their elements'
> directionality completely, always estimating the directionality of each
> attribute by its content. This suffers from backwards compatibility
> problems (since estimation is a heuristic that sometimes gives the wrong
> answer).
>
> A better possibility is to divorce it only for elements under the
> influence of dir=auto. Thus, if an element has dir=auto (explicitly or
> implicitly, the latter being the case for <bdi>), each of the attributes in
> the subrtree rooted at that element, with the exception of elements
> specifying dir="ltr" or dir="rtl" and their descendants, must be displayed
> to the user as if they had a dir=auto of heir own.
>

I like the second proposal better.  Although I have to say that it has been
worded a bit vaguely.  What I have in mind is for the title attribute in
the following example to have a resolved RTL direction:

<p dir="auto" title="RTL TEXT followed by ltr text">ltr text FOLLOWED BY
RTL TEXT</p>

Cheers,
--
Ehsan
<http://ehsanakhgari.org/>