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[csswg-drafts] Issue: [css-writing-modes-3] Propose to replace "'text-orientation: upright' to cause strong LTR" with author notes how to do it marked as i18n-tracking

From: r12a via GitHub <sysbot+gh@w3.org>
Date: Wed, 30 Nov 2016 09:23:24 +0000
To: www-international@w3.org
Message-ID: <issues.labeled-191436597-None-sysbot+gh@w3.org>
r12a has just labeled an issue for https://github.com/w3c/csswg-drafts
 as "i18n-tracking":

== [css-writing-modes-3] Propose to replace "'text-orientation: 
upright' to cause strong LTR" with author notes how to do it ==
The [`text-orientation: 
upright`](https://drafts.csswg.org/css-writing-modes-3/#valdef-text-orientation-upright)
 has the following text:

> This value causes the used value of direction to be ltr, and for the
 purposes of bidi reordering, causes all characters to be treated as 
strong LTR.

This is a proposal to replace this text with notes for authors.

## Background

In TPAC, we discussed [test 
status](http://kojiishi.github.io/generate-w3c-implementation-report/css-writing-modes-3/status-2016-09.html)
 and this is one of the "Required Tests That Do Not Meet Exit 
Criteria". @fantasai expressed that she is not comfortable to exit CR 
without passing this. Some discussions made there were:

* While this is not needed for joining RTL scripts such as Arabic, it 
does make sense for non-joining RTL scripts such as Hebrew.
* This is considered as extremely rare, the only use case we saw was 
building signage.

I then made further investigations as below to come to this proposal.

## Workaround for authors

Authors can get almost the same effect by the following CSS:

```css
.vertical-upright {
  writing-mode: vertical-rl;
  text-orientation: upright;
  unicode-bidi: override;
  direction: ltr;
}
```

Note, this workaround does not work if it has child elements with 
`dir` attributes, or different values of `unicode-bidi` properties.

## Implementation status

* Blink [crbug.com/663281](http://crbug.com/663281), Edge 
[9713176](https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/9713176/),
 WebKit [wkb.ug/164507](http://wkb.ug/164507) does not implement.
* Gecko [1315892](http://bugzilla.mozilla.org/show_bug.cgi?id=1315892)
 implements partially, by inserting the RLO (the same effect as the 
workaround above) if the block has `text-orientation: upright`.
  - It has the same restriction as above.
  - It does not work when `text-orientation: upright` is applied to 
inline elements.
  - It does not change the used value of `direction`, and therefore 
other effects (e.g., logical properties, table cell orders, etc.) is 
not included.

## Proposal

Given there is an easy workaround for authors, and given 
implementations are very limited, this proposal is to replace the text
 with a note how authors can get this effect.

I'm fine with other options, such as:

* Keep the text as is, by making the test failures as an exception to 
exit criteria.
* Make it "should" or "may".

but after reviewing the workaround and status, it looks to me that 
it's better to let authors know how to do it, rather than keeping the 
text and non-interoperable behavior.

Thoughts?

See https://github.com/w3c/csswg-drafts/issues/755
Received on Wednesday, 30 November 2016 09:23:32 UTC

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