RE: Question in the use of aria-hidden attribute

Ø  I agree with removing the attribute. Even better, avoid using it at all unless there is literally no other way to achieve a good result.

So could we then say that not using aria-hidden true for background page content in general when a modal dialog is open would be WCAG conformant?  I have always been hesitant to require aria-hidden with modals because of the points raised in this discussion.  I understand that if the DOM was arranged correctly with the dialog as a sibling to the rest of the page content then aria-hidden could be used safely.  I also understand that some screen readers will hide the rest of the content from the user when aria-modal true is used - although the support for this is limited and problematic on iOS with VoiceOver.

But based on the discussion it would be helpful to get consensus that if a modal dialog was created otherwise correctly and tab focus was restricted, a missing aria-hidden true on the rest of the page would not trigger a WCAG failure.

Jonathan


From: Matt King [mailto:a11ythinker@gmail.com]
Sent: Wednesday, December 05, 2018 2:12 AM
To: Bryan Garaventa; 'Sean Murphy (seanmmur)'; w3c-wai-ig@w3.org
Subject: RE: Question in the use of aria-hidden attribute

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I agree with removing the attribute. Even better, avoid using it at all unless there is literally no other way to achieve a good result.

Aria-hidden="true" is extremely dangerous. If you think you need to use it, which you probably do not, test, test, and over test. Then, put in some kind of redundant test plan.

Right now, there are several sites, including dropbox and 1password,  where opening a modal completely breaks the site because they thought using aria-hidden was a good idea. The risk of using aria-hidden to hide content under a modal is not offset by the benefits most people assume. If the dialog is a DOM descendant of the content at a lower z, then everything breaks for screen reader users. You can do nothing; you are dead in the water.

Matt King

From: Bryan Garaventa <bryan.garaventa@levelaccess.com>
Sent: Monday, December 3, 2018 9:17 AM
To: Sean Murphy (seanmmur) <seanmmur@cisco.com>; w3c-wai-ig@w3.org
Subject: RE: Question in the use of aria-hidden attribute

Historically aria-hidden="false", when set explicitly, was supposed to expose a hidden container such as one that used the hidden attribute or CSS display:none so that it would be exposed to screen reader users regardless.

This was like a total inversion of the visual state, where it would be hidden visually but exposed to screen reader users like offscreen text.

In practice however this was never supported by Firefox, and was exposed by JAWS in IE11, and as a result has never worked reliably and has caused major problems when the exposed container included active elements like links and buttons, that, even when exposed, are completely inaccessible in this state. This has led to critical accessibility issues occurring in enterprise applications as a result of these discrepancies.

Developers should always avoid setting aria-hidden="false" on anything just to be safe. Removing the attribute altogether is best in most cases.



Bryan Garaventa
Principle Accessibility Architect
Level Access, Inc.
Bryan.Garaventa@LevelAccess.com<mailto:Bryan.Garaventa@LevelAccess.com>
415.624.2709 (o)
www.LevelAccess.com<http://www.LevelAccess.com>

From: Sean Murphy (seanmmur) <seanmmur@cisco.com<mailto:seanmmur@cisco.com>>
Sent: Sunday, December 02, 2018 9:09 PM
To: w3c-wai-ig@w3.org<mailto:w3c-wai-ig@w3.org>
Subject: Question in the use of aria-hidden attribute

All,

I have seen discussions on  the use of aria-hidden attribute. I am still not 100% sure on the correct usage after reading the relevant documentation.

Aria-hidden="true" - from the current block attribute (tag) and children are removed from the accessibility tree. visually, is the information still present if no CSS attributes used?
Aria-hidden="off" - does nothing to the accessibility tree.
Now for aria-hidden="false". Extracted code below (assume CSS attributes are not hiding the content).

    <div id="main" role="document" aria-hidden="false">
</div>

What would occur with the children tags within the above div? would they still be visible to the accessibility tree?

Sean