Specify what should happen when unhiding an ancestor of a live region

[mitchellevan]

With each of the structures below, what should happen?

1. Load a page with one of the structures below
2. Unhide the parent container

Structure 1: unhiding visually

<div style="display:none;"> <-- e.g., inside a disclosure widget -->
  <div aria-live="polite">chat message: hello</div>
</div>

Structure 2: unhiding from assistive technology

<div aria-hidden="true"> <-- e.g., behind a dialog -->
  <div aria-live="polite">chat message: hello</div>
</div>

Browsers are currently inconsistent. aria-live example with test results

The consequence of the inconsistency is that aria-live is difficult to use on visible content, like a chat log, when combined with other common widgets in the same page such as a disclosure widget or a dialog.

If Core AAM is not the right place for this issue, please let me know.

[JAWS-test]

Related w3c/aria-practices#78, w3c/aria#1854

I have come to share the assumptions you made on your test page as a basis for evaluating screen reader output, even though I wrote otherwise years ago in the linked issues

[jnurthen]

closing in favour of the aria issue w3c/aria#1937