Toolbar module does not follow W3C

This might provide more infos about the aria attribute:

https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA

Critical here is to know if screenreaders use it, whether it's in the spec or not. Accessibility is for people not validators. Once that's confirmed (or not) we can talk about a patch. I know a screenreader user has been involved in the making of toolbar to check accessibility, so it's probably not been added for the fun of it.

Pinged Jesse Beach :) https://twitter.com/wimleers/status/593439139057512448

Dom, thank you for bringing this issue up.

You're right, aria-owned-by doesn't exist in the spec. What we're trying to do here is create a relationship between DOM elements that isn't represented through hierarchy. That relationship should be established with the aria-owns (http://www.w3.org/TR/wai-aria/states_and_properties#aria-owns) attribute on the toolbar button that opens the tab. This code is there, but I believe it's wrong. This is the code now.

$attributes += array(
  'data-toolbar-tray' => $id . '-tray',
  'aria-owns' => $id,
  'role' => 'button',
  'aria-pressed' => 'false',
);

It should be

$attributes += array(
  'data-toolbar-tray' => $id . '-tray',
  'aria-owns' => $id . '-tray',
  'role' => 'button',
  'aria-pressed' => 'false',
);

aria-owns should indicate the ID of the DOM element that this element owns.

Dom, could you update your patch to reflect this?

Tested Dom's patch and the aria-owned-by errors goes away when I run it through the W3C validator.
I've attached a patch with both Dom's and jessebeach's changes included.

Adding missing word to make the title less confusing. :)

Also adding some tags.

PS: Nice to see you again, jessebeach! :D Thanks for stopping by!

Testbot is completely broken today :( We'll have to wait until the DA fixes the testbots…

LGTM.

PPS: Hi webchick!!

Removing w3c tag, the w3c validation seems to be used a little more. w3c alone isn't very clear.

This issue is a normal bug fix, and doesn't include any disruptive changes, so it is allowed per https://www.drupal.org/core/beta-changes. Committed 437fa37 and pushed to 8.0.x. Thanks!