Specify behavior when following a hidden subtree via aria-labelledby …

[jaragunde]

…or -describedby.

This proposal tries to bring the spec closer to the actual behavior of the different user agents. In general, user agents expose hidden content when following an aria-labelledby or -describedby relation into a hidden subtree. There are differences between engines, though.

This is a summary of what user agents will need to change to comply with this text update:

• Firefox in generally compliant with the proposed wording, but it might need checking for special cases.
• Chrome would need to change the behavior for aria-hidden. Example:

  <style>.hidden {display:none;}</style>
  <input id="el1" role="button" aria-labelledby="el2" />
  <span id="el2" class="hidden">
  <span id="el3" aria-hidden="true">hello</span>
  </span>

  Name for the input should be "hello", currently empty in Chrome.

• WebKit would need to unify behavior between different types of hidden, because it currently produces different names when using display:none and visibility:hidden. Example:

  <style>.hidden {visibility:hidden;}</style>
  <input id="el1" role="button" aria-labelledby="el2" />
  <span id="el2" class="hidden">
  <span id="el3" class="hidden">hello</span>
  </span>

  Name for the input should be "hello", currently empty in WebKit. It would be "hello" if display:none was used instead.

Thanks in advance for your time and feedback.

Closes #57.

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Preview | Diff

[jaragunde]

I've setup my account as requested, feel free to "revalidate". Thanks!

[MelSumner]

I'm looking at these use cases in a CodePen, apologies for the review delay.

[jaragunde]

@jcsteh: Exactly, that's the difference between the previous wording and the new one.

[jaragunde]

@MelSumner: thanks for the CodePen, it's very useful!

[MelSumner]

Not sure why it was marking some changes as conflicted, but I think they are resolved now.

[jnurthen]

@MelSumner I thought we were waiting for @cookiecrook and @cyns reviews

[cookiecrook]

@MelSumner I thought we were waiting for @cookiecrook and @cyns reviews

Merging provides additional motivation. 🤣

[jaragunde]

Thanks for the review, I definitely agree with all your suggestions, some are even mistakes on my side caused by writing over and over.

To be more clear, I cannot think of a better suggestion for "root of the traversal". I would agree to revert it back to the term originally used, and keep track of what it means and how to enhance it in #148.