Specify behavior when following a hidden subtree via aria-labelledby … #150

jaragunde · 2022-03-15T09:34:19Z

…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.

Preview | Diff

…or -describedby.

jaragunde · 2022-03-15T09:41:21Z

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

accdc

Personally I like it and approve. Pending review by @MelSumner and @cookiecrook of course. Hopefully we can discuss this at the next meeting to finally get this pulled in.

MelSumner · 2022-03-24T17:50:27Z

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

jcsteh

This looks good to me. I always find this spec hurts my brain a lot and it takes me forever to figure out what behaviour exactly is changing. 😳 For the sake of absolute clarity, I assume the first example you've added demonstrates the difference between the previous and proposed new behaviours? With the previous behaviour (as specified), the label for element1 would be empty because element3 is hidden and not directly referenced.

index.html

jaragunde · 2022-03-31T08:19:35Z

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

jaragunde · 2022-03-31T08:22:23Z

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

MelSumner

seems like we are agreed on these changes, thank you for the submission.

MelSumner · 2022-04-20T14:15:25Z

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

@MelSumner

…review SHA: 3419bd8 Reason: push, by @MelSumner Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

jnurthen · 2022-04-20T16:09:48Z

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

cookiecrook

Mostly editorial with a few clarity questions. Overall I think it makes sense.

Since this is already merged, I could file a separate Issue/PR after we settle on a replacement or clarification for "root of the traversal"…

cookiecrook · 2022-04-21T18:05:09Z

index.html

-            <li id="step2A">If the <code>current node</code> is <a class="termref">hidden</a> <strong>and is not</strong> directly referenced by <code>aria-labelledby</code> or <code>aria-describedby</code>, nor directly referenced by a native host language text alternative [=element=] (e.g. <code>label</code> in HTML) or [=attribute=], return the empty string.
+            <li id="step2A">If the <code>current node</code> is <a class="termref">hidden</a> <strong>and is</strong>:
+            <ul>
+              <li><strong>Not</strong> part of an <code>aria-labelledby</code> or <code>aria-describedby</code> traversal, where the node directy referenced by that relation was hidden.</li>


Last two words ("was hidden") seem to imply either transiency (e.g. element is no longer hidden) or that the element was the direct target of the hiding (e.g. this specific element is the actually hidden node rather than being hidden as a side effect of a hidden ancestor).

Perhaps "is hidden" would be better here, since I understand the intent to be "currently hidden" and we don't care why/how it was hidden? If I'm misunderstanding, more clarification of the intent would be helpful.

I can't add a diff suggestion. Perhaps because it's already merged?

Perhaps "is hidden" would be better here, since I understand the intent to be "currently hidden" and we don't care why/how it was hidden?

Exactly this, I was not trying to express anything different. I should have used the present tense as in the original.

cookiecrook · 2022-04-21T18:06:07Z

index.html

+            <li id="step2A">If the <code>current node</code> is <a class="termref">hidden</a> <strong>and is</strong>:
+            <ul>
+              <li><strong>Not</strong> part of an <code>aria-labelledby</code> or <code>aria-describedby</code> traversal, where the node directy referenced by that relation was hidden.</li>
+              <li><strong>Nor</strong> part of a native host language text alternative <a class="termref">element</a> (e.g. <code>label</code> in HTML) or <a class="termref">attribute</a> traversal, where the root of that traversal was hidden.</li>


ditto

- was hidden + is hidden

"where the root of that traversal" may also be ambiguous.

In this case, is "root" referring to the element labeled by this host language text alternative (e.g. an <input> labeled by <label> that is somewhere inside the overall computation)? Or is this referring to the root of the entire name computation traversal? I think the former because there may not be a time when a hidden node can be the root of the overall computation.

I labored over a diff for a few minutes but this may be similarly confusing. Sharing anyway as a straw man example.

- where the root of that traversal + where the element referenced by the host language text alternative

is "root" referring to the element labeled by this host language text alternative ...?

Yes, that was my intention with that wording. I find the proposed diff fitting, it reuses the terminology used by the original wording which is more appropriate, although it's confusing in the same sense as the original was.

There is already an open issue about this: #148

cookiecrook · 2022-04-21T18:24:43Z

index.html

+                <ul>
+                  <li>Nodes with CSS properties <code>display:none</code>, <code>visibility:hidden</code>, <code>visibility:collapse</code> or <code>content-visibility:hidden</code>: They are considered hidden, as they match the guidelines "not perceivable" and "explicitly hidden".</li>
+                  <li>Nodes with CSS properties <code>opacity:0</code> or <code>filter:opacity(0%)</code>, or similar SVG mechanisms: They are not considered hidden. Text hidden with these methods can still be selected or copied, and user agents still expose it in their accessibility trees.</li>
+                  <li>Nodes with the <code>aria-hidden="true"</code> property: it is considered hidden, matching the "explicitly hidden" guideline.</li>


Editorial nits to match the other lines:

- it is + They are

There is also a mix of casings in They/they on lines 282–285. I don't have a case preference other than consistency.

cookiecrook · 2022-04-21T18:26:56Z

index.html

+                  <li>Nodes with CSS properties <code>display:none</code>, <code>visibility:hidden</code>, <code>visibility:collapse</code> or <code>content-visibility:hidden</code>: They are considered hidden, as they match the guidelines "not perceivable" and "explicitly hidden".</li>
+                  <li>Nodes with CSS properties <code>opacity:0</code> or <code>filter:opacity(0%)</code>, or similar SVG mechanisms: They are not considered hidden. Text hidden with these methods can still be selected or copied, and user agents still expose it in their accessibility trees.</li>
+                  <li>Nodes with the <code>aria-hidden="true"</code> property: it is considered hidden, matching the "explicitly hidden" guideline.</li>
+                  <li>Nodes hidden off screen or behind another object: they are not considered hidden. They are exposed in the accessibility tree and they can even name on-screen objects.</li>


- Nodes hidden off screen + Nodes positioned off screen

- and they can even name on-screen objects. + and can label visible elements.

cookiecrook · 2022-04-21T18:30:39Z

index.html

              <div><details>
                <summary>Comment:</summary>
                <p>By default, <a class="termref">assistive technologies</a> do not relay hidden information, but an author can explicitly override that and include hidden text as part of the <a class="termref">accessible name</a> or <a class="termref">accessible description</a> by using <code>aria-labelledby</code> or <code>aria-describedby</code>. </p>
              </details></div>
+              <div><details>
+                <summary>Example:</summary>
+                <p>The following examples show the meaning of the clause "Not part of an <code>aria-labelledby</code> or <code>aria-describedby</code> traversal, where the node directy referenced by that relation was hidden.".</p>


- was hidden + is hidden

cookiecrook · 2022-04-21T18:42:11Z

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

Merging provides additional motivation. 🤣

jaragunde · 2022-04-22T08:04:05Z

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.

This is an update in the spec: w3c/accname#150 When an aria-labelledby or aria-describedby relation points to a node which is hidden all its nodes will be exposed, including aria-hidden nodes. Chrome previously did exclude aria-hidden nodes in the situation described above. This change aligns the different user agent implementations. Finally, we keep some corrections in place to assign names to aria- -hidden content that can be focused. These corrections are now explicit in the code, when they used to be implicit. Bug: 1330931 Change-Id: Ib5186772a989838010d1bbafc9600827acd29c3b AX-relnotes: name computation: match spec for aria-hidden behavior Cq-Include-Trybots: luci.chromium.try:linux-blink-web-tests-force-accessibility-rel Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3689418 Reviewed-by: Aaron Leventhal <aleventhal@chromium.org> Auto-Submit: Jacobo Aragunde Pérez <jaragunde@igalia.com> Commit-Queue: Aaron Leventhal <aleventhal@chromium.org> Cr-Commit-Position: refs/heads/main@{#1031522}

This is an update in the spec: w3c/accname#150 When an aria-labelledby or aria-describedby relation points to a node which is hidden all its nodes will be exposed, including aria-hidden nodes. Chrome previously did exclude aria-hidden nodes in the situation described above. This change aligns the different user agent implementations. Finally, we keep some corrections in place to assign names to aria- -hidden content that can be focused. These corrections are now explicit in the code, when they used to be implicit. Bug: 1330931 Change-Id: Ib5186772a989838010d1bbafc9600827acd29c3b AX-relnotes: name computation: match spec for aria-hidden behavior Cq-Include-Trybots: luci.chromium.try:linux-blink-web-tests-force-accessibility-rel Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3689418 Reviewed-by: Aaron Leventhal <aleventhal@chromium.org> Auto-Submit: Jacobo Aragunde Pérez <jaragunde@igalia.com> Commit-Queue: Aaron Leventhal <aleventhal@chromium.org> Cr-Commit-Position: refs/heads/main@{#1031522} NOKEYCHECK=True GitOrigin-RevId: d29e6ca63942ee8d96c63c856ad61904191ae0cc

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

3efa7de

…or -describedby.

jaragunde mentioned this pull request Mar 15, 2022

Specify behavior when following a hidden subtree via aria-labelledby … jaragunde/accname#1

Closed

aleventhal requested review from accdc, cookiecrook and jnurthen March 15, 2022 14:13

MelSumner self-requested a review March 16, 2022 21:50

accdc approved these changes Mar 17, 2022

View reviewed changes

jcsteh approved these changes Mar 31, 2022

View reviewed changes

index.html Outdated Show resolved Hide resolved

Use 'Conversely'

e30a74d

cyns self-assigned this Apr 7, 2022

cyns self-requested a review April 7, 2022 17:40

MelSumner approved these changes Apr 20, 2022

View reviewed changes

Merge branch 'main' into hidden-labelledby-subtree-for-review

128349a

MelSumner merged commit 3419bd8 into w3c:main Apr 20, 2022

cookiecrook reviewed Apr 21, 2022

View reviewed changes

Jym77 mentioned this pull request Oct 7, 2022

Name from aria-labelledby should accept aria-hidden descendant of an aria-hiddenreference Siteimprove/alfa#1236

Closed

Jym77 mentioned this pull request Nov 10, 2022

accname-aam clarify hidden #30

Open

This was referenced Oct 13, 2023

Task: verify review feedback from PR 150 made it in #210

Open

Ambiguous but normative requirement about hidden nodes is hidden by default in AccName #211

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Specify behavior when following a hidden subtree via aria-labelledby … #150

Specify behavior when following a hidden subtree via aria-labelledby … #150

jaragunde commented Mar 15, 2022 •

edited by pr-preview bot

Loading

jaragunde commented Mar 15, 2022

accdc left a comment

MelSumner commented Mar 24, 2022

jcsteh left a comment

jaragunde commented Mar 31, 2022

jaragunde commented Mar 31, 2022

MelSumner left a comment

MelSumner commented Apr 20, 2022

jnurthen commented Apr 20, 2022

cookiecrook left a comment

cookiecrook Apr 21, 2022

jaragunde Apr 22, 2022

cookiecrook Apr 21, 2022

cookiecrook Apr 21, 2022

jaragunde Apr 22, 2022

cookiecrook Apr 21, 2022 •

edited

Loading

cookiecrook Apr 21, 2022

cookiecrook Apr 21, 2022

cookiecrook Apr 21, 2022 •

edited

Loading

cookiecrook commented Apr 21, 2022

jaragunde commented Apr 22, 2022

Specify behavior when following a hidden subtree via aria-labelledby … #150

Specify behavior when following a hidden subtree via aria-labelledby … #150

Conversation

jaragunde commented Mar 15, 2022 • edited by pr-preview bot Loading

jaragunde commented Mar 15, 2022

accdc left a comment

Choose a reason for hiding this comment

MelSumner commented Mar 24, 2022

jcsteh left a comment

Choose a reason for hiding this comment

jaragunde commented Mar 31, 2022

jaragunde commented Mar 31, 2022

MelSumner left a comment

Choose a reason for hiding this comment

MelSumner commented Apr 20, 2022

jnurthen commented Apr 20, 2022

cookiecrook left a comment

Choose a reason for hiding this comment

cookiecrook Apr 21, 2022

Choose a reason for hiding this comment

jaragunde Apr 22, 2022

Choose a reason for hiding this comment

cookiecrook Apr 21, 2022

Choose a reason for hiding this comment

cookiecrook Apr 21, 2022

Choose a reason for hiding this comment

jaragunde Apr 22, 2022

Choose a reason for hiding this comment

cookiecrook Apr 21, 2022 • edited Loading

Choose a reason for hiding this comment

cookiecrook Apr 21, 2022

Choose a reason for hiding this comment

cookiecrook Apr 21, 2022

Choose a reason for hiding this comment

cookiecrook Apr 21, 2022 • edited Loading

Choose a reason for hiding this comment

cookiecrook commented Apr 21, 2022

jaragunde commented Apr 22, 2022

jaragunde commented Mar 15, 2022 •

edited by pr-preview bot

Loading

cookiecrook Apr 21, 2022 •

edited

Loading

cookiecrook Apr 21, 2022 •

edited

Loading