1637536 - Accessibility: Subject field accessible name is never updated after the initial opened mail

Status: RESOLVED FIXED

(Thunderbird :: Mail Window Front End, defect)

Description

[Marco Zehe (:MarcoZ)]

STR:

1. Open TB.
2. Turn off preview pane. I have it turned off because I want messages to stay unread when arrowing onto them, and only get marked read if I open them with Enter.
3. Open the first mail.
   • The accessible name of the mail-headerfield with ID "expandedsubjectBox" receives an accessible name of "Subject: " followed by the actual subject.
4. Close the mail with CTRL+W.
5. Select a different mail and open it.
6. Inspect the accessible name for the subject header field.
   • Expected: The field should read "subject" followed by the new subject.
   • Actual: The accessible name still shows the subject for the previous mail from step 3.
7. Close and open more e-mails.
   • Result: The accessible name for the subject header field never gets updated.

Other fields such as from and to are not affected by this bug.

I suspect that something in the implementation of bug 1493608 never works beyond the first opened mail.

Setting accessibility severity to 3 in accordance with the Accessibility triage guidelines.

Comment 1

[Magnus Melin [:mkmelin]]

(The implementation was bug 1589859)
Alex, I guess this is because we're re-using these fields and not creating new ones. We could either generate them always, or then we need to store the aria-labelledby value we used before we remove it.

Comment 2

[Marco Zehe (:MarcoZ)]

Again, the other fields work, only the subject field doesn't get updated. Perhaps you need to actually set the aria-labelledby again somewhere once you reuse the field? I tried tinkering with this in msgHeaderView.js, but even if I update the aria-labelledby in both the case of a new or existing field once it is all set up, it doesn't work in my local build.

Comment 3

[Alessandro Castellani [:aleca]]

Thanks for the detailed report.
I'll work on it.

Comment 4

[Alessandro Castellani [:aleca]]

Attachment: 1637536-subject-aria.diff

Apparently, the subject field is not recreated when a new message pane is opened, even if the previous one is closed.
Since we were removing the aria-labelledby attribute to prevent hierarchy issues with the dynamically set aria-label, that attribute wasn't available anymore in any other message panel, therefore the previous value set in the subject aria was remaining.

I fixed the issue by fetching the value from the label[control="id"] element, which we don't need to remove.

The other fields don't present this problem since are dynamically generated.

Comment 5

[Magnus Melin [:mkmelin]]

Comment on attachment 9148102 [details] [diff] [review]
1637536-subject-aria.diff

Review of attachment 9148102 [details] [diff] [review]:
-----------------------------------------------------------------

::: mail/base/content/mailWidgets.js
@@ +47,5 @@
>  
>      set headerValue(val) {
>        // Solve the accessibility problem by manually fetching the translated
>        // string from the label and updating the attribute. Bug 1493608
> +      let label = document.querySelector(`label[control="${this.id}"]`);

I don't know about this. It could be expensive, and there really is (in theory) any requirement the id to be set at all.

@@ -52,5 @@
> -        let ariaLabel = document.getElementById(
> -          this.getAttribute("aria-labelledby")
> -        );
> -        this.setAttribute("aria-label", `${ariaLabel.value}: ${val}`);
> -        this.removeAttribute("aria-labelledby");

I would suggest to here, just stash this on the object before removing the attribute. Like

this._ariaBaseLabel = ariaLabel;

Then check for that attribute and use it as needed next time

Comment 6

[Alessandro Castellani [:aleca]]

Sounds good, thanks for the review and suggestion. I'll fix this right away

Comment 7

[Alessandro Castellani [:aleca]]

Attachment: 1637536-subject-aria.diff

Comment 8

[Magnus Melin [:mkmelin]]

Comment on attachment 9148181 [details] [diff] [review]
1637536-subject-aria.diff

Review of attachment 9148181 [details] [diff] [review]:
-----------------------------------------------------------------

Looks good, thx! r=mkmelin

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/1950b809c989
Fix aria-label not updating the Subject field in the message header. r=mkmelin