bug(a11y): assertive toast not announced

[DavideMininni-Fincons]

Prerequisites

• I have read the Contributing Guidelines.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already report this problem, without success.

Ionic Framework Version

• v4.x
• v5.x
• v6.x
• Nightly

Current Behavior

The toast message in not announced by screenreaders even with aria-live='assertive'.

Tested with:

• Ionic 6.2.4
• NVDA 2022.2.2 on Chrome and Firefox
• JAWS 2022.2207.25 ILM on Chrome and Firefox

Expected Behavior

According to ARIA live regions spec:

aria-live="assertive" should only be used for time-sensitive/critical notifications that absolutely require the user's immediate attention. Generally, a change to an assertive live region will interrupt any announcement a screen reader is currently making. As such, it can be extremely annoying and disruptive and should only be used sparingly.

So I expect assertive toast message to be announced when toast is shown.

Steps to Reproduce

• Checkout v.6.2.4
• npm install in ./core
• npm start
• go to http://localhost:3333/src/components/toast/test/a11y using Chrome/Firefox
• launch NVDA/JAWS
• click on 'Present Assertive Toast'
• no announcement

I could provide a demo app using @ionic/angular, but I need to test the toast behaviour with JAWS (with NVDA on Chrome/Firefox is not working).

Code Reproduction URL

No response

Ionic Info

[WARN] You are not in an Ionic project directory. Project context may be missing.

Ionic:

Ionic CLI : 5.4.16

Utility:

cordova-res : not installed
native-run : not installed

System:

NodeJS : v14.17.1
npm : 6.14.13
OS : Linux 4.4

Additional Information

No response

[liamdebeasi]

Thanks for the report. So there is an issue here, but it is unrelated to aria-live. Live regions control updates to content. From MDN Live Regions:

aria-live: The aria-live=POLITENESS_SETTING is used to set the priority with which screen reader should treat updates to live regions - the possible settings are: off, polite or assertive. The default setting is off. This attribute is by far the most important.

This means that if you were to update the message a few seconds after the toast was shown, narrators would announce the updated content according to your aria-live preference.

---

However, the issue here is that narrators do not announce toasts when they first appear. This is a bit tricky because a) toasts never receive focus and b) the intent of toasts may differ between use cases.

For toasts that require the user's immediate attention, role="alert" may be appropriate here. This will cause narrators to announce the toasts when they first appear. It also assumes aria-live="assertive" and aria-atomic="true", so narrators will be interrupted and announce the entire toast.

For toasts that do not require the user's immediate attention, role="status" may be appropriate here. This role assumes aria-live="polite" and aria-atomic="true". However, NVDA does not announce the toast when the toast is initially presented. It seems that the intent is role="status" regions are always present in the DOM.

---

When adding support for #24484, this issue may go away since the overlay element will exist in the DOM ahead of time. However, we should investigate ways of solving this when using controller toasts too.

[DavideMininni-Fincons]

Hi @liamdebeasi, and thank you for your quick answer 🚀

If it could help, I created this repo using the toast controller in an Angular project;
from what I could see, the two toasts triggered during onInit are announced only by JAWS on Firefox (maybe confirming what you said about first apparition?).
Toasts spawn by buttons click behave randomly - NVDA on Firefox never announce them, NVDA on Chrome and JAWS does it many times but not always.

Probably I could confirm what you said about #24484: in a pure JS environment, if I generate a div with aria-live attribute set, append it to body and then append the toast inside it, message is always announced.

[liamdebeasi]

Thanks for the report. I was able to fix the NVDA announcement issue in #27198. I did more research into how toasts should be used as part of this work. I discovered that toasts should only use polite presentation (Material Design spec for reference: https://m2.material.io/components/snackbars/web#accessibility). As a result, I also have a PR to update the docs that notes this: ionic-team/ionic-docs#2914.

This fix should be available in an upcoming release of Ionic. Let me know if you have questions.

[ionitron-bot]

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