How should I announce validation errors via platform screen readers?

[TDuffinNTU]

Resource URL

https://www.w3.org/WAI/tutorials/forms/validation/

Description

Working on a flutter application, but this should be applicable for all platforms. We have validation errors that show up when the user attempts to submit a invalid form, or if they've missed something - How should screen readers such as Talkback, Voiceover, etc. handle these?

Options I've considered:

1. Focus first invalid field, announce one (1) error only.
2. Focus first invalid field, announce all (n) errors in order.
3. Focus last invalid field, announce one (1) error only.
4. Focus last/first invalid field, announce no errors.
5. Focus last/first invalid field, show and focus a snackbar/error dialog.

It would be good to know what the "best practice" is so we can redesign the application around them, and assert that Flutter's framework meets these requirements. Thank you!

Resource Shortname

wai-tutorials