Map maxlength

[aardrian]

Currently the HTML maxlength attribute on a text input is not mapped to any accessibility APIs.

Visually this may not be an issue for a sighted user as they will see no more characters are accepted in a field.

But for a screen reader user, since this attribute is not exposed there is no way for a screen reader user to know there is a limit nor that they may have exceeded (short of exiting and re-entering the field to confirm the entered text).

While aria-valuemax is scoped to range/slider-ish controls, and while it speaks to a value rather than a character count, this may be a basis worth exploring. AT could recognize the context of a text field and evaluate it as a character limit. Hat tip to @stevefaulkner for the suggestion.

[aardrian]

And I see there is discussion at the ARIA spec for a dedicated property (thanks @scottaohara):
w3c/aria#1119