RE: Regarding discrepancy for ARIA sliders

Bryan,

Here is the APG design pattern for multi-thumb slider that includes guidance for using aria-valuenow:
https://w3c.github.io/aria-practices/#slidertwothumb

In the ARIA Specification the  aria-valuenow attribute is required for the "slider" role, see authors "MUST set the aria-valuenow attribute":
https://w3c.github.io/aria/#slider

From a practical point of view aria-valuenow needs to be defined since some browser and assistive technology combinations, especially legacy technology, ignore aria-valuetext and present the slider as a percentage.  If there is no aria-valuenow value, then no percentage.

Jon


From: Bryan Garaventa <bryan.garaventa@levelaccess.com>
Sent: Tuesday, April 27, 2021 12:01 PM
To: public-aria-practices@w3.org; Accessible Rich Internet Applications Working Group <public-aria@w3.org>
Subject: Regarding discrepancy for ARIA sliders

Hi,
We had a customer question our flagging of an element role=slider being for lack of an aria-valuenow. Their slider is a double-thumb one for specifying a low and high value. Instead of an aria-valuenow they specify an aria-valuetext="From 27 to 48" or whatever the two thumbs are set to. It seems that

https://www.w3.org/TR/wai-aria-1.2/#slider<https://urldefense.com/v3/__https:/www.w3.org/TR/wai-aria-1.2/*slider__;Iw!!DZ3fjg!va21MZlLvZNSWwLgdjOpDjT8C4Gey0WfYUFYqgk1kquQEqFOcviIBw-iEboUoO-DeA$>

contradicts

https://www.w3.org/TR/wai-aria-practices-1.2/#slider<https://urldefense.com/v3/__https:/www.w3.org/TR/wai-aria-practices-1.2/*slider__;Iw!!DZ3fjg!va21MZlLvZNSWwLgdjOpDjT8C4Gey0WfYUFYqgk1kquQEqFOcviIBw-iEbpjPnTEpw$>

The first clearly says

Authors MUST set the aria-valuenow<https://urldefense.com/v3/__https:/www.w3.org/TR/wai-aria-1.2/*aria-valuenow__;Iw!!DZ3fjg!va21MZlLvZNSWwLgdjOpDjT8C4Gey0WfYUFYqgk1kquQEqFOcviIBw-iEbprjyI0Xg$> attribute.

and that a missing aria-valuenow can trigger browser repair techniques. While the second says

"If the value of aria-valuenow is not user-friendly, e.g., the day of the week is represented by a number, thearia-valuetext<https://urldefense.com/v3/__https:/www.w3.org/TR/wai-aria-1.2/*aria-valuetext__;Iw!!DZ3fjg!va21MZlLvZNSWwLgdjOpDjT8C4Gey0WfYUFYqgk1kquQEqFOcviIBw-iEbrduuqXMQ$> property is set to a string that makes the slider value understandable, e.g., "Monday".

So basically, which is it? Should aria-valuenow be a soft requirement or a hard one from the perspective of conformance checkers?

Thanks,
Bryan



Bryan Garaventa
Principal Accessibility Architect
Level Access, Inc.
Bryan.Garaventa@LevelAccess.com<mailto:Bryan.Garaventa@LevelAccess.com>
415.624.2709 (o)
www.LevelAccess.com<https://urldefense.com/v3/__http:/www.levelaccess.com/__;!!DZ3fjg!va21MZlLvZNSWwLgdjOpDjT8C4Gey0WfYUFYqgk1kquQEqFOcviIBw-iEbo9WXe5kA$>