Re: [Accessibility-ia2] Mapping of aria-errormessage for ATK/AT-SPI2 and IA2

1. If error message were mapped to description in a11y APIs, the user 
agent can choose to expose it first and only when aria-invalid is true.
2. aria-invalid communicates the state of "urgency". For example, NVDA 
says "invalid entry". I don't think screen readers should provide an 
additional indication for an error message, as that would be redundant, 
but that's an implementation detail, not a spec detail.
3. It occurred to me that one possible annoyance with error message 
being mapped to description is that if both were present, a change in 
one might cause both to be read.
4. We might be able to mitigate the performance concern using the 
invalid state; i.e. we only need to check for error message if invalid 
is set. Joanie, thoughts?

Jamie

On 14/04/2016 7:01 AM, Joseph Scheuhammer wrote:
> On 2016-04-13 11:46 AM, Matt King wrote:
>> When aria-errormessage was first discussed, my understanding was that the purpose is to distinguish an error message from a description so that assistive technologies would have the option to give it special treatment.
>>
>> Is there more to it than that?
> Aria-errormessage is tied to aria-invalid.  The error message is
> relevant only when the input is invalid.  In contrast, descriptions have
> no specific dependency on validity.
>
> Based on that, the error message is presented only when the input is
> invalid.  For a sighted user, the error message is not rendered unless
> or until the user has input invalid information.  At that point the
> error message is shown near or "attached" to the invalid input.  If the
> user corrects the input, the error message vanishes, thereby providing
> reinforcement that the error has been corrected.  On the other hand, the
> description is presented on demand -- for example, as a tooltip when the
> user mouses over the control.  A corollary is that the error message
> conveys a sense of urgency or obligation -- something needs to be fixed
> -- whereas the description does not.
>

-- 
James Teh
Executive Director, NV Access Limited
Ph +61 7 3149 3306
www.nvaccess.org
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SIP: jamie@nvaccess.org

Received on Wednesday, 13 April 2016 22:28:39 UTC