Re: aria-labelledby and recursion

Apparently Firefox doesn't unwind recursive relation attributes and this
goes with the alg we follow [1]. I don't recall a decision background, but
I think that was done to keep things simple.

[1]
http://asurkov.blogspot.ca/2012/11/accessilbe-firefox-text-equivalent.html

On Wed, Apr 29, 2015 at 2:44 PM, Dominic Mazzoni <dmazzoni@google.com>
wrote:

> Is aria-labelledby supposed to be allowed to be used recursively? For
> example:
>
> <input aria-labelledby="label1">
> <div id="label1" aria-labelledby="label2">Label 1</div>
> <div id="label2">Label 2</div>
>
> Is the computed name of the input element supposed to be Label 1 or Label
> 2? I thought it was supposed to be Label 2, but the spec (
> http://www.w3.org/TR/accname-aam-1.1/) says:
>
> "Otherwise, if the current node has a non-empty aria-labelledby attribute,
> and the current node is not already part of an aria-labelledby traversal,
> process its IDREFs in the order they occur:"
>
> That seems to imply that when you're part of an aria-labelledby traversal,
> you stop following the aria-labelledby attribute. Is that true, or is it
> misworded?
>
> Here's an even more subtle example:
>
> <input aria-labelledby="label1">
> <div id="label1">
>   Enter your
>     <img src="visa.png" aria-labelledby="visa">
>   or
>     <img src="mastercard.png" aria-labelledby="mastercard">
>   credit card number now.
> </div>
> <div hidden id="visa">Visa</div>
> <div hidden id="mastercard">Mastercard</div>
>
> I think as a web developer I'd be really surprised if the text for the
> label element itself was "Enter your visa or mastercard credit card number
> now" but the computed label for the input element was "Enter your or credit
> card number now" because aria-labelledby is not allowed to be followed
> recursively.
>
>