Re: aria-labelledby and recursion

Yeah, that's what I observed too when testing Firefox. Firefox doesn't
recursively follow aria-labelledby in either my first or my second example.

If it was intended that the second example should return "Enter your visa
or mastercard credit card number now", then we should fix that in the spec.
If we do that then I really don't understand why we wouldn't allow
recursively following aria-labelledby in my first example too. Why make a
distinction?

If we don't intend for either case of recursion (i.e. we're happy with what
Firefox does now), then the spec is basically correct and could just be
clarified. I'd suggest that we fix the ARIA spec too so that web developers
who read the spec for aria-labelledby understand that it does not get
followed recursively.


On Wed, Apr 29, 2015 at 11:59 AM, Alexander Surkov <
surkov.alexander@gmail.com> wrote:

> 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.
>>
>>
>