HTML-AAM: how to map Inner Phrasing Content for <meter>?

[jasonkiss]

From @cyns on February 2, 2016 18:24

HTML spec on has examples like this

<meter value="0.5">Moderate activity</meter>

Where should the inner phrasing content "Moderate activity" be mapped in the AAPIs? Is this a value? Part of name or description? Something else?

Copied from original issue: w3c/aria#240

[jasonkiss]

From @cyns on April 23, 2016 21:9

@stevefaulkner @jasonkiss @joanmarie we're blocked on this one. should it be mapped at all?

I thought about mapping it to aria-valuetext, but that uses the same uia property that we're using for the result of optimal calculation (Value.Value).
The fallback content doesn't seem like it would make a good name.

[jasonkiss]

From @cyns on April 23, 2016 21:22

#334 is related

[jasonkiss]

My initial impression is that the element subtree would be used for the accname. So similar to how button gets its name computed.

But I note that meter (and button and output for that matter) is a labelable element that can also have a phrasing content subtree.

So wouldn't the name computation be the following?

1. Use aria-label or aria-labelledby if provided
2. associated label element if provided
3. content subtree
4. title attribute

And if so, should we also update the name computation for button and "Other Form Elements" to account for potential use of label and/or element subtree if applicable? @stevefaulkner? This should probably be followed up on in issue #29.

Regardless, given that final mappings for meter (see issue #2) have been deferred to AAM v2, I think it makes sense to do the same with this one.

[asurkov]

confirming: the sequence looks reasonable, and shouldn't be different from HTML:button one.

However I would say instead that elements like HTML:button are labellable and allow name computation from subtree leaving ARIA behind, since this is universal rule and we don't have to repeat it all over.

[jasonkiss]

Thanks, @asurkov. I've carried on the conversation over at #29.

[jcsteh]

@jasonkiss commented on Feb 7, 2018, 9:50 AM GMT+10:

My initial impression is that the element subtree would be used for the accname. So similar to how button gets its name computed.

I don't really follow this. Yes, button is similar in that it can have content, but the similarity ends there. Button's content is visible to all users. In contrast, meter's content is fallback content. If anything, fallback content is more likely to be a textual representation of the value. An author is likely to do something like this:

<p>Heat the oven to <meter min="200" max="500" value="350">350 degrees</meter>.</p>

rather than this:

<p>Heat the oven to <meter min="200" max="500" value="350">temperature of the oven</meter>.</p>

I'd suggest that aria-valuetext (as discussed above) is a better mapping. I don't quite understand mapping of optimal to value; low, optimal and high seem difficult/impossible to map with current accessible value interfaces.