Allow additional elements to be considered labelable

[dmjohnsson23]

https://html.spec.whatwg.org/multipage/forms.html#categories

Some elements, not all of them form-associated, are categorized as labelable elements. These are elements that can be associated with a label element.

button, input (if the type attribute is not in the Hidden state), meter, output, progress, select, textarea, form-associated custom elements

It seems to me that there are some additional cases where having an element be labelable would be desirable, namely:

• Any element with contenteditable (these are conceptually user input fields, so it would make sense to allow them to be labeled)
• A <fieldset> (obviously fieldsets have the <legend> element, but for styling it may be desirable to label the fieldset with an element not nested inside the fieldset)
• An element with any widget role

Obviously workarounds exist, such as aria-labeledby, or using custom elements, but it would seem a lot simpler to just be able to use the <label> element already present in HTML.

[alien999999999]

See w3c/html#734 for earlier discussions. IMHO this would be used if it was in spec, but it isn't and so people workaround it.

[AutoSponge]

Label is an interactive element for pointers/touch that focuses the associated interactive element. I'd only be in favor of this IF browser vendors confirm they can support this feature.

Aside from that, <legend> works just fine. Especially considering my above comment, what's the expected behavior of mouse click on a <label> in a <fieldset>? First interactive? First empty?

Lastly, I think contenteditable is really hard to label. Often, it's whatever the user puts in there. And how often do you see a label for this? Personally, never. A tooltip (cringe)/description explaining how to use it, visual affordances that it's editable are all helpful but not getting a lift from <label> unless this is just enabling authors to replace actual proper form elements with <label> + contenteditable in which case I'm against.