HTML: Allow activation of a checked radio button to clear it

[hjanuschka]

Specification title

HTML: Allow activation of a checked radio button to clear it

Specification or proposal URL (if available)

whatwg/html#12480

Explainer URL (if available)

whatwg/html#12480

Proposal author(s)

@hjanuschka

web-feature id

None.

MDN URL

None.

Caniuse.com URL

None.

Bugzilla URL

Not yet filed.

Mozillians who can provide input

None identified.

WebKit standards-position

WebKit/standards-positions#721

Other information

The proposal changes radio-button activation so that activating the currently checked radio button can return an optional radio group to its no-selection state. If the group has a radio button with a checked content attribute, activation instead restores that author-provided default.

The use case is an optional form question where a user accidentally selects an answer and currently has no native way to return the group to its initial no-selection state. Radio groups already support no selection initially and through script; the proposal makes that state reachable through user activation.

Demo: https://static.januschka.com/i-40761596/index.html

Chromium tracking issue: https://issues.chromium.org/issues/40761596

[zcorpan]

I think this could cause some web compat issues if done without opt-in. It would also introduce inconsistency with how radio buttons behave in OSes I believe.

Forms with questions that are optional could have a third radio button for "no answer" that is checked by default.