The oncancel property of the GlobalEventHandlers mixin is an event handler for processing cancel events sent to a <dialog> element.

The cancel event fires when the user indicates a wish to dismiss a <dialog>. This event handler prevents the event from bubbling, so any parent handlers are not notified of the event.

functionRef is a function name or a function expression. The function receives an Event object as its sole argument.

Only one oncancel handler can be assigned to an object at a time. You may prefer to use the EventTarget.addEventListener() method instead, since it's more flexible.

• cancel event
• HTML <dialog> element
• Related event handler: GlobalEventHandlers.onclose