onbeforeunload property
OnBeforeUnloadEventHandlerNonNull?
onbeforeunload
Implementation
OnBeforeUnloadEventHandlerNonNull? get onbeforeunload =>
js_util.getProperty(this, 'onbeforeunload');
Implementation
set onbeforeunload(OnBeforeUnloadEventHandlerNonNull? newValue) {
js_util.setProperty(this, 'onbeforeunload', newValue);
}