Using Dash Events to trigger callback function

I’d like to use a Dash event to trigger a callback function without passing the values. However, I’ve been trying to do this with a DateRangePicker and have been unsuccessful thus far.

Output(‘dashboard-widgets’, ‘children’),
events=[Event(’{}-dropdown’.format(name), ‘value’),
Event(’{}-date-picker’.format(name), ‘start_date’),
Event(’{}-date-picker’.format(name), ‘end_date’),)
def signal_widgets(*args):
return ‘Signaling all widgets to update’

How would one go about accomplishing this?