Custom Conditional Placeholder has_attendees

add_action('em_event_output_condition', 'my_em_has_attendees_event_output_condition', 1, 4);
function my_em_has_attendees_event_output_condition($replacement, $condition, $match, $EM_Event){
	if( is_object($EM_Event) && preg_match('/^has_attendees/',$condition, $matches) ){
		if( $EM_Event->get_bookings()->get_booked_spaces() > 0 ){
			$replacement = preg_replace("/\{\/?$condition\}/", '', $match);
		}else{
			$replacement = '';
		}
	}
	return $replacement;
}