Unconditional Delivery Listeners

The where clause argument in the addDeleteListener method is optional. When it is not provided, the real-time database will deliver any object  which is being deleted from the database's table:

Using MapCustom Class

EventHandler<Map> orderEventHandler = Backendless.data.of("Order").rt();

orderEventHandler.addDeleteListener((deletedOrder) {
  print("An Order object has been deleted. Object ID - ${deletedOrder['objectId']}");
});

EventHandler<Order> orderEventHandler = Backendless.data.withClass<Order>().rt();

orderEventHandler.addDeleteListener((deletedOrder) {
  print("An Order object has been deleted. Object ID - ${deletedOrder.objectId}");
});