Mastering Python for Finance - Second Edition

Storing the order event handler

Add the following two methods as the getter and setter for the order event handler, respectively:

@property
def on_order_event(self):
    """
    Listeners will receive: transaction_id
    """
    return self.__order_event_handler

@on_order_event.setter
def on_order_event(self, event_handler):
    self.__order_event_handler = event_handler

After an order is routed to your broker, the inheriting child classes will notify the listeners through the on_order_event method invocation, along with the order transaction ID.