IOrderExecutionListener

IOrderExecutionListener defines the interface for components that react to order lifecycle events. It is used by OrderExecutionBus to notify subscribers of changes in order state.

class IOrderExecutionListener : public ISubscriber {
public:
  explicit IOrderExecutionListener(SubscriberId id);
  virtual ~IOrderExecutionListener() = default;

  SubscriberId id() const override;

  virtual void onOrderSubmitted(const Order& order) = 0;
  virtual void onOrderAccepted(const Order& order) = 0;
  virtual void onOrderPartiallyFilled(const Order& order, Quantity fillQty) = 0;
  virtual void onOrderFilled(const Order& order) = 0;
  virtual void onOrderCanceled(const Order& order) = 0;
  virtual void onOrderExpired(const Order& order) = 0;
  virtual void onOrderRejected(const Order& order, const std::string& reason) = 0;
  virtual void onOrderReplaced(const Order& oldOrder, const Order& newOrder) = 0;
};

Purpose

• Provide a type-safe listener interface for receiving detailed updates on order status transitions.

Responsibilities

Method	Triggered On
onOrderSubmitted	Order submitted to venue or simulator.
onOrderAccepted	Order acknowledged/accepted by the exchange.
onOrderPartiallyFilled	Partial fill received; includes fill quantity.
onOrderFilled	Fully filled.
onOrderCanceled	Canceled by user or system.
onOrderExpired	Expired due to time-in-force or system conditions.
onOrderRejected	Rejected by exchange or risk engine (with reason).
onOrderReplaced	Order was replaced with a new one.

Notes

• Each listener is identified via a stable SubscriberId.
• Used in tandem with OrderEvent::dispatchTo() to decouple producers from listeners.
• Implemented by components such as PositionManager, ExecutionTracker, and metrics/reporting modules.