Class MessageRelay<TMessage>

Namespace: mobisim.Core.EventFramework

Bridge between the event-aggregator bus and Unity's inspector-wired event system, allowing TMessage arrivals to drive any UnityEvent target without writing code.

public abstract class MessageRelay<TMessage> : MonoBehaviour, IHandle<TMessage> where TMessage : IMessage

Type Parameters

Name	Type	Description
TMessage		The type of message to subscribe to and relay.

Inheritance

object→Object→Component→Behaviour→MonoBehaviour→MessageRelay<TMessage>

Implements

IHandle<TMessage>

Examples

// A concrete relay that bridges BatteryMessage to a UnityEvent wired in the Inspector:
public class BatteryMessageRelay : MessageRelay
{
    [SerializeField] private UnityEvent OnBatteryLevelChanged;
    public override void Handle(BatteryMessage msg) => OnBatteryLevelChanged?.Invoke(msg.level);
}

Remarks

Unity's built-in components (sliders, text labels, animators, …) expose UnityEvents that can be wired in the Inspector, but they cannot directly implement IHandle. MessageRelay fills the gap: a small adapter MonoBehaviour that subscribes to the aggregator, receives the typed message, and fires a UnityEvent that the built-in component's callback can be connected to via drag-and-drop in the Inspector.

Subclasses are abstract because the mapping from TMessage fields to UnityEvent arguments is message-specific. A BatteryMessageRelay, for example, would extract msg.level and pass it to a UnityEvent. This design keeps the base class completely generic while letting each concrete relay own its own UnityEvent declaration and Inspector layout.

Fields

m_ChannelKey

Channel this relay listens on; null subscribes to the global default channel.

[SerializeField]
protected ChannelKey m_ChannelKey

Field Value

ChannelKey

Remarks

Must match the channel used by the publisher. In multi-vehicle scenes, assign each relay to its vehicle's own ChannelKey asset so relays only respond to messages from the vehicle they are attached to.

Methods

Handle(TMessage)

Receives the TMessage from the aggregator and converts it into the appropriate UnityEvent invocation.

public abstract void Handle(TMessage message)

Parameters

Name	Type	Description
message	TMessage	The message payload delivered by the aggregator.

Remarks

Subclasses extract the relevant fields from message and pass them to their declared UnityEvent. For example, a battery relay would call OnBatteryLevelChanged?.Invoke(msg.level).

OnDisable()

Unsubscribes from the IEventAggregator when this relay is deactivated.

protected virtual void OnDisable()

OnEnable()

Subscribes to the IEventAggregator when this relay becomes active.

protected virtual void OnEnable()

Remarks

virtual so subclasses can subscribe to additional channels or perform extra setup before or after calling base.OnEnable().