subscribe method

@override dynamic subscribe(String key, void callback(dynamic), { String? sourceId, })

Subscribe to a system pulse/action Returns a subscription object that implies a cancel() method or similar.

Implementation

@override
dynamic subscribe(
  String key,
  void Function(dynamic) callback, {
  String? sourceId,
}) {
  String? effectiveSourceId = sourceId;

  // Fallback: If sourceId is missing, try to infer it from the key (e.g. 'counter.increment')
  // This allows internal module state controllers (like CounterState) to subscribe
  // to their own signals even if the identity isn't explicitly passed down yet.
  if (effectiveSourceId == null && key.contains('.')) {
    effectiveSourceId = key.split('.').first;
  }

  // Record data interaction for auditing
  if (effectiveSourceId != null) {
    // Try to find the owner module from the key (e.g., 'counter.count' -> 'counter')
    final dotIndex = key.indexOf('.');
    final targetModuleId = dotIndex != -1
        ? key.substring(0, dotIndex)
        : 'unknown';

    // Only record if it's an interaction between different modules
    if (effectiveSourceId != targetModuleId) {
      recordInteraction(effectiveSourceId, targetModuleId, 'data', key);
    }
  }

  // Return the subscription via EventBus
  return EventBus().onSignal(
    key,
    callback,
    subscriberModuleId: effectiveSourceId,
  );
}