NodeFlowExtension<T> class abstract interface

Interface for extensions that can observe and react to graph events.

Extensions are purely additive - they observe events and provide additional capabilities without modifying core behavior.

Lifecycle

1. Extension is created
2. attach is called with the controller reference
3. onEvent is called for each graph event
4. detach is called when the extension is removed

Example Implementation

class LoggingExtension<T> implements NodeFlowExtension<T> {
  NodeFlowController<T>? _controller;

  @override
  String get id => 'logging';

  @override
  void attach(NodeFlowController<T> controller) {
    _controller = controller;
    print('Logging extension attached');
  }

  @override
  void detach() {
    _controller = null;
    print('Logging extension detached');
  }

  @override
  void onEvent(GraphEvent event) {
    print('Event: $event');
  }
}

Usage

final controller = NodeFlowController<MyData>();
controller.addExtension(LoggingExtension<MyData>());