How is data exchanged between isolated system components?

In Flutter, data exchange between isolated components of the system (for example, between widgets or layers of the application) is usually carried out through several approaches:

• State and state management: Using state management patterns (Provider, Bloc, Riverpod, Redux, etc.) allows passing data and events between components while maintaining their isolation.

• Callback functions: The parent widget passes a callback to the child, which is called upon state changes or events.

• Streams and events: Using StreamController and StreamBuilder to pass asynchronous data between components.

• InheritedWidget and Context: Allow passing data down the widget tree without explicitly passing them through parameters.

Example using Provider:

class Counter with ChangeNotifier {
  int _count = 0;
  int get count => _count;

  void increment() {
    _count++;
    notifyListeners();
  }
}

// In widget:
Consumer<Counter>(
  builder: (context, counter, child) => Text('Count: \\${counter.count}'),
)

Thus, data and events are passed through managed state, keeping components isolated and independent.