[dart:async]Controller.broadcast Basic Usage

main.dart

import 'dart:async';

main() {
  StreamTransformer transformer = StreamTransformer<num, num>.fromHandlers(
    handleData: (num val, EventSink sink) {
      sink.add(-val);
    }
  );
  StreamController controller = StreamController<num>.broadcast(
    onListen: () {
      print('New subscriber connected.');
    },
  );
  Stream transformed = controller.stream.transform(transformer);
  
  controller.stream.listen((val) {
    print('[Original] Event received: $val');
  }, onDone: () {
    print('[Original] Stream done');
  });
  
  transformed.listen((val) {
    print('\t[Transformed] Event received: $val');
  }, onDone: () {
    print('\t[Transformed] Stream done');
  });
  
  for (var i = 0; i < 10; i++) {
  	controller.sink.add(i);
  }
  
  controller.close();
}