Flutter-Firestore Bloc

Question

我想知道如何为 Firestore 实现 Bloc 模式。
当从 flutter 默认应用程序应用 Bloc 增量应用程序时，看起来像这样。

class IncrementBloc implements BlocBase {

  int _counter;


  StreamController<int> _counterController = StreamController<int>();
  StreamSink<int> get _inAdd => _counterController.sink;
  Stream<int> get outCounter => _counterController.stream;


  StreamController<int> _actionController = StreamController<int>();
  StreamSink<int> get incrementCounter => _actionController.sink;

  IncrementBloc() {
    _counter = 0;
    _actionController.stream.listen(_handleLogic);
  }

  void _handleLogic(data) {
    _counter += 1;
    _inAdd.add(_counter);
  }

  @override
  void dispose() {
    _counterController.close();
    _actionController.close();
  }
}

问题是如何为 Firestore 实现这个逻辑。例如，如果我想在用户获得新关注者时更新徽章值，我必须监听 Firestore 文档的新创建。但我不知道如何创建涵盖这些内容的 Bloc Firestore 版本，我找不到它。我如何在 Bloc 中收听谁能告诉我如何创建它？

Answer 1

像下面这样的东西应该适合你，只需在你想要显示该值的页面上添加监听器

class IncrementBloc implements BlocBase {

  int _counter;

  StreamController<int> _counterController = StreamController<int>();
  StreamSink<int> get _inAdd => _counterController.sink;
  Stream<int> get outCounter => _counterController.stream;


  StreamController<int> _actionController = StreamController<int>();
  StreamSink<int> get incrementCounter => _actionController.sink;

  IncrementBloc() {
    // Get the latest value from firebase and listen to stream
    countAPI.getNumber().then(number) {
      _counter = number;
      _inAdd(_counter);
    });
    _actionController.stream.listen(_handleLogic);
  }

  void _handleLogic(data) async {
    _counter += 1;
    await countAPI.updateNumber(_counter); // this updates firebase
  }

  @override
  void dispose() {
    _counterController.close();
    _actionController.close();
  }
}

class APIs {
  Future<int> getNumber() async {
    try {
      // Get number from firebase
    } catch (e) {
      // Error
    }
  }

  Future<void> updateNumber() async {
    // Firebase upload 
  }
}

APIs countAPI = APIs();