BlocProvider

bloc.dart

import 'package:flutter/material.dart';
import 'package:rxdart/rxdart.dart';

abstract class BlocBase {
  void dispose();
}

class BlocProvider<T extends BlocBase> extends StatefulWidget {
  const BlocProvider({
    super.key,
    required this.bloc,
    required this.child,
  });

  final T bloc;
  final Widget child;

  @override
  BlocProviderState<T> createState() => _BlocProviderState<T>();

  static T of<T extends BlocBase>(BuildContext context){
    final provider = context.findAncestorWidgetOfExactType() as BlocProvider<T>?;
    if (provider == null) {
      throw 'Widget not found in BlocProvider tree';
    }
    return provider.bloc;
  }
}

class BlocProviderState<T> extends State<BlocProvider<BlocBase>>{
  @override
  void dispose(){
    widget.bloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context){
    return widget.child;
  }
}

// An example bloc class to showcase how to use it
class ExampleBloc implements BlocBase {
  final _isFavorite = BehaviorSubject<bool>();
  Stream<bool> get isFavorite => _isFavorite.stream;
  
  @override
  void dispose() {
    _isFavorite.close();
  }
}

// How to create a page widget
BlocProvider<ExampleBloc>(
  bloc: ExampleBloc(),
  child: YouPage(),
);

// How to get bloc in children
final bloc = BlocProvider.of<ExampleBloc>(context);