bsev 0.1.0

Useful to aid in the use of BloC pattern with dependency injection

BSEV (BloC,Streams,Events,View)

Useful to aid in the use of BloC pattern with dependency injection

Usage

To use this plugin, add bsev as a dependency in your pubspec.yaml file.

We should initially create the class that represents our Streams and Events:

Streams

import 'package:bsev/bsev.dart';

class HomeStreams extends StreamsBase{

  var count = BehaviorSubjectCreate<Int>(initValue: 0);
  //var count = StreamCreate<Int>();
  //var count = PublishSubjectCreate<Int>();
  //var count = ReplaySubjectCreate<Int>();

  @override
  void dispose() {
    count.close();
  }

}

Events

import 'package:bsev/bsev.dart';

class HomeEvents extends EventsBase{}

class IncrementEvent extends HomeEvents{}

Now we can create our Bloc, class that will be centralized the business rule.

Bloc

import 'package:bsev/bsev.dart';

class HomeBloc extends BlocBase<HomeStreams,HomeEvents>{

  @override
  void initView() {
    //If you need to get a Bloc from the top widget hierarchy you can use:
    //ATTENTION: Do not call this method (getBloc) in the block constructor. Only in the initView or after the initView is called at least once.
    //var otherBloc = getBloc<Bloc>();
    //otherBloc.dispatch(Event());

  }
  
  @override
  void eventReceiver(EventsBase event) {
    if(event is IncrementEvent){
      streams.count.set(streams.count.value + 1)
    }
  }
}

In our bloc we have 2 mandatory methods: initState and eventReceiver:

initView: In the first buildView this method is invoked;

eventReceiver: Invoked whenever the pad receives an event;

View

import 'package:bsev/bsev.dart';

class HomeView extends BlocStatelessView<HomeBloc,HomeStreams> {

   @override
  void eventReceiver(HomeEvents event) {
    // performs action received by the bloc
  }
  
  @override
  Widget buildView(BuildContext context) {
  
    //If you need to get a Bloc from the top widget hierarchy you can use:
    //var otherBloc = getBloc<Bloc>(context);
    //otherBloc.dispatch(Event());

    return Scaffold(
      key: scaffoldStateKey,
      appBar: AppBar(),
      body: _buildBody(),
      floatingActionButton: FloatingActionButton(
          onPressed: (){
            dispatch(IncrementEvent());
          }
      ),
    );
    
    Widget _buildBody() {
    
      return StreamBuilder(
        stream: streams.count.get,
        initialData: 0,
        builder: (_,snapshot){
          
          int count = 0;
          if(snapshot.hasData){
            count = snapshot.data;
          }
          
          return Center(
            child: Text(count)
          )
        }
      );
      
    }
  
}

As our Bloc and our StreamsBase will be injected automatically, we should configure it in the Injector in the main of our application:

  MyApp(){

    var injector = Injector.appInstance;
    injector.registerDependency((i)=> HomeBloc());
    injector.registerDependency((i)=> HomeStreams());
    
  }

Finally we instantiate our HomeView running:

HomeView().create()

More complex example is found here: exemplo

Used packages

rxdart: ^0.21.0

injector: ^1.0.8

provider: ^2.0.1