Avoid Public Bloc Methods

newdartrecommended

Avoid exposing public methods on Bloc instances.

Rationale

Blocs react to incoming events and emit outgoing states. As a result, the recommended way of communicating with a bloc instance is via the add method. In most cases, there’s no need to create additional abstractions on top of the add API.

Examples

DO NOT expose public methods on bloc instances.

BAD:

counter_bloc.dart

import 'package:bloc/bloc.dart';

enum CounterEvent { increment };

class CounterBloc extends Bloc<CounterEvent, int> {
  CounterBloc() : super(0) {
    on<CounterEvent>((event, emit) => emit(state + 1));
  }

  // Avoid public bloc methods!
  // Prefer to use [add] directly.
  void increment() => add(CounterEvent.increment);
}

GOOD:

counter_bloc.dart

import 'package:bloc/bloc.dart';

enum CounterEvent { increment };

class CounterBloc extends Bloc<CounterEvent, int> {
  CounterBloc() : super(0) {
    on<CounterEvent>((event, emit) => emit(state + 1));
  }
}

Enable

To enable the avoid_public_bloc_methods rule, add it to your analysis_options.yaml under bloc > rules:

YAML List

analysis_options.yaml

bloc:
  rules:
    - avoid_public_bloc_methods

YAML Map

analysis_options.yaml

bloc:
  rules:
    avoid_public_bloc_methods: true