home_bloc.dart

import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:rnm_graphql/blocs/home/home.dart';
import 'package:rnm_graphql/services/graphql_service.dart';

class HomeBloc extends Bloc<HomeEvents, HomeStates> {
  GraphQLService service;

  HomeBloc() {
    service = GraphQLService();
  }

  @override
  HomeStates get initialState => Loading();

  @override
  Stream<HomeStates> mapEventToState(HomeEvents event) async* {
    if (event is FetchHomeData) {
      yield* _mapFetchHomeDataToStates(event);
    }
  }

  Stream<HomeStates> _mapFetchHomeDataToStates(FetchHomeData event) async* {
    final query = event.query;
    final variables = event.variables ?? null;

    try {
      final result = await service.performMutation(query, variables: variables);

      if (result.hasException) {
        print('graphQLErrors: ${result.exception.graphqlErrors.toString()}');
        print('clientErrors: ${result.exception.clientException.toString()}');
        yield LoadDataFail(result.exception.graphqlErrors[0]);
      } else {
        yield LoadDataSuccess(result.data);
      }
    } catch (e) {
      print(e);
      yield LoadDataFail(e.toString());
    }
  }
}

home_bucket.dart

export './home_bloc.dart';
export './home_events.dart';
export './home_states.dart';

home_events.dart

import 'package:equatable/equatable.dart';

abstract class HomeEvents extends Equatable {
  HomeEvents();

  @override
  List<Object> get props => null;
}

class FetchHomeData extends HomeEvents {
  final String query;
  final Map<String, dynamic> variables;

  FetchHomeData(this.query, {this.variables}) : super();

  @override
  List<Object> get props => [query, variables];
}

home_states.dart

import 'package:equatable/equatable.dart';

abstract class HomeStates extends Equatable {
  HomeStates();

  @override
  List<Object> get props => null;
}

class Loading extends HomeStates {
  Loading() : super();
}

class LoadDataSuccess extends HomeStates {
  final dynamic data;

  LoadDataSuccess(this.data) : super();

  @override
  List<Object> get props => data;
}

class LoadDataFail extends HomeStates {
  final dynamic error;

  LoadDataFail(this.error) : super();

  @override
  List<Object> get props => error;
}