bloc_ui_generator 1.0.9

A Dart package for generation of typed BloC widgets like BlocBuilder and BlocListener for concrete implementations

Provides Dart Build System builders for typed BlocBuilders, BlocListeners, BlocConsumers, BlocSelectors and BlocProviders, as well as BuildContext extensions fur read, watch and select.

The builders generate code when they find members annotated with classes defined in package:bloc_ui_annotation.

• To generate UI code for a class that extends Bloc or Cubit, annotate it with GenerateBlocUI. You can provide the argument selectorClasses to GenerateBlocUI to configure which BlocSelector output types should be generated.

Setup

To configure your project, you need to add bloc_ui_annotation as a dependency to your pubspec.yaml file, as well as bloc_ui_generator as a development dependency:

dependencies:
  bloc_ui_annotation: 

dev_dependencies:
  bloc_ui_generator:

Example

Given a library example.dart with a CounterBloc class extending Bloc, annotated with GenerateBlocUI:

import 'package:bloc_ui_annotation/bloc_ui_annotation.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

part 'counter_event.dart';
part 'example.g.dart';

@GenerateBlocUI(
  selectorClasses: {'String'},
)
class CounterBloc extends Bloc<CounterEvent, int> {
  CounterBloc() : super(0) {
    on<CounterEvent>((event, emit) {
      // TODO: implement event handler
    });
  }
}

Building created the corresponding part example.g.dart:

part of 'example.dart';

// **************************************************************************
// BlocUIGenerator
// **************************************************************************

class CounterBlocBuilder extends BlocBuilder<CounterBloc, int> {
  const CounterBlocBuilder({
    super.key,
    required super.builder,
    super.buildWhen,
    super.bloc,
  });
}

class CounterBlocListener extends BlocListener<CounterBloc, int> {
  const CounterBlocListener({
    super.key,
    required super.listener,
    super.bloc,
    super.listenWhen,
    super.child,
  });
}

class CounterBlocConsumer extends BlocConsumer<CounterBloc, int> {
  const CounterBlocConsumer({
    super.key,
    required super.builder,
    required super.listener,
    super.bloc,
    super.buildWhen,
    super.listenWhen,
  });
}

class CounterBlocStringSelector
    extends BlocSelector<CounterBloc, int, String> {
  const CounterBlocStringSelector({
    super.key,
    required super.selector,
    required super.builder,
    super.bloc,
  });
}

class CounterBlocProvider extends BlocProvider<CounterBloc> {
  const CounterBlocProvider({
    required super.create,
    super.key,
    super.child,
    super.lazy = true,
  });

  const CounterBlocProvider.value({
    required super.value,
    super.key,
    super.child,
  }) : super.value();
}

extension CounterBlocContextExtension on BuildContext {
  CounterBloc get readTestBloc => read<CounterBloc>();
  CounterBloc get watchTestBloc => watch<CounterBloc>();
  R selectCounterBloc<R>(R Function(CounterBloc value) selector) =>
          select<CounterBloc, R>(selector);
}

Running the code generator

Once you have added the annotations to your code you then need to run the code generator to generate the missing .g.dart generated dart files.

Run dart run build_runner build in the package directory.

Annotation values

The only annotation required to use this package is GenerateBlocUI. When applied to a class (in a correctly configured package), typed BlocBuilder, BlocListener, BlocConsumer, BlocProvider and BuildContext extension code will be generated when you build. Additionally, you can provide a Set<String> to the selectorClasses parameter of GenerateBlocUI, to generate one or more BlocSelectors as well.

Bloc definition

Note that any Blocs or Cubits names must extend Bloc or Cubit, e.g. TestBloc extends Bloc<A, B> or TestCubit extends Cubit<A>. If an annotated class does not extend one of these classes, an error will be thrown when running code generation.

Selector generation

BlocSelectors will be generated once the selectorClasses parameter is provided with at least one value. You can add multiple Strings to the Set, each leading to the generation of another BlocSelector.

Please note that the code generation does simply use the given value without any checks or referencing the actual type. This means, that renaming classes does not automatically adapt the corresponding BlocSelector, even after re-running code generation.