Flutter multi module dependency injection

An easy-to-use DI that works based on a dependency tree.

Installation

In the dependencies: section of your pubspec.yaml, add the following line:

Important note:

From 2.0.0 and onwards, flutter_multi_module_di uses null-safe code.

dependencies:
    flutter_multi_module_di: latest_version

Multi module example

You can use a dependency tree for the entire application, widget and component.

Usage

class MainPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChildInjectorStatefulWidget(
      childModuleBuilder: () => MainModule(context),
      injectorBuilder: (i) => _MainWidget(i.get(), i.get(name: "test_1")),
    );
  }
}

class _MainWidget extends StatelessWidget {
  final MainBloc _bloc;
  final String _testSrt;

  _MainWidget(this._bloc, this._testSrt);

  @override
  Widget build(BuildContext context) {
   ...
  }
}

You can also extend WidgetModule to configure your dependencies:

class MainModule extends WidgetModule {
  MainModule(BuildContext context) : super(context);

  @override
  void configureWidget(Binder binder) {
    binder..bindLazySingleton((i, _) => MainBloc(i.get(), i.get())..add(MainPageOpenedEvent()));

    binder..bindLazySingleton((i, _) => MainNavigator(i.get()));
  }
}

or use common dart module

class TestModule extends Module {
  @override
  void configure(Binder binder) {
    // impl
  }
}

You can later refer to the injector like any other InheritedWidget.

class SomeWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final injector = InjectorWidget.of(context);
    final apiKey = injector.get(name: "api_key");
    return SomeContainerNeedingTheKey(apiKey);
  }
}

Or using the InjectorWidgetMixin:

class SomeWidget extends StatelessWidget with InjectorWidgetMixin {
  @override
  Widget buildWithInjector(BuildContext context, Injector injector) {
    final object = injector.get<Object>();
    print(object);
    return Container();
  }
}

Full api

ChildInjectorStatefulWidget

Creates a singleton module containing the child module and parent dependencies

class MainPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChildInjectorStatefulWidget(
      childModuleBuilder: () => MainModule(context),
      injectorBuilder: (i) => _MainWidget(i.get(), i.get(name: "test_1")),
    );
  }
}

ChildInjectorWidget

Creates a new module containing the child module and parent dependencies

class MainPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChildInjectorWidget(
      childModule: MainModule(context),
      injectorBuilder: (injector) {
       ...
      },
    );
  }
}

InjectorWidget

@override
Widget build(BuildContext context) {
  return InjectorWidget(
    child: Text(""),
    injector: Injector.fromModule(module: ...),
    autoDispose: true, // default: true
  );
}

InjectorWidgetMixin

class TestWidget with InjectorWidgetMixin {
  @override
  Widget buildWithInjector(BuildContext context, Injector injector) {
    injector.get(name: "test_key");
    return Container();
  }
}

WithInjectorWidget & WithInstanceWidget

@override
Widget build(BuildContext context) {
  return WithInjectorWidget(
    builder: (injector) {
      injector.get(name: "test");
      return Container();
    },
  );
}

@override
Widget build(BuildContext context) {
  return WithInstanceWidget<SharedPreferences>(
    builder: (sharedPrefs) {
      return Container();
    },
  );
}

ModuleWidget

class TestWidget extends ModuleWidget {
  @override
  void configure(Binder binder) {
    
  }
}