Eagle Provider
A simple state management package that uses only ValueNotifier and InheritedWidget.
Usage
To use it, just create a state class and another to be the state controller.
To create a state class follow the example below:
OBS: State class must always extend from StateController.
// State
class HomeState extends StateController {
HomeState({this.title, super.status});
final String? title;
@override
copyWith({
Status? status,
String? title,
}) {
return HomeState(
status: status ?? this.status,
title: title ?? this.title,
);
}
@override
List<Object?> get props => [status, title];
}
And to create the controller is simple. The controller must extend from Controller of type StateController:
// Controller
class HomeController extends Controller<HomeState> {
HomeController() : super(HomeState());
changeStatus() {
emit(state.copyWith(status: Status.success));
}
}
To inject the dependencies use the ControllerProvider at the top of the widget tree.
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return ControllerProvider(
controllers: [
HomeController(),
],
child: MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(),
),
);
}
}
Usage of the ControllerBuilder
The ControllerBuilder is a widget that allows you to build your user interface in a reactive way to the states controlled by your application.
You can use the ControllerBuilder by passing your controller as a parameter or, if it is not passed, the widget will search for it in the widget tree using the ControllerProvider.
The widget also calls the builder whenever the buildWhen condition is met and returns the output of the builder as its child. If the buildWhen condition is not met, it returns the last output of the builder.
To update your interface according to state changes, use the following widget:
class MyHomePage extends StatelessWidget {
const MyHomePage({super.key});
@override
Widget build(BuildContext context) {
var controller = HomeController();
Future.delayed(const Duration(seconds: 3)).then(
(value) {
controller.changeStatus();
},
);
return Scaffold(
appBar: AppBar(
title: const Text('Home page'),
),
body: ControllerBuilder<HomeController, HomeState>(
buildWhen: (before, after) {
return before.status != after.status;
},
builder: (BuildContext context, state) {
if (state.status == Status.loading) {
return const Center(child: CircularProgressIndicator());
}
return const Center(
child: Text('Home completed loading'),
);
},
),
);
}
}
Example
For more questions, run the sample project.