Flutter - Dependency Injection - flutter

Question

I am after some best practise tips for developing my Flutter app.
Currently, I have an app with multiple pages and multiple plugins such as network connection, SQLite, Location etc.
Currently, on each page, I am creating a new instance of each plugin I need access to as shown below, and then using the plugin functionality.
final _secureStorage = FlutterSecureStorage();
final FirebaseMessaging _firebaseMessaging = FirebaseMessaging();
What I want to achieve: I would like to possibly only create an instance of these classes once, and then be able to access the instance in all pages - something like Dependency Injection.
Currently, I am looking into InheritedWidget widget or the Provider package, however, I am not sure if they do what I am trying to achieve as I don't want to inherit or pass around widgets, I want to inject classes instances.

Answer 1

You could try out, the get_it package, since it is not tied to Flutter.
https://pub.dev/packages/get_it

Answer 2

The ioc_container may suit your case because it has specific documentation on how to use it with Firebase and firebase Messaging. It does exactly as you say: initialize Firebase asynchronously and store the instances as singletons with dependency injection.
Here is a snippet of the code from the documentation:
extension FlutterFireExtensions on IocContainerBuilder {
void addFirebase() {
//These factories are all async because we need to ensure that Firebase is initialized
addSingletonAsync(
(container) {
WidgetsFlutterBinding.ensureInitialized();
return Firebase.initializeApp(
options: container.get<FirebaseOptions>(),
);
},
);
addSingletonAsync(
(container) async => FirebaseAuth.instanceFor(
app: await container.getAsync<FirebaseApp>(),
),
);
addSingletonAsync(
(container) async => FirebaseFirestore.instanceFor(
app: await container.getAsync<FirebaseApp>(),
),
);
addSingletonAsync((container) async {
//Ensure we have already initialized Firebase
await container.getAsync<FirebaseApp>();
return FirebaseMessaging.instance;
});
}
}