flutter_ioc_container 0.4.0

A Flutter extension for the ioc_container package

flutter_ioc_container

Flutter extensions that allow you to use the ioc_container throughout the widget tree. The library provides extension methods on BuildContext to allow getting instances of objects from the container, such as get<T>(), getAsync<T>(), and scoped<T>().

Getting Started

Installing the Package

To use "flutter_ioc_container", add the following line to your pubspec.yaml file under the dependencies section:

flutter_ioc_container: <latest version>

Run flutter pub get to download the dependencies.

Defining and Injecting Dependencies

You can define your dependencies and inject them into your widgets using the CompositionRoot widget. You can either pass an IocContainer instance into container or use the compose property to define your dependencies. The CompositionRoot widget houses the IoC container and is placed at the root of the widget tree to propagate it throughout the widgets.

Basic Injection

Let's say you want to inject a string into your widget tree. To do this, you can define a string and pass it to the CompositionRoot widget as a parameter. Here's an example:

const text = 'test';
final root = CompositionRoot(
    compose: (builder) => builder.add((container) => text),
    child: const BasicWidget(),
);

Scoped Injection

If you need a set of dependencies that have a short life and you want to dispose of them afterwards, you can use the scoped method to create a scoped container. Here's an example:

final root = CompositionRoot(
    container: (IocContainerBuilder()
        ..add(
            (container) => A(),
        )
        ..add(
            (container) => B(),
        )
        ..add(
            (container) => C(
            container<B>(),
            container<B>(),
            ),
        ))
        .toContainer(),
    child: const BasicWidgetWithScope(),
);

You can load the dependencies in the State of your widget

@override
void didChangeDependencies() {
final scope = context.scoped();
one = scope<A>();
two = scope<A>();
c = context.getScoped<C>();
super.didChangeDependencies();
}

Async Injection

If you want to inject an object into the widget tree that is loaded asynchronously, you can do so using 'addAsync'. You can use the FutureBuilder widget to render the object when it is available. Here's an example:

const text = 'test';
final root = CompositionRoot(
    compose: (builder) => builder.addAsync(
    (container) async =>
        Future<String>.delayed(const Duration(seconds: 1), () => text),
    ),
    child: const BasicAsyncWidget(),
);

You can access the future with FutureBuilder like this.

class _BasicAsyncWidgetState extends State<BasicAsyncWidget> {
  late final Future<String> future;

  @override
  void didChangeDependencies() {
    // ignore: discarded_futures
    future = context.getAsync<String>();
    super.didChangeDependencies();
  }

  @override
  Widget build(BuildContext context) => MaterialApp(
        home: FutureBuilder(
          // ignore: discarded_futures
          future: future,
          builder: (ctx, ss) => ss.connectionState == ConnectionState.done
              ? Text(ss.data!)
              : const CircularProgressIndicator(),
        ),
      );
}