Dependency Injection in GetX

GetX features a powerful dependency injection manager that operates independently of the Flutter widget tree. This allows you to register and locate services and controllers context-lessly from any file in your project.

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1. Exposing Dependencies

GetX provides several methods to inject your controllers, models, or services into memory:

Get.put()

Instantiates the class synchronously and caches it in memory immediately. Ideal for controllers that are always needed when a screen loads.

final controller = Get.put(CounterController());

Get.lazyPut()

Caches the builder function of the class. The class is only instantiated when it is retrieved for the first time via Get.find(). Ideal for memory optimization.

Get.lazyPut(() => BigDataService());

Get.putAsync()

Used for asynchronous initializations (e.g. configuring a local database or loading shared preferences).

await Get.putAsync<SharedPreferences>(() async {
  return await SharedPreferences.getInstance();
});

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2. Retrieving Dependencies with Get.find()

Once a dependency has been registered, you can find it anywhere in your application using Get.find():

class AnotherScreen extends StatelessWidget {
  const AnotherScreen({super.key});

  @override
  Widget build(BuildContext context) {
    // 1. Locate the already running counter controller
    final CounterController controller = Get.find();

    return Scaffold(
      body: Center(
        child: ElevatedButton(
          onPressed: controller.increment,
          child: const Text('Increment from Another Screen'),
        ),
      ),
    );
  }
}

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3. Difference Summary

Method	Instantiation Time	Keeps in Memory	Good for
Get.put	Immediate (Synchronous)	Always (unless manually deleted)	Primary page controllers
Get.lazyPut	On First Use (Lazy)	Cleared when route closes	Resource-heavy classes
Get.putAsync	Asynchronous	Always	Services (DB initialization, API client setups)