how can I get the other controller's variable inside one controller in flutter using getx

Issue

This is an issue related to the getx in flutter.
I have 2 controllers. ContractsController and NotificationController.
In ContractsController I have put the value into observer variable by calling the Api request.
What I want now is to get that variable’s data in another controller – NotificationController.
How to get that value using getx functions?

ContractsController

class ContractsController extends GetxController {
  ExpiringContractRepository _expiringContractRepository;

  final expiringContracts = <ExpiringContract>[].obs; // This is the value what I want in another controller

  ContractsController() {
    _expiringContractRepository = new ExpiringContractRepository();
  }

  @override
  Future<void> onInit() async {
    await refreshContracts();
    super.onInit();
  }

  Future refreshContracts({bool showMessage}) async {
    await getExpiringContracts();
    if (showMessage == true) {
      Get.showSnackbar(Ui.SuccessSnackBar(message: "List of expiring contracts refreshed successfully".tr));
    }
  }

  Future getExpiringContracts() async {
    try {
      expiringContracts.value = await _expiringContractRepository.getAll(); // put the value from the api
    } catch (e) {
      Get.showSnackbar(Ui.ErrorSnackBar(message: e.toString()));
    }
  }
}

The expiringContracts is updated successfully with data after the api request.
Now, I want to get that value in NotificationController

NotificationController

class NotificationsController extends GetxController {
  final notifications = <Notification>[].obs;
  ContractsController contractsController;

  NotificationsController() {
  }

  @override
  void onInit() async {
    contractsController = Get.find<ContractsController>();
    print(contractsController.expiringContracts);  // This shows an empty list ?????  
    super.onInit();
  }

}

Solution

There were some powerful approaches in GetX. I solved this issue with Get.put and Get.find

Here is the code that I added.

ContractsController

class ContractsController extends GetxController {
  ExpiringContractRepository _expiringContractRepository;

  final expiringContracts = <ExpiringContract>[].obs; // This is the value what I want in another controller

  ContractsController() {
    _expiringContractRepository = new ExpiringContractRepository();
  }

  @override
  Future<void> onInit() async {
    await refreshContracts();
    super.onInit();
  }

  Future refreshContracts({bool showMessage}) async {
    await getExpiringContracts();
    if (showMessage == true) {
      Get.showSnackbar(Ui.SuccessSnackBar(message: "List of expiring contracts refreshed successfully".tr));
    }
  }

  Future getExpiringContracts() async {
    try {
      expiringContracts.value = await _expiringContractRepository.getAll(); // put the value from the API
      // ******************************** //
      Get.put(ContractsController()); // Added here
    } catch (e) {
      Get.showSnackbar(Ui.ErrorSnackBar(message: e.toString()));
    }
  }
}

NotificationController

class NotificationsController extends GetxController {
  final notifications = <Notification>[].obs;
  ContractsController contractsController;

  NotificationsController() {
  }

  @override
  void onInit() async {
    // ******************************** //
    contractsController = Get.find<ContractsController>(); // Added here.
    print(contractsController.expiringContracts);  // This shows the updated value
    super.onInit();
  }
}

Finally, I have found that GetX is simple but powerful for state management in flutter.
Thanks.

Answered By – Speeder

Answer Checked By – Clifford M. (FlutterFixes Volunteer)