GetX Listener and Consumer Library #

This library extends the functionality of the GetX package in Flutter, allowing for efficient state management with GetListener and GetConsumer. These widgets make it easy to reactively update the UI based on changes in state.

Features #

• GetListener: A widget that listens to a specific controller or variable and rebuilds whenever the observed state changes.

• GetConsumer: A widget that allows you to consume and react to changes in a specified controller, making it easier to manage dependencies and state updates.

• Contribution This implementation was inspired by Jean Roldan, who provided valuable insights and code suggestions on Stack Overflow. Their contributions helped streamline the integration of reactive programming principles in Flutter applications.

Getting Started #

Installation #

Add the following dependency to your pubspec.yaml file:

dependencies:
  get: ^4.0.0  # or the latest version
## Usage

### GetListener

`GetListener` is useful when you need to react to changes in a specific variable from a controller without needing to rebuild the entire widget tree.

```dart
import 'package:get/get.dart';
import 'package:getx_exten/state_manager/state_manager.dart';

class MyController extends GetxController {

  final StateManager<String> stateManager = StateManager<String>();
  var counter = 0.obs;


  @override
  void onInit() {
    super.onInit();
    fetchData();

  }

  void increment(){
    counter++;

    //update();
  }

  void decrement(){
    counter--;
  }



  Future<void> fetchData() async {
    stateManager.setLoading();
    await Future.delayed(Duration(seconds: 2)).then((_){
      stateManager.setSuccess("Fetched Data");
    });

  }

  Future<void> fetchDataWithError() async {
    stateManager.setLoading();
    await Future.delayed(Duration(seconds: 2));
    stateManager.setError("Error occurred");
  }

}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: GetListener(
          stateManager: controller.stateManager,
          listener: (context, state) {
            if (controller.stateManager.status.value == RxState.error) {
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(content: Text("Error: ${controller.stateManager.status}")),
              );
            }else if(controller.stateManager.status.value == RxState.success){
              print('hi');
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(content: Text("Success: ${controller.stateManager.data}")),
              );
            }
          },
          child: GetConsumer<String>(
            stateManager: controller.stateManager,
            listener: (context, state) {
              // if (controller.stateManager.status.value == RxState.error) {
              //   ScaffoldMessenger.of(context).showSnackBar(
              //     SnackBar(content: Text("Error: ${controller.stateManager.status}")),
              //   );
              // }else if(controller.stateManager.status.value == RxState.success){
              //   print('hi');
              //   ScaffoldMessenger.of(context).showSnackBar(
              //     SnackBar(content: Text("Success: ${controller.stateManager.status}")),
              //   );
              //}
            },
            onLoading: const Center(child: CircularProgressIndicator()),
            successWidget: (data) => Center(child: Text(data ?? "Success")),
            onError: (error) => Center(child: Text("Error: $error")),
            onEmpty: const Center(child: Text("No data available")),

          ),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: controller.increment,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

License
This project is licensed under the MIT License. See the LICENSE file for more details.