Deex

Deex is a state management library for Flutter, based on GetX but focused exclusively on state management. This README provides an overview of how to use Deex in a Flutter application.

Installation

Add Deex to your pubspec.yaml file:

dependencies:
  deex: # latest

Then run:

flutter pub get

Usage

import 'package:deex/deex.dart';

Rebuilding Widgets

The Deex widget makes the UI reactive to changes in the controller state, rebuilding the UI whenever the observed state changes.

Deex(
  () => Text('${controller.count.value}'),
),

The widget rebuilds itself every time the action is executed:

onPressed: controller.increment,

Controller

The Controller extends DeexStore and contains the reactive state, using the .obs extension to make the variables observable.

class Controller extends DeexStore {
  var count = 0.obs;
  void increment() => count++;
}

Similar to Deex, but manages a local state.

Pass the initial data in constructor. Useful for simple local states, like toggles, visibility, themes, button states, etc.

Sample:

DeexValue((data) => Switch(
    value: data.value,
    onChanged: (flag) => data.value = flag,
  ),
  false.obs,
),

Rebuilding Widgets with State

In this example, the Deex widget rebuilds the button each time the state changes. The button text is based on the current state of the RequestController.

Deex(() {
  return ElevatedButton(
    onPressed: stateController.sendRequest,
    child: Text(
      stateController.state.value.message,
    ),
  );
}),

Controller

The RequestController manages the state of the request. It sets the initial state, changes the state to "loading" when sending a request, and after a simulated delay, changes the state to "completed" with the data received.

class RequestController extends DeexStore {
  final Rx<RequestState> state = Rx<RequestState>(InitialRequestState());

  void sendRequest() {
    _setLoadingState();
    _simulateRequest()
        .then((data) => _setCompletedState(data))
        .catchError((error) => _setErrorState(error));
  }

  void _setLoadingState() {
    state.value = LoadingRequestState();
  }

  void _setCompletedState(dynamic data) {
    state.value = CompletedRequestState(data);
  }

  void _setErrorState(dynamic error) {
    state.value = ErrorRequestState(error.toString());
  }

  Future<dynamic> _simulateRequest() {
    return Future.delayed(const Duration(seconds: 2), () {
      return {'data': 'Hello World!'};
    });
  }
}

States

States represent different phases of a request. Each state has a message that describes its status.

abstract class RequestState {
  final String message;
  RequestState(this.message);
}

class InitialRequestState extends RequestState {
  InitialRequestState() : super('Request State');
}

class LoadingRequestState extends RequestState {
  LoadingRequestState() : super('Loading...');
}

class CompletedRequestState extends RequestState {
  final dynamic data;
  CompletedRequestState(this.data) : super('Request completed');
}

class ErrorRequestState extends RequestState {
  ErrorRequestState(String message) : super('Error: $message');
}

This approach allows for efficient state management, ensuring that the user interface always reflects the most recent state of the application.

License

This project is licensed under the MIT license - see the LICENSE file for more details.

Contribution

Contributions are welcome! Please open an issue or submit a pull request.

Author

Maintained by Raphael Pontes.

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Deex

Installation

Usage

Rebuilding Widgets

Widget

Controller

Similar to Deex, but manages a local state.

Rebuilding Widgets with State

Widget

Controller

States

License

Contribution

Author

Libraries

deex package