spread 0.0.4

spread: ^0.0.4 copied to clipboard

Spread Library #

Easily manage and observe the state of your Flutter applications.

Overview #

The Spread library offers a simplified way of managing state within Flutter applications. With the use of entities, subscribers, and state emitters, developers can easily store, observe, and manipulate states without the usual boilerplate.

Features #

• State Management: Store state data using identifiers, types, or entities. It's like a Key-Value map with observable events.
• Spread Widget: Update UI when receive a state update.
• Observers: Subscribe to specific state changes and react accordingly.
• State Emitters: a Mixin to Emit state changes based on types, names, or entities.
• Use Cases: Abstracted business or domain logic encapsulation with the UseCase class.
• Entities: Subscribe UI changes to a specific object instance identified by Type and ID.

Getting Started #

Installation

Include the library in your pubspec.yaml:

dependencies:
   spread: ^0.0.4

Then run:

pub get

Basic Usage

Define a state entity:

import 'package:spread/entity.dart';

class User implements Entity {
  final String id;
  final String name;

  User({required this.id, required this.name});

  @override
  String get entityId => id;
}

and/or Define a typed entity:

import 'user.dart';

abstract class UsersState {}

class LoadingUsers extends UsersState {}

class LoadedUsersSuccess extends UsersState {
  final List<User> users;

  LoadedUsersSuccess({required this.users});
}

class LoadedUsersFail extends UsersState {
  final Object? error;
  final StackTrace? stackTrace;

  LoadedUsersFail({required this.error, required this.stackTrace});
}

Create a Spread widget subscribed to a state change:

@override
Widget build(BuildContext context) {
    return Spread<AppState>(
      builder: _homeBody,
    );
}

Widget _homeBody(BuildContext context, AppState? state) {
  switch(state) {
    case AppState.posts: {
      return PostsPage();
    }
    case AppState.users:
    default: {
      return UsersPage();
    }
  }
}

Emitting state:

Using the StateEmitter mixin:

import 'package:spread/spread.dart';

class UserManager with StateEmitter {

  void updateUser(User user) {
    emitEntity<User>(user);
  }
}

Observing state:

Extend from the SpreadObserver:

import 'package:spread/spread.dart';

class UserObserver extends SpreadObserver {

  @override
  void onState(User user) {
    print('User updated: ${user.name}');
  }
}

Documentation #

Detailed documentation is available in the source code.

Contributing #

Contributions, issues, and feature requests are welcome! See our contribution guidelines for more information.

License #

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