Pike

Pike is a state management library for Flutter based on the Event-Driven pattern. It uses event streams to manage state and provides convenient components for interacting with the state, such as PikeBuilder, PikeConsumer, and PikeProvider.

Features

• State management using events: The state is updated in response to events.
• Components for listening to and displaying state: PikeBuilder, PikeConsumer, and PikeProvider are used to manage and display state changes.
• Customizable event handling: Allows for custom event handlers and selective state rebuilds.

Installation

Add pike to your pubspec.yaml file:

dependencies:
  pike: ^latest_version

Usage

Creating a Pike instance

Create a Pike instance by passing an initial state:

final class MockPike extends Pike<Event, State> {
  MockPike() : super(InitialState()) {
    on<Event>((event, emit) => switch(event) {
      FetchEvent() => _callback(event, emit),
      FetchWithExceptionEvent() => _callbackA(event, emit),
    });

  }

  Future<void> _callback(FetchEvent event, Emit<State> emit) async {
    emit(LoadedState());
  }

  void _callbackA(FetchWithExceptionEvent event, Emit<State> emit) {
    emit(ExceptionState());
  }
}

// Events

sealed class Event {}

class FetchEvent extends Event {}

class FetchWithExceptionEvent extends Event {}

// States

sealed class State {}

class InitialState extends State {}

class LoadedState extends State {}

class ExceptionState extends State {}

Adding events

Add events to the Pike instance to trigger state changes:

pike.add(MyEvent());

Listening to state changes

Use PikeBuilder or PikeConsumer to rebuild your widgets when the state changes:

PikeBuilder<MyPike, MyState>(
  builder: (context, state) {
    return Text('Current State: $state');
  },
);

Providing the Pike instance

Wrap your widget tree with PikeProvider to provide the Pike instance to the widgets:

PikeProvider<MyPike>(
  pike: pike,
  child: MyWidget(),
);

Custom event handling with PikeObserver

You can implement PikeObserver to track the lifecycle and events of your Pike instances:

class MyPikeObserver extends PikeObserver {
  @override
  void onCreate<P extends Pike<Object?, Object?>>(P pike) {
    print("Pike created");
  }

  @override
  void onEvent<P extends Pike<Object?, Object?>, Event>(
    P pike,
    Event event,
  ) {
    print("Event occurred: $event");
  }
}

Components

PikeBuilder

A widget that listens to state changes and rebuilds when the state updates.

PikeBuilder<MyPike, MyState>(
  builder: (context, state) {
    return Text('Current State: $state');
  },
);

PikeConsumer

A widget that listens to state changes and provides a custom listener to trigger side effects.

PikeConsumer<MyPike, MyState>(
  builder: (context, state) {
    return Text('Current State: $state');
  },
  listener: (context, state) {
    // Handle side effects here
  },
);

PikeProvider

A widget that provides a Pike instance to its descendants.

PikeProvider<MyPike>(
  pike: pike,
  child: MyWidget(),
);

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