FluxxKit

Overview

Unidirectional data flow for reactive programming in iOS.

Porting facebook’s flux implementation in Swift, except callback called when store changes.

Why no callback?

We have RxSwift, ReactiveSwift, ReactiveKit or something else. All the stateful things could be implemented as Observable or Stream, and ViewController could bind and react to them.

Example

To run the example project, clone the repo, and run pod install from the Example directory first.

More complicated real world example like below is here.

Getting Started

1. State

import FluxxKit
import RxSwift

final class ViewModel: StateType {
  var count = Observable<Int>(0)
}

2. Action

extension ViewModel {
  enum Action: ActionType {
    case plus
    case minus
  }
}

3. Reducer

extension ViewModel {
  final class Reducer: FluxxKit.Reducer<ViewModel, Action> {
    override func reduce(state: ViewModel, action: Action) {

      switch action {
      case .plus:
        state.count.value = state.count + 1
      case .minus:
        state.count.value = state.count - 1
      }
    }
  }
}

4. View

Create store and register it to dispatcher, and bind store’s state:

import FluxxKit
import RxSWift

final class ViewController: UIViewController {

  @IBOutlet var counterLabel: UILabel!
  @IBOutlet var plusButton: UIButton!
  @IBOutlet var minusButton: UIButton!
  var store = Store<ViewModel, ViewModel.Action>(
    reducer: ViewModel.Reducer()
  )

  override func viewDidLoad() {
    super.viewDidLoad()

    Dispatcher.shared.register(store: self.store)

    store.state.count.asObservable().onserveOn(MainScheduler.instance)
      .subscribe(onNext: { [weak self] count in
        self?.counterLabel.text = "\(count)"
      })
  }

  deinit {
    Dispatcher.shared.unregister(identifier: self.store.identifier)
  }
}

Dispatch action with UI action:

@IBAction
func onTouchPlusButton(sender: Any) {
  Dispatcher.shared.dispatch(action: ViewModel.Action.plus)
}

@IBAction
func onTouchMinusButton(sender: Any) {
  Dispatcher.shared.dispatch(action: ViewModel.Action.minus)
}

Architecture

(👻 nice diagram here 👻)

Flux

View -> Action -> Dispatcher -> (Middleware) -> Store -> Reducer -> Observable

• When a user interacts with a View(Controller), it propagates an Action
• through a central Dispatcher,
• to the various Stores that hold the application’s data,
• state transition occurs in some Store that could responds to dispatched Action,
• which will emit new items to Observable property in these Store.

Reactive Programming

Observable ---> View

• ViewController subscribes Store’s Observable properties,
• and react to it.

Requirements

iOS 9 or later. Swift3.0 or later.

Installation

FluxxKit is available through CocoaPods or Carthage.

Author

keitaoouchi, [email protected]

License

FluxxKit is available under the MIT license. See the LICENSE file for more info.