https://github.com/inamiy/RxAutomaton

🤖 RxSwift + State Machine, inspired by Redux and Elm.
https://github.com/inamiy/RxAutomaton

automaton elm redux rxswift state-machine swift

Last synced: 3 months ago
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🤖 RxSwift + State Machine, inspired by Redux and Elm.

• Host: GitHub
• URL: https://github.com/inamiy/RxAutomaton
• Owner: inamiy
• License: mit
• Archived: true
• Created: 2016-08-17T12:30:05.000Z (about 8 years ago)
• Default Branch: swift/5.0
• Last Pushed: 2021-12-12T05:06:19.000Z (almost 3 years ago)
• Last Synced: 2024-04-23T19:19:13.730Z (6 months ago)
• Topics: automaton, elm, redux, rxswift, state-machine, swift
• Language: Swift
• Homepage:
• Size: 328 KB
• Stars: 718
• Watchers: 20
• Forks: 31
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
## NOTE: This repository has been discontinued in favor of [Actomaton](https://github.com/inamiy/Actomaton).

# RxAutomaton

[RxSwift](https://github.com/ReactiveX/RxSwift) port of [ReactiveAutomaton](https://github.com/inamiy/ReactiveAutomaton) (State Machine).

>

> ### Terminology

>

> Whenever the word "signal" or "(signal) producer" appears (derived from [ReactiveCocoa](https://github.com/ReactiveCocoa/ReactiveCocoa)), they mean "hot-observable" and "cold-observable".

## Example

(Demo app is bundled in the project)

![](Assets/login-diagram.png)

To make a state transition diagram like above _with additional effects_, follow these steps:

```swift

// 1. Define `State`s and `Input`s.

enum State {

    case loggedOut, loggingIn, loggedIn, loggingOut

}

enum Input {

    case login, loginOK, logout, logoutOK

    case forceLogout

}

// Additional effects (`Observable`s) while state-transitioning.

// (NOTE: Use `Observable.empty()` for no effect)

let loginOKProducer = /* show UI, setup DB, request APIs, ..., and send `Input.loginOK` */

let logoutOKProducer = /* show UI, clear cache, cancel APIs, ..., and send `Input.logoutOK` */

let forcelogoutOKProducer = /* do something more special, ..., and send `Input.logoutOK` */

let canForceLogout: State -> Bool = [.loggingIn, .loggedIn].contains

// 2. Setup state-transition mappings.

let mappings: [Automaton.EffectMapping] = [

  /*  Input      |   fromState => toState        |      Effect       */

  /* ----------------------------------------------------------------*/

    .login       | .loggedOut  => .loggingIn     | loginOKProducer,

    .loginOK     | .loggingIn  => .loggedIn      | .empty(),

    .logout      | .loggedIn   => .loggingOut    | logoutOKProducer,

    .logoutOK    | .loggingOut => .loggedOut     | .empty(),

    .forceLogout | canForceLogout => .loggingOut | forceLogoutOKProducer

]

// 3. Prepare input pipe for sending `Input` to `Automaton`.

let (inputSignal, inputObserver) = Observable.pipe()

// 4. Setup `Automaton`.

let automaton = Automaton(

    state: .loggedOut,

    input: inputSignal,

    mapping: reduce(mappings),  // combine mappings using `reduce` helper

    strategy: .latest   // NOTE: `.latest` cancels previous running effect

)

// Observe state-transition replies (`.success` or `.failure`).

automaton.replies.subscribe(next: { reply in

    print("received reply = \(reply)")

})

// Observe current state changes.

automaton.state.asObservable().subscribe(next: { state in

    print("current state = \(state)")

})

```

And let's test!

```swift

let send = inputObserver.onNext

expect(automaton.state.value) == .loggedIn    // already logged in

send(Input.logout)

expect(automaton.state.value) == .loggingOut  // logging out...

// `logoutOKProducer` will automatically send `Input.logoutOK` later

// and transit to `State.loggedOut`.

expect(automaton.state.value) == .loggedOut   // already logged out

send(Input.login)

expect(automaton.state.value) == .loggingIn   // logging in...

// `loginOKProducer` will automatically send `Input.loginOK` later

// and transit to `State.loggedIn`.

// 👨🏽 < But wait, there's more!

// Let's send `Input.forceLogout` immediately after `State.loggingIn`.

send(Input.forceLogout)                       // 💥💣💥

expect(automaton.state.value) == .loggingOut  // logging out...

// `forcelogoutOKProducer` will automatically send `Input.logoutOK` later

// and transit to `State.loggedOut`.

```

## License

[MIT](LICENSE)