AtlasSwift 0.1.0

AtlasSwift 0.1.0

×

Maintained by Giuseppe Salvo.

AtlasSwift 0.1.0

Atlas Swift Store

Atlas is a redux store for your swift apps without the reducer layer

Version License Platform

Installation

Atlas is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'AtlasSwift'

How it works

there are 3 main components

  • State
  • Actions
  • Guards

State

// The state should be always a struct, to ensure immutability
struct CountState {
    var count: Int
}

let store = Atlas(state: CountState(
    count: 0
))

Actions

Actions can be synchronous or asynchronous

struct Increment: AtlasAction {
    func handle(state: CountState, context: AtlasActionContext<CountState>) {
        var newState   = state
        newState.count = result
        context.complete(newState)
        // context.error(YourError)
    }
}

store.dispatch(Increment())

// With a completition callback
store.dispatch(Increment()) { (error?, state) in
    print("done! ", state.count)
}

Guards

Guards track the store lifecycle. In future, they will include also a middleware-like function.

struct Logger: AtlasGuard {
    // By default, this function returns true
    func shouldUpdate<A: AtlasAction>(state: State, action: A) -> Bool {
        return true
    }

    func willUpdate<A: AtlasAction>(state: State, action: A) {
        print("will update!", state.count)
    }
    
    func didUpdate<A: AtlasAction>(state: State, action: A) {
        print("update!", state.count)
    }
}

let store = Atlas(state: YourState(), guards: [ Logger() ])

Subscription

extension YourController: AtlasSubscriber {

    override func viewDidAppear() {
        super.viewDidAppear()
        store.subscribe(self)
    }
    
    func newState(_ state: CountState) {
        print("count state changed!")
    }
}

Subscriber Should Update

Avoiding unneeded updates and subscribing to a specific part of the store. By default, the shouldUpdate function returns always true. To use this method, the state should be a value type.

extension YourController: AtlasSubscriber {

    // subscription code...

    func shouldUpdate(prevState: CountState?, newState: CountState) -> Bool {
        return prevState?.count != newState.count
    }
}

Notes

  • Atlas uses a serial queue to dispatch every action, so you can be sure that your actions will be executed in the invokation order
  • The dispatch function is async, to avoid deadlocks. To track its end, you can use the completition argument
  • The subcribe function has a second argument "queue", to subscribe a class on a specific queue.

That's all!

Inspired by ReSwift and Redux

License

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