SwiftRedux

This is a basic implementation of a Redux-style state store in Swift. I started this as part of my WWDC18 submission.

The tool is made up of two key components, a Reducer and a Store. The concept is simple: keep the current application state in the Store, and make updates as necessary using the reducer. You create subscribers which get notified of any changes to the state (as well as the state when they're first assigned!).

Getting Started

SwiftRedux uses Swift Package Manager to automate the process of downloading and linking the framework. An example is included in the repo, however the following Package.swift should get you up and running:

// swift-tools-version:4.0
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "NameOfPackage",
    dependencies: [ 
        .package(url: "https://github.com/jaylees14/SwiftRedux", from: "0.1.0"),
    ],
    targets: [
        .target(
            name: "NameOfPackage",
            dependencies: ["SwiftRedux"]),
    ]
)

Interacting with the Store

The store is written with generics, allowing you to define the State and Action however fits with your project.

Initialisation

Creating the store requires two parameters, a reducer and the initial state of the application.

let store: Store<State, Action> = Store(reducer: reducer, initialState: initialState)

A reducer's job is to take the current state, as well as an action, and combine the two to produce a new state. An example might be:

let reducer: Reducer<State, Action> = Reducer { (state: State, action: Action) -> State in
    var copyState = state
	copyState.property = action
 	return copyState
)}

Dispatching Actions

Now we have a store, we can dispatch actions and reduce them over the current state.

store.dispatch(action)

This will trigger the reducer on the current state and modify it as necessary.

Subscribers

To be notified every time that the state is updated, we can use a subscriber:

store.subscribe { (state) in
	// Deal with the newly updated state                 
}

The subscriber is notified every time an action is dispatched and when it first subscribes to the store.

Running the Example

To run the example, run the following commands in your terminal

$ git clone https://github.com/jaylees14/SwiftRedux.git
$ cd SwiftRedux/Examples/GameBoard
$ swift build
$ swift run