Store

Unidirectional data flow state management library.

Document

contents

• Store
  • contents
  • Requirements
  • Overview
  • Communication
  • Installation
    • Swift Package Manager
    • Manually
  • Usage
    • Quick Start

Requirements

• iOS 13.0+
• tvOS 13.0+
• macOS 10.15+
• watchOS 7.0+
• Swift 5.7+

Overview

Unidirectional data flow state management library.

Communication

• If you found a bug, open an issue.
• If you have a feature request, open an issue.
• If you want to contribute, submit a pull request.

Installation

Swift Package Manager

Swift Package Manager is a tool for managing the distribution of Swift code. It’s integrated with the Swift build system to automate the process of downloading, compiling, and linking dependencies.

To integrate Store into your Xcode project using Swift Package Manager, add it to the dependencies value of your Package.swift:

dependencies: [
    .package(url: "https://github.com/GSM-MSG/Store.git", .upToNextMajor(from: "1.0.0"))
]

Manually

If you prefer not to use either of the aforementioned dependency managers, you can integrate MSGLayout into your project manually.

Usage

Quick Start

import Combine
import Store
import UIKit

// MARK: - Store
final class SampleStore: Store {
    struct State: Equatable {
        var count: Int = 0
    }

    enum Action {
        case plusButtonDidTap
        case minusButtonDidTap
    }

    enum Mutation {
        case updateCount(Int)
    }

    var stateSubject: CurrentValueSubject<State, Never>
    var initialState: State
    var subscription: Set<AnyCancellable> = .init()

    init(initialState: State) {
        self.initialState = initialState
        self.stateSubject = CurrentValueSubject(initialState)
    }

    func mutate(state: State, action: Action) -> SideEffect<Mutation, Never> {
        switch action {
        case .plusButtonDidTap:
            return .tryAsync { [count = state.count] in
                try await Task.sleep(for: .milliseconds(500))
                return .updateCount(count + 1)
            }
            .catchToNever()

        case .minusButtonDidTap:
            return .just(.updateCount(state.count - 1))

        default :
            return .none
        }
        return .none
    }

    func reduce(state: State, mutate: Mutation) -> State {
        var newState = state
        switch mutate {
        case let .updateCount(count):
            newState.count = count
        }
        return newState
    }
}

// MARK: - ViewController
final class SampleViewController: UIViewController {
    let store: SampleStore
    var subscription: Set<AnyCancellable> = .init()

    init() {
        self.store = .init(initialState: .init())
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private let countLabel: UILabel = {...}()
    private let plusButton: UIButton = {...}()
    private let minusButton: UIButton = {...}()

    override func viewDidLoad() {
        super.viewDidLoad()

        ...

        plusButton.addAction(UIAction(handler: { [weak self] _ in
            self?.store.send(.plusButtonDidTap)
        }), for: .touchUpInside)

        minusButton.addAction(UIAction(handler: { [weak self] _ in
            self?.store.send(.minusButtonDidTap)
        }), for: .touchUpInside)

        store.state.map(\.count)
            .map(String.init)
            .assign(to: \.text, on: countLabel)
            .store(in: &subscription)
    }
}