Fluxer

Flux + ViewModel framework for SwiftUI (inspired by ReactorKit)

(⚠️ Don't use in production yet)

Requirements

Swift 5.2+
iOS 13+

Installation

Fluxer only support Swift Package Manager

Usage

1. Create ViewModel

import Foundation
import Combine
import SwiftUI
import Fluxer

final class ContentViewModel: ViewModel {
    enum Action {
        case increase
        case decrease
    }

    enum Mutation {
        case increaseValue
        case decreaseValue
    }

    class State: ObservableObject {
        @Published var number = 0
    }

    @Published var state = State()

    init() {
        // Don't forget to call this function
        initilize()
    }

    func mutate(action: Action) -> AnyPublisher<Mutation, Never> {
        switch action {
        case .increase:
            return Just(Mutation.increaseValue).eraseToAnyPublisher()
        case .decrease:
            return Just(Mutation.decreaseValue).eraseToAnyPublisher()
        }
    }

    func reduce(mutation: Mutation) {
        switch mutation {
        case .increaseValue:
            state.number += 1
        case .decreaseValue:
            state.number -= 1
        }
    }
}

2. Instantiate ViewModel in View

import SwiftUI

struct ContentView: View {
    @ObservedObject var viewModel: ContentViewModel

    var body: some View {
        HStack {
            Button(viewModel: viewModel, action: .decrease) {
                Text("-")
            }
            .font(Font.system(size: 80, weight: .regular))
            TextField("", value: $viewModel.state.number, formatter: NumberFormatter())
                .multilineTextAlignment(.center)
                .disabled(true)
                .frame(width: 200)
                .font(Font.system(size: 40, weight: .regular))
            Button(viewModel: viewModel, action: .increase) {
                Text("+")
            }
            .font(Font.system(size: 80, weight: .regular))
        }
    }
}

Fluxer have some useful initializers for Views.

The following two codes have the same meaning.

Button(viewModel: viewModel, action: .decrease) {
    Text("-")
}

Button(action: {
    viewModel.action.send(.decrease)
}) {
    Text("-")
}

Demo

$ open Fluxer.xcodeproj/