NavigationState

Installation

Swift Package Manager

https://github.com/alexflm/navigation-state-swiftui

Setup

First you need to create an AppNavigation class, which will store all your scenes.

class AppNavigation: NavigationState<AppNavigation.State> {
    enum State: Equatable {
        case paywallPLUS
        case messages
        case profile
        case photo(data: Photo)
        case nextScene(scene: HashableAnyView)
        //nextScene is needed so that you can create Flow from several scenes, where the future scene is not known in advance.
        
        static func == (lhs: AppNavigation.State, rhs: AppNavigation.State) -> Bool {
            switch (lhs, rhs) {
            case (nextScene(let s1), nextScene(let s2)):
                return s1.id == s2.id
                
            case (photos(let p1), photos(let p2)):
                return p1.id == p1.id
                
            default:
                return false
            }
        }
    }
}

Usage with View

1. Initialize navigation. You need to initialize an object for every scene.

@StateObject var navigation = AppNavigation()

2. Add modifier navigation

VStack {
  ...
}
.navigation(type: navigation.presentType, item: $navigation.state) { state in
    switch state {
    case .yellow:
        YellowView()
                
    case .green:
        GreenView()
                
    case .blue:
        BlueView { _ in
            navigation.dismiss()
        }
                
    default:
        EmptyView()
    }
}

3. There are 2 ways to create a dismiss from a childView.

The first option is basic.

@Environment(\.dismiss) var dismiss

You can also dismiss from the root view using navigation.

navigation.dismiss()

Usage with ViewModel

If you want to initialize navigation in the viewModel, you need to add an observer so that the view model can notify the view of changes.

class ViewModel: ObservableObject {
        
    @Published var navigation = AppNavigation()
    var cancellable = Set<AnyCancellable>()
    
    // The load function must be called in the onAppear of the view.
    func load() {
        navigation.observer(self.objectWillChange)
            .store(in: &cancellable)
    }        
}

Flow

A flexible option is to create a view, where the view is not dependent on other views.

In order to create your own Flows, you need to add completion to the view.

var completion: NavigationCompletion

By clicking on the button, you set the navigation options.

Button("Dismiss") {
    completion { state in
        switch state {
        case .dismiss(let completion):
            completion?()
                        
        case .push(let scene):
            navigation.show(type: .push, state: .nextScene(scene: .init(scene)))
        }
    }
}

Example flow

func progressFlow(data: Progress, allowAd: Bool, navigationCompletion: @escaping NavigationCompletion) -> some View {
    self.progressView(data: data) {
        if allowAd, !UserDefaults.isPlusVersion {
            $0(.push(scene: AnyView(self.makeFullScreenAdNativeView(navigationCompletion: navigationCompletion))))
        } else {
            navigationCompletion($0)
        }
    }
}

License

This library is released under the MIT license. See LICENSE for details.