How to execute an action conditionally?

[Jerry-Wang-Developer]

Look forward for best practice for below scenario.

Let say I have a Root state holding login information and some child state.
For child state, some action need to perform after login. that is, if the user is not login, we need to show the login page for user to login, and after login.

The below is a very simple codes.

When Child View button click, The code execution is always ③ ① ② , But for my scenario, I want ③ ① execute execept ② when user is not login, How can I do that?
If can't, What is the best practice to handle this scenario. (I know the key problem is that how can I share some state(here is isLogin) among the app, Think about that will be many child states and in there lots of action need user login first to forward process.)

struct Root: ReducerProtocol {
    struct State: Equatable, Codable {
        var child: Child.State
        var isLogin: Bool
        var showLoginPage: Bool
    }

    enum Action: Equatable {
        case child(Child.Action)
    }
    
    var body: some ReducerProtocol<State, Action> {
        Reduce { state, action in
            switch action {
            case .child(.favorite): // ①
                if !state.isLogin {
                    // In this case, I want to show login page and prevent ② to execute, How to do that?
                    state.showLoginPage = true
                    return .none  
                }
                return .none

            default:
                return .none
            }
        }

        Scope(state: \.child, action: /Action.child) {
            Child()
        }
    }
}

struct Child: ReducerProtocol {
    struct State: Equatable {
        var isFavorite: Bool
    }
    
    enum Action {
        case favorite(Bool)
    }
    
    var body: some ReducerProtocol<State, Action> {
        Reduce { state, action in
            switch action {
            case let .favorite(isFavorite): // ②
                state.isFavorite = isFavorite
                return .none
            }
        }
    }
}


struct ChildView: View {
    let store: StoreOf<Child>
    
    var body: some View {
        WithViewStore(store) { viewStore in
            Button {
                viewStore.send(.favorite) // ③
            } label: {
                Text("favorite")
            }
        }
    }
}

[jeffersonsetiawan]

For this case, I usually store the isLoggedIn outside the state, and you can call it via the dependency.

struct Child: ReducerProtocol {
    struct State: Equatable {
        var isFavorite: Bool
    }
    
    enum Action {
        case favorite(Bool)
    }
    @Dependency(\.isLoggedIn) var isLoggedIn
    var body: some ReducerProtocol<State, Action> {
        Reduce { state, action in
            switch action {
            case let .favorite(isFavorite): // ②
                guard isLoggedIn else { return .none }
                state.isFavorite = isFavorite
                return .none
            }
        }
    }
}

[Jerry-Wang-Developer]

Typically, I have a login view and I'd like to pass a LoginState with isLogin property to that view for further operate on it, if the isLogin outside the state, the view have to change the isLogin property directly and which is contrary to the rule that state should change via action.

[jay-handhug]

I think you can delegate the logic ② to its parent to execute instead of executing in the child