Reference to generic type when returning view that uses a protocol-CodePudding

I am being unable to return a View that uses a protocol as a dependency as this is throwing me Reference to generic type 'LoginView' requires arguments in <...>.

func makeLoginView(viewModel: LoginViewModelType) -> LoginView {
    return LoginView(viewModel: viewModel)
}

My LoginView uses LoginViewModelType as I have two different view models.

protocol LoginViewModelType: ObservableObject {
    var bookingPaymentViewModel: BookingPaymentViewModel? { get }

    var email: String { get set }
    var password: String { get set }\
    ...

    func login()
}

struct LoginView<ViewModel: LoginViewModelType>: View {
    @ObservedObject var viewModel: ViewModel

    var body: some View {
        ...
    }

I can't understand what I am doing wrong, the LoginView should be able to return a View regardless as it complies to LoginViewModelType.

CodePudding user response：

You need to constrain makeLoginView to accept a generic of type LoginViewModelType and then use that same generic in the returned value.

class BookingPaymentViewModel { }

func makeLoginView<T:LoginViewModelType>(viewModel: T) -> LoginView<T> {
    return LoginView(viewModel: viewModel)
}

protocol LoginViewModelType: ObservableObject {
    var bookingPaymentViewModel: BookingPaymentViewModel? { get }

    var email: String { get set }
    var password: String { get set }

    func login()
}

struct LoginView<ViewModel: LoginViewModelType>: View {
    @ObservedObject var viewModel: ViewModel

    var body: some View {
        Text("test")
    }
}