May I ask how I can receive a bool result in my view controller like func validateUser(username: String?, password: String?) -> AnyPublisher<Bool, Never> { if let username = username, let password = password { if !username.isEmpty && !password.isEmpty { // true } } } , please?

I don't know if my approach in reading view model data is correct. At least, I don't think it's efficient in the view controller.

It seems that I have achieved my objective with the following. But I'm not sure if it's an efficient approach. import SwiftUI struct ContentView: View { @State var numbers = [2021, 9, 30] var body: some View { let firstLocalYear = 2021 let firstLocalMonth = 9 let firstLocalDay = 24 let firstLastDay = 30 NavigationView { List { Section(header: Text("Current month")) { ForEach(firstLocalDay ..< firstLastDay) { i in HStack { Text("\(firstLocalMonth)-\(i + 1)") Spacer() Button("Select") { self.numbers = [firstLocalYear, firstLocalMonth, i + 1] } NavigationLink( destination: TimeView(numbers: $numbers), label: { Text("") }) } } } } } } } struct TimeView: View { @Binding var numbers: [Int] var body: some View { HStack { Text(String(numbers[0])) Text(String(numbers[1])) Text(String(numbers[2])) } } }

Oops... Silly me... If it's logged in, I only show Text("Yes, I'm logged in")

Probably not because this EnvironmetValue is not dichotomous?

Are you talking about Apple's marketing resources??

Oh, I see. Silly me... Thanks a lot.

What I should have done is the following. override func viewDidLoad() { super.viewDidLoad() cancellable = $segmentNumber.receive(on: DispatchQueue.main) .sink(receiveValue: { (number) in self.actionButton.isEnabled = (number == 0) ? false : true }) } Silly me...

I guess it's a dumb question. segmentNumber is not a bool object.

I guess I can use Internal Testing.

If you allow them to make a purchase, you do have to use the IAP system, I suppose. I don't know if children are allowed to use this type of apps, though. See if you are eligible for a commission waiver.