StoreKit Delegate / Observable object in SwiftUI View

问题

When I restored my purchases, I need to disabled the restore button in the view.

I have IAPManager class with SKPaymentTransactionObserver, and it works fine, I saw the print("restored") of SKPaymentTransactionObserver when I call SKPaymentQueue.default().restoreCompletedTransactions from my principal view.

So, then the problem is that from the view I do not find out about that event and therefore I cannot disable the button, since the purchase has already been restored.

In my IAPManager:

func restore(withUsername username: String? = nil) {
    SKPaymentQueue.default().add(self)
    SKPaymentQueue.default().restoreCompletedTransactions(withApplicationUsername: username)
}

extension IAPManager: SKPaymentTransactionObserver {

func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
    transactions.forEach {
        switch $0.transactionState {
        case .purchasing: ()
            print("purchasing")
        case .deferred: ()
            print("deferred")
        case .restored: SKPaymentQueue.default().finishTransaction($0)
            print("restaured")
                UserDefaults.standard.set(true, forKey: "pro")
        case .failed: SKPaymentQueue.default().finishTransaction($0)
            print("failed")
                UserDefaults.standard.set(false, forKey: "pro")
        case .purchased: SKPaymentQueue.default().finishTransaction($0)
            print("purchased")
                UserDefaults.standard.set(true, forKey: "pro")
        @unknown default:
            break
        }
    }

}

In my View:

Text("Available purchases").font(.title3).foregroundColor(.green)
  .onTapGesture {
    IAPManager.shared.getProducts()
  }.padding()
Spacer()
  Button(action: {
    let purchased = UserDefaults.standard.bool(forKey: "pro")
    if !purchased {
        print("Going to try restore")
        IAPManager.shared.restore()
    } else {
        print("restored!")
    }
  }){
    Text((buyed ? "Restored"  : "Restore" ))
        .fontWeight(.bold)
           .font(.none)
           .padding(6)
           .cornerRadius(40)
           .foregroundColor(.blue)
           .overlay(
               RoundedRectangle(cornerRadius: 40)
                .stroke(Color.blue, lineWidth: 0.8)
           )
  }.buttonStyle(PlainButtonStyle())
  .disabled(  UserDefaults.standard.bool(forKey: "pro"))
  .padding()

回答1:

For communication between unrelated and already existing components you can use custom Notifications.

Create a name for your Notification:

extension IAPManager {
    static let proNotification = Notification.Name(rawValue: "proNotification")
}

In the place where you restore your transactions, send out the notification informing all subscribers that the Pro is restored:

case .restored: 
    print("restored")
    SKPaymentQueue.default().finishTransaction($0)
    NotificationCenter.default.post(name: IAPManager.proNotification, object: nil, userInfo: nil)

Now you need a way to observe this notification::

struct ContentView: View {
    @State var isPro = false
    
    var body: some View {
        Text(isPro ? "pro user" : "standard user")
            .onReceive(NotificationCenter.default.publisher(for: IAPManager.proNotification)) { _ in
                self.isPro = true
            }
    }
}

来源：https://stackoverflow.com/questions/63919916/storekit-delegate-observable-object-in-swiftui-view

标签

ios

swiftui

storekit