Why is paymentQueue(_:shouldAddStorePayment:_:) not being called? - ios

Question

Why is paymentQueue(:shouldAddStorePayment::) not being called?
I am sure I've done everything I need to do.
I declared my own class that supports the SKPaymentTransactionObserver protocol:
import UIKit
import StoreKit
import AudioToolbox.AudioServices
class UTIPaymentTransactionObserver: NSObject, SKPaymentTransactionObserver {
func paymentQueue(_ queue: SKPaymentQueue, shouldAddStorePayment payment: SKPayment, for product: SKProduct) -> Bool {
print("!!! shouldAddStorePayment")
AudioServicesPlayAlertSound(kSystemSoundID_Vibrate)
return false
}
func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
print("!!! updatedTransactions")
for transaction in transactions {
print("!!! transaction=", transaction)
switch transaction.transactionState {
// Call the appropriate custom method for the transaction state.
case SKPaymentTransactionState.purchasing:
showTransactionAsInProgress(transaction, deferred: false)
case SKPaymentTransactionState.deferred:
showTransactionAsInProgress(transaction, deferred: true)
case SKPaymentTransactionState.failed:
failedTransaction(transaction)
case SKPaymentTransactionState.purchased:
completeTransaction(transaction)
case SKPaymentTransactionState.restored:
restoreTransaction(transaction)
}
}
}
func showTransactionAsInProgress(_ transaction: SKPaymentTransaction, deferred: Bool) {
print("!!! showTransactionAsInProgress")
}
func failedTransaction(_ transaction: SKPaymentTransaction) {
print("!!! failedTransaction")
SKPaymentQueue.default().finishTransaction(transaction)
}
func completeTransaction(_ transaction: SKPaymentTransaction) {
print("!!! completeTransaction")
SKPaymentQueue.default().finishTransaction(transaction)
}
func restoreTransaction(_ transaction: SKPaymentTransaction) {
print("!!! restoreTransaction")
}
}
I added code to vibrate the device when paymentQueue(:shouldAddStorePayment::) is called to indicate that the method is actually called.
I declared an instance of the observer class globally:
internal let paymentTransactionObserver = UTIPaymentTransactionObserver()
I made sure I added the observer in AppDelegate:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
SKPaymentQueue.default().add(paymentTransactionObserver)
return true
}
The print statement in the paymentQueue(:shouldAddStorePayment::) method never prints and the device never vibrates. It doesn't look like that method is called.
The paymentQueue(_:updatedTransactions:) method is called. The print statement in that method executed.
In this code I returned false for the paymentQueue(:shouldAddStorePayment::) method, but it doesn't make a difference. The process goes through just as if I returned a true. The product had already been purchased before, so it goes through and lets the user/tester purchase it again.
Any help would be appreciated.
Here is code extension for the view controller that retrieves the product from App Store and presents my user interface that allows the user to purchase the product:
I call validateProductIdentifiers() to start the process of selling the product to the user.
// MARK: - SKProductsRequestDelegate
extension CloudViewController: SKProductsRequestDelegate {
func validateProductIdentifiers() {
let url = Bundle.main.url(forResource: "Purchase", withExtension: "plist")!
let nsArrayProductIdentifiers: NSArray = NSArray(contentsOf: url)!
let productIdentifiers = nsArrayProductIdentifiers as! [String]
print(productIdentifiers)
let setProductIdentifers: Set = Set(productIdentifiers)
let productsRequest = SKProductsRequest(productIdentifiers: setProductIdentifers)
self.productsRequest = productsRequest
productsRequest.delegate = self
productsRequest.start()
}
func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {
print("!!! didReceive")
self.products = response.products
let alertMessage = "Would you like to purchase?"
let alert = UIAlertController(title: nil, message: alertMessage, preferredStyle: .actionSheet)
let actionYes = UIAlertAction(title: "Yes", style: .default) {
action in
// Purchase
let product: SKProduct = response.products.first!
let payment: SKMutablePayment = SKMutablePayment(product: product)
SKPaymentQueue.default().add(payment)
}
let actionNo = UIAlertAction(title: "No", style: .cancel, handler: nil)
alert.addAction(actionYes)
alert.addAction(actionNo)
alert.popoverPresentationController?.barButtonItem = barButtonItemEnableDropbox
present(alert, animated: true, completion: nil)
}
}

Answer 1

As per the documentation for this method
This delegate method is called when the user starts an in-app purchase in the App Store, and the transaction continues in your app. Specifically, if your app is already installed, the method is called.
This occurs when a user redeems a promo code for an in-app purchase in the App Store app or purchases a promoted in-App purchase in the App Store app.
It is not called when the purchase is initiated in your app, since you already have control over whether purchasing should be permitted when the user is in your app.