Restore InApp purchase using swift, iOS - ios

Question

I am implementing restore in app purchase. I have a button whose action is
#IBAction func restorePurchases(send : AnyObject){
SKPaymentQueue.defaultQueue().restoreCompletedTransactions()
// if (success) {
// I want to do something here
// }
}
My question is.
Is this the right way to restore?
How can we verify success action for restoring purchases?

Answer 1

don't forget to check if you can make a payment:
if (SKPaymentQueue.canMakePayments()) {
SKPaymentQueue.default().restoreCompletedTransactions()
}
for check if the restore was good you have to follow the protocol:
SKPaymentTransactionObserver
and then implement the method:
func paymentQueue(queue: SKPaymentQueue!, updatedTransactions transactions: [AnyObject]!)
and subscribe to the event by doing:
SKPaymentQueue.default().add(self)
Finally here is an exemple of how I check the result:
func paymentQueue(_ queue: SKPaymentQueue!, updatedTransactions transactions: [AnyObject]!) {
print("Received Payment Transaction Response from Apple");
for transaction in transactions {
switch transaction.transactionState {
case .purchased, .restored:
print("Purchased purchase/restored")
SKPaymentQueue.default().finishTransaction(transaction as SKPaymentTransaction)
break
case .failed:
print("Purchased Failed")
SKPaymentQueue.default().finishTransaction(transaction as SKPaymentTransaction)
break
default:
print("default")
break
}
}
}

Answer 2

For some reason, even after trying SKPaymentQueue.default().restoreCompletedTransactions() the following function was never called for me during restoration.
func paymentQueue(queue: SKPaymentQueue!,
updatedTransactions transactions: [AnyObject]!)
This line of code SKPaymentQueue.default().add(self) was added to make my class the observer and still no updates.
It seems that this function gets called with the restored scenario if you try to make a payment all over again and the StoreKit API automatically decides if this should be purchased or restored and shows the message accordingly.
Even thought from a user's point of view, they are not charged again, Apple rejected our app because the restore scenario was not added.
So it seems if you call SKPaymentQueue.default().restoreCompletedTransactions() in your code, handle these additional StoreKit delegates to manage your restoration:
func paymentQueueRestoreCompletedTransactionsFinished(_ queue: SKPaymentQueue) {
handleSuccess()
}
func paymentQueue(_ queue: SKPaymentQueue,
restoreCompletedTransactionsFailedWithError error: Error) {
handleError()
}