In-app purchase ios sending more transactions than needed - ios

Question

Im using in-app purchase in SpriteKit. The first transaction does fine, but when i do the second one my
func paymentQueue(queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction])
called 2 times, than 3,4,5
so i do one request but there it adds 100 coins instead of 50...
i gues the problem in that function:
func buyProduct() {
print("buy +" + p.productIdentifier)
var payment = SKMutablePayment(product: p)
SKPaymentQueue.defaultQueue().addTransactionObserver(self)
SKPaymentQueue.defaultQueue().addPayment(payment)
}
i also have :
func productsRequest(request: SKProductsRequest, didReceiveResponse response: SKProductsResponse) {
var myProduct = response.products
for product in myProduct {
list.append(product)
print("product added")
print(product.productIdentifier)
print(product.localizedTitle)
}
print("list is \(list)")
}
func paymentQueue(queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
print(transactions.count)
for transaction in transactions {
print(transaction.error)
switch transaction.transactionState {
case .Purchased:
MBProgressHUD.hideAllHUDsForView(self.view, animated: true)
print("buyed")
print(p.productIdentifier)
let prodID = p.productIdentifier
switch prodID {
case "com.addCoins" :
print("increaing coinsCount")
coinsCount = coinsCount + 50
let userDefaults = NSUserDefaults.standardUserDefaults()
userDefaults.setInteger(coinsCount, forKey: "coins")
userDefaults.synchronize() // don't forget this!!!!
coinsLabel.text = String(coinsCount)
default: print("IAD not setuped")
}
print("premium added")
queue.finishTransaction(transaction)
break
case .Failed:
MBProgressHUD.hideAllHUDsForView(self.view, animated: true)
print("buy error")
queue.finishTransaction(transaction)
break
default: break
}
}
}
im calling purchase with:
for product in list {
let loadingNotification = MBProgressHUD.showHUDAddedTo(self.view, animated: true)
loadingNotification.mode = MBProgressHUDMode.Indeterminate
loadingNotification.labelText = "Loading"
let prodID = product.productIdentifier
if prodID == "com.addCoins" {
p = product
buyProduct()
break
}
}

Answer 1

At some point you have to tell Apple that a purchase has been carried out and you delivered the goods. Until then, the purchases stay in the transaction queue forever.

Answer 2

Its bad practice to add
SKPaymentQueue.defaultQueue().addTransactionObserver(self)
everytime you buy something. You should add the transaction observer at app launch and remove it when your app is closed, as per apples recommended guidelines.
Also you dont need to call synchronise for your userDefaults anymore since iOS 8, yet I still see a lot of people doing it.
In regards to you problem the code seems to be ok. The only thing I noticed so far is why in the buy function are you adding a SKMutablePayment?
Try changing SKMutablePayment to SKPayment and see if it makes a difference.
func buyProduct() {
print("buy +" + p.productIdentifier)
var payment = SKPayment(product: p)
SKPaymentQueue.defaultQueue().addTransactionObserver(self) // should not be here
SKPaymentQueue.defaultQueue().addPayment(payment)
}