in-app purchase in Swift with a single product

Question

Is there a simple way to implement a in-app purchase in swift for a single product?

I want a button that triggers the in-app purchase like a [ad-removal] or [unlock-premium-content]

I can't understand the full logic of it.

I'm trying to follow and translate this tutorial from [Techotopia] http://www.techotopia.com/index.php/An_iOS_7_In-App_Purchase_Tutorial

But It's my first time with the StoreKit Framework, and also with Swift.

I just want to know the logic of the in-app purchase transaction with the Swift StoreKit Framework.

Thanks!

Answer 1

Step 0: In your iTunes Connect account, create an In-App purchase.

For Single purchases, use this method:

1. Import

import StoreKit 

2. Conform to StoreKit Delegate

class YOURViewController: UIViewController, SKProductsRequestDelegate, SKPaymentTransactionObserver { 

3. Use a user default to track transactions

let defaults = NSUserDefaults.standardUserDefaults() 

4. Product ID. This one will be same as in your iTunes Connect in app purchase

var product_id: NSString?  override func viewDidLoad() {             product_id = "YOUR_PRODUCT_ID"     super.viewDidLoad()     SKPaymentQueue.defaultQueue().addTransactionObserver(self)      //Check if product is purchased      if (defaults.boolForKey("purchased")){          // Hide a view or show content depends on your requirement        overlayView.hidden = true          } else if (!defaults.boolForKey("stonerPurchased")) {         print("false")                 } } 

5. Unlock Content. This is button action which will initialize purchase

@IBAction func unlockAction(sender: AnyObject) {     print("About to fetch the products")     // We check that we are allow to make the purchase.    if (SKPaymentQueue.canMakePayments()) {         var productID:NSSet = NSSet(object: self.product_id!);         var productsRequest:SKProductsRequest = SKProductsRequest(productIdentifiers: productID);         productsRequest.delegate = self;         productsRequest.start();         println("Fetching Products");     } else {         print("can't make purchases");     }     } 

6. Helper Methods

func buyProduct(product: SKProduct) {     println("Sending the Payment Request to Apple");     var payment = SKPayment(product: product)     SKPaymentQueue.defaultQueue().addPayment(payment); } 

7. Delegate Methods for IAP

func productsRequest (request: SKProductsRequest, didReceiveResponse response: SKProductsResponse) {      var count : Int = response.products.count     if (count>0) {         var validProducts = response.products         var validProduct: SKProduct = response.products[0] as SKProduct         if (validProduct.productIdentifier == self.product_id) {             print(validProduct.localizedTitle)             print(validProduct.localizedDescription)             print(validProduct.price)             buyProduct(validProduct);         } else {             print(validProduct.productIdentifier)         }     } else {         print("nothing")     } }      func request(request: SKRequest!, didFailWithError error: NSError!) {     print("Error Fetching product information"); }  func paymentQueue(queue: SKPaymentQueue!, updatedTransactions transactions: [AnyObject]!)    {     print("Received Payment Transaction Response from Apple");      for transaction:AnyObject in transactions {         if let trans:SKPaymentTransaction = transaction as? SKPaymentTransaction{             switch trans.transactionState {             case .Purchased:                 print("Product Purchased");                 SKPaymentQueue.defaultQueue().finishTransaction(transaction as SKPaymentTransaction)                 defaults.setBool(true , forKey: "purchased")                 overlayView.hidden = true                 break;             case .Failed:                 print("Purchased Failed");                 SKPaymentQueue.defaultQueue().finishTransaction(transaction as SKPaymentTransaction)                 break;             case .Restored:                 print("Already Purchased");                 SKPaymentQueue.defaultQueue().restoreCompletedTransactions()                 default:                 break;             }         }     }         } 

Swift > 3.0

import StoreKit class YOURVIEWController:UIViewController, SKProductsRequestDelegate, SKPaymentTransactionObserver {  let product_id: NSString = "com.some.inappid" // <!-- Change it to your inapp id 

In your viewDidLoad add

override func viewDidLoad() {     super.viewDidLoad()     SKPaymentQueue.default().add(self) 

In your buy button action

@IBAction func buyNowAction(_ sender: UIButton) {       if (SKPaymentQueue.canMakePayments()) {         let productID:NSSet = NSSet(array: [self.product_id as NSString]);         let productsRequest:SKProductsRequest = SKProductsRequest(productIdentifiers: productID as! Set<String>);         productsRequest.delegate = self;         productsRequest.start();         print("Fetching Products");     } else {         print("can't make purchases");     } } 

In Your Restore button action

// MARK: - Restore In App Purchase     @IBAction func restoreAction(_ sender: UIButton) {      if (SKPaymentQueue.canMakePayments()) {         SKPaymentQueue.default().add(self)         SKPaymentQueue.default().restoreCompletedTransactions()     } else {         // show error     }  } 

Add Delegates:

// SKProductRequest Delegate  func productsRequest(_ request: SKProductsRequest, didReceive response: SKProductsResponse) {      print(response.products)     let count : Int = response.products.count     if (count>0) {          let validProduct: SKProduct = response.products[0] as SKProduct         if (validProduct.productIdentifier == self.product_id as String) {             print(validProduct.localizedTitle)             print(validProduct.localizedDescription)             print(validProduct.price)             self.buyProduct(product: validProduct)         } else {             print(validProduct.productIdentifier)         }     } else {         print("nothing")     } }  func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {     for transaction:AnyObject in transactions {         if let trans:SKPaymentTransaction = transaction as? SKPaymentTransaction{              self.dismissPurchaseBtn.isEnabled = true             self.restorePurchaseBtn.isEnabled = true             self.buyNowBtn.isEnabled = true              switch trans.transactionState {             case .purchased:                 print("Product Purchased")                 //Do unlocking etc stuff here in case of new purchase                 SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)                  break;             case .failed:                 print("Purchased Failed");                 SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)                 break;             case .restored:                 print("Already Purchased")                 //Do unlocking etc stuff here in case of restor                  SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)             default:                 break;             }         }     } }   //If an error occurs, the code will go to this function     func paymentQueue(_ queue: SKPaymentQueue, restoreCompletedTransactionsFailedWithError error: Error) {         // Show some alert     }