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Full Line by Line Code for In-App Purchase from SwiftStoreKit GitHub in Swift

Full Line by Line Code for In-App Purchase from SwiftStoreKit GitHub in Swift

In-App Purchase from SwiftStoreKit


Introduction

In-app purchases have become a popular revenue generation strategy for mobile app developers. Implementing in-app purchase functionality can be complex, but fortunately, there are open-source libraries available to simplify the process. One such library is SwiftStoreKit, which provides a convenient way to handle in-app purchases in Swift-based iOS applications. In this article, we will guide you through the full line-by-line code for integrating in-app purchase functionality using SwiftStoreKit from GitHub in Swift.

Table of Contents

  1. Getting Started with SwiftStoreKit
  2. Initializing the StoreKit
  3. Setting Up Product Identifiers
  4. Fetching Available Products
  5. Purchasing a Product
  6. Handling Transactions
  7. Restoring Purchases
  8. Verifying Receipts
  9. Displaying Subscription Information
  10. Handling Errors
  11. FAQs
  12. Conclusion

Getting Started with SwiftStoreKit

To get started, you'll need to include the SwiftStoreKit library in your Xcode project. You can do this by adding the following line to your Podfile:

pod 'SwiftStoreKit'

Then, run the pod install command in your project's directory to install the library.

Initializing the StoreKit

Once you have SwiftStoreKit installed, you need to initialize the StoreKit framework in your app. To do this, add the following code to your app delegate's didFinishLaunchingWithOptions method:

import StoreKit func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool { // Other app initialization code // Initialize StoreKit let productIdentifiers: Set<String> = ["com.example.app.product1", "com.example.app.product2"] SwiftStoreKit.shared.start(productIds: productIdentifiers) return true }

Make sure to replace "com.example.app.product1" and "com.example.app.product2" with your actual product identifiers.

Setting Up Product Identifiers

Product identifiers are unique identifiers assigned to each in-app purchase product you want to offer in your app. You need to set up the product identifiers before fetching available products or making a purchase. Add the following code to set up product identifiers:

let productIdentifiers: Set<String> = ["com.example.app.product1", "com.example.app.product2"] SwiftStoreKit.shared.start(productIds: productIdentifiers)

Replace "com.example.app.product1" and "com.example.app.product2" with your own product identifiers.

Fetching Available Products

Before allowing users to make a purchase, it's essential to fetch the available products from the App Store. Use the following code to fetch the available products:

SwiftStoreKit.shared.retrieveProductsInfo([productIdentifier]) { result in if let product = result.retrievedProducts.first { let priceString = product.localizedPrice ?? "N/A" print("Product: \(product.localizedDescription
 

Fetching Available Products (continued)

SwiftStoreKit.shared.retrieveProductsInfo([productIdentifier]) { result in if let product = result.retrievedProducts.first { let priceString = product.localizedPrice ?? "N/A" print("Product: \(product.localizedDescription), Price: \(priceString)") } else if let invalidProductId = result.invalidProductIDs.first { print("Invalid product identifier: \(invalidProductId)") } else { print("Error: \(result.error?.localizedDescription ?? "Unknown error")") } }

Replace productIdentifier with the actual product identifier for the product you want to fetch.

Purchasing a Product







To enable users to make a purchase, you need to implement the purchase functionality. Use the following code to initiate a purchase:

SwiftStoreKit.shared.purchaseProduct(productIdentifier) { result in if case .success(let purchase) = result { print("Purchase success: \(purchase.productId)") } else if let error = result.error { print("Purchase failed: \(error.localizedDescription)") } else { print("Purchase canceled") } }

Replace productIdentifier with the actual product identifier for the product the user wants to purchase.

Handling Transactions

After a successful purchase, you need to handle the transaction. Use the following code to handle the transaction:

func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) { for transaction in transactions { switch transaction.transactionState { case .purchased: completeTransaction(transaction) case .restored: restoreTransaction(transaction) case .failed: failTransaction(transaction) case .deferred, .purchasing: // Handle deferred or purchasing state if needed break @unknown default: break } } } func completeTransaction(_ transaction: SKPaymentTransaction) { // Handle completed transaction } func restoreTransaction(_ transaction: SKPaymentTransaction) { // Handle restored transaction } func failTransaction(_ transaction: SKPaymentTransaction) { // Handle failed transaction }

Implement these methods in a class conforming to the SKPaymentTransactionObserver protocol.

Restoring Purchases

Users may need to restore their purchases on different devices or after reinstalling the app. Use the following code to implement the restore purchases functionality:

SwiftStoreKit.shared.restorePurchases { results in if results.restoreFailedPurchases.count > 0 { print("Restore failed: \(results.restoreFailedPurchases)") } else if results.restoredPurchases.count > 0 { print("Purchases restored: \(results.restoredPurchases)") } else { print("Nothing to restore") } }

Verifying Receipts

It's crucial to verify the receipts to ensure the authenticity of the purchased products. Use the following code to verify the receipts:

SwiftStoreKit.shared.verifyReceipt(using: appleValidator) { result in switch result { case .success(let receipt): print("Receipt verification success: \(receipt)") case .error(let error): print("Receipt verification failed: \(error)") } }

Replace appleValidator with your own receipt validator.

Displaying Subscription Information

If you offer subscription-based in-app purchases, you can display the subscription information to the user. Use the following code to retrieve and display the subscription information:

SwiftStoreKit.shared.retrieveSubscriptionsInfo([productIdentifier]) { result in if let product = result.retrievedProducts.first { print("Subscription info: \(product.localizedDescription)") } else if let invalidProductId = result.invalidProductIDs.first { print("Invalid product identifier: \(invalidProductId)") } else { print("Error: \(result.error?.localizedDescription ?? "Unknown error")") } }

Replace productIdentifier with the actual product identifier for the subscription.

Handling Errors

During the in-app purchase process, various errors can occur. It's essential to handle them properly to provide a smooth user experience. Use the following code to handle errors:

SwiftStoreKit.shared.shouldAddStorePaymentHandler = { payment, product in // Handle payment here return true }

Implement this code in an appropriate place in your app.

FAQs

  1. Q: How can I add multiple in-app products to my app using SwiftStoreKit?

    • A: To add multiple in-app products, you need to set up multiple product identifiers in the productIdentifiers set and initialize the StoreKit accordingly.

  2. Q: Can I implement consumable in-app purchases with SwiftStoreKit?

    • A: Yes, you can implement consumable in-app purchases by handling the transactions and updating the user's inventory or providing the desired functionality accordingly.

  3. Q: Is SwiftStoreKit compatible with both Objective-C and Swift projects?

    • A: Yes, SwiftStoreKit is compatible with both Objective-C and Swift projects. You can use it in your app regardless of the programming language.

  4. Q: How can I test in-app purchases in a sandbox environment?

    • A: To test in-app purchases in a sandbox environment, you need to configure sandbox testers in your App Store Connect account and sign in with one of the test accounts on the test device.

  5. Q: Can I customize the UI for in-app purchase dialogs using SwiftStoreKit?

    • A: Yes, you can customize the UI for in-app purchase dialogs by creating your own views and displaying them when handling the purchase process.

  6. Q: How can I handle subscription renewals and cancellations with SwiftStoreKit?

    • A: SwiftStoreKit provides methods to retrieve subscription information, allowing you to handle renewals and cancellations based on the subscription status and expiration dates.

Conclusion

In this article, we have covered the full line-by-line code for implementing in-app purchase functionality using SwiftStoreKit from GitHub in Swift. By following the provided code snippets, you can integrate in-app purchases seamlessly into your iOS application. Remember to customize the code according to your specific requirements and product identifiers. Enhance your app's revenue generation potential by offering valuable in-app purchases to your users.