Hacknocraft / SwiftyStoreKit

Lightweight In App Purchases Swift framework for iOS 8.0+, tvOS 9.0+ and macOS 10.10+

SwiftyStoreKit is a lightweight In App Purchases framework for iOS 8.0+, tvOS 9.0+ and macOS 10.10+.

Language	Branch	Pod version	Xcode version
Swift 3.0	master	>= 0.5.x	Xcode 8 or greater
Swift 2.3	swift-2.3	0.4.x	Xcode 8, Xcode 7.3.x
Swift 2.2	swift-2.2	0.3.x	Xcode 7.3.x

Preview

Setup + Complete Transactions

Apple recommends to register a transaction observer as soon as the app starts:

Adding your app's observer at launch ensures that it will persist during all launches of your app, thus allowing your app to receive all the payment queue notifications.

SwiftyStoreKit supports this by calling completeTransactions() when the app starts:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

	SwiftyStoreKit.completeTransactions() { completedTransactions in
	
	    for completedTransaction in completedTransactions {
	
	        if completedTransaction.transactionState == .purchased || completedTransaction.transactionState == .restored {
	
	            print("purchased: \(completedTransaction.productId)")
	        }
	    }
	}
  return true
}

If there are any pending transactions at this point, these will be reported by the completion block so that the app state and UI can be updated.

Retrieve products info

SwiftyStoreKit.retrieveProductsInfo(["com.musevisions.SwiftyStoreKit.Purchase1"]) { result in
    if let product = result.retrievedProducts.first {
        let priceString = product.localizedPrice!
        print("Product: \(product.localizedDescription), price: \(priceString)")
    }
    else if let invalidProductId = result.invalidProductIDs.first {
        return alertWithTitle("Could not retrieve product info", message: "Invalid product identifier: \(invalidProductId)")
    }
    else {
	     print("Error: \(result.error)")
    }
}

Purchase a product

SwiftyStoreKit.purchaseProduct("com.musevisions.SwiftyStoreKit.Purchase1") { result in
    switch result {
    case .success(let productId):
        print("Purchase Success: \(productId)")
    case .error(let error):
        print("Purchase Failed: \(error)")
    }
}

Restore previous purchases

SwiftyStoreKit.restorePurchases() { results in
    if results.restoreFailedProducts.count > 0 {
        print("Restore Failed: \(results.restoreFailedProducts)")
    }
    else if results.restoredProductIds.count > 0 {
        print("Restore Success: \(results.restoredProductIds)")
    }
    else {
        print("Nothing to Restore")
    }
}

Retrieve local receipt

let receiptData = SwiftyStoreKit.localReceiptData
let receiptString = receiptData.base64EncodedString
// do your receipt validation here

Verify Receipt

SwiftyStoreKit.verifyReceipt(password: "your-shared-secret") { result in
    if case .error(let error) = result {
        if case .noReceiptData = error {
            self.refreshReceipt()
        }
    }
}

func refreshReceipt() {
    SwiftyStoreKit.refreshReceipt { result in
        switch result {
        case .success(let receiptData):
            print("Receipt refresh success: \(receiptData.base64EncodedString)")
        case .error(let error):
            print("Receipt refresh failed: \(error)")
        }
    }
}

Verify Purchase

SwiftyStoreKit.verifyReceipt(password: "your-shared-secret") { result in
    switch result {
    case .success(let receipt):
        // Verify the purchase of Consumable or NonConsumable
        let purchaseResult = SwiftyStoreKit.verifyPurchase(
            productId: "com.musevisions.SwiftyStoreKit.Purchase1",
            inReceipt: receipt
        )
        switch purchaseResult {
        case .purchased(let expiresDate):
            print("Product is purchased.")
        case .notPurchased:
            print("The user has never purchased this product")
        }
    case .Error(let error):
        print("Receipt verification failed: \(error)")
    }
}

Note that for consumable products, the receipt will only include the information for a couples of minutes after the purchase.

Verify Subscription

SwiftyStoreKit.verifyReceipt(password: "your-shared-secret") { result in
    switch result {
    case .success(let receipt):
        // Verify the purchase of a Subscription
        let purchaseResult = SwiftyStoreKit.verifySubscription(
            productId: "com.musevisions.SwiftyStoreKit.Subscription",
            inReceipt: receipt,
            validUntil: NSDate(),
            validDuration: 3600 * 24 * 30 // Non Renewing Subscription only
        )
        switch purchaseResult {
        case .purchased(let expiresDate):
            print("Product is valid until \(expiresDate)")
        case .expired(let expiresDate):
            print("Product is expired since \(expiresDate)")
        case .notPurchased:
            print("The user has never purchased this product")
        }

    case .error(let error):
        print("Receipt verification failed: \(error)")
    }
}

To test the expiration of a Non Renewing Subscription, you must indicate the validDuration time interval in seconds.

NOTE: The framework provides a simple block based API with robust error handling on top of the existing StoreKit framework. It does NOT persist in app purchases data locally. It is up to clients to do this with a storage solution of choice (i.e. NSUserDefaults, CoreData, Keychain).

Installation

CocoaPods

SwiftyStoreKit can be installed as a CocoaPod and builds as a Swift framework. To install, include this in your Podfile.

use_frameworks!

pod 'SwiftyStoreKit'

Once installed, just import SwiftyStoreKit in your classes and you're good to go.

Carthage

To integrate SwiftyStoreKit into your Xcode project using Carthage, specify it in your Cartfile:

github "bizz84/SwiftyStoreKit"

NOTE: Please ensure that you have the latest Carthage installed.

Swift 2.2 / 2.3 / 3.0

Language	Branch	Pod version	Xcode version
Swift 3.0	master	>= 0.5.x	Xcode 8 or greater
Swift 2.3	swift-2.3	0.4.x	Xcode 8, Xcode 7.3.x
Swift 2.2	swift-2.2	0.3.x	Xcode 7.3.x

Change Log

See the Releases Page

Sample Code

The project includes demo apps for iOS and macOS showing how to use SwiftyStoreKit. Note that the pre-registered in app purchases in the demo apps are for illustration purposes only and may not work as iTunes Connect may invalidate them.

Features

• Super easy to use block based API
• Support for consumable, non-consumable in-app purchases
• Support for free, auto renewable and non renewing subscriptions
• Receipt verification
• iOS, tvOS and macOS compatible
• enum-based error handling

Known issues

Requests lifecycle

While SwiftyStoreKit tries handle concurrent purchase or restore purchases requests, it is not guaranteed that this will always work flawlessly. This is in part because using a closure-based API does not map perfectly well with the lifecycle of payments in SKPaymentQueue.

In real applications the following could happen:

1. User starts a purchase
2. User kills the app
3. OS continues processing this, resulting in a failed or successful purchase
4. App is restarted (payment queue is not updated yet)
5. User starts another purchase (the old transaction may interfere with the new purchase)

To prevent situations like this from happening, a completeTransactions() method has been added in version 0.2.8. This should be called when the app starts as it can take care of clearing the payment queue and notifying the app of the transactions that have finished.

Multiple accounts

The user can background the hosting application and change the Apple ID used with the App Store, then foreground the app. This has been observed to cause problems with SwiftyStoreKit - other IAP implementations may suffer from this as well.

Essential Reading

• Apple - WWDC16, Session 702: Using Store Kit for In-app Purchases with Swift 3
• Apple - TN2387: In-App Purchase Best Practices
• Apple - About Receipt Validation
• Apple - Receipt Validation Programming Guide
• Apple - Validating Receipts Locally
• Apple - Offering Subscriptions
• objc.io - Receipt Validation

Implementation Details

In order to make a purchase, two operations are needed:

• Obtain the SKProduct corresponding to the productId that identifies the app purchase, via SKProductRequest.

• Submit the payment for that product via SKPaymentQueue.

The framework takes care of caching SKProducts so that future requests for the same SKProduct don't need to perform a new SKProductRequest.

Requesting products information

SwiftyStoreKit wraps the delegate-based SKProductRequest API with a block based class named InAppProductQueryRequest, which returns a RetrieveResults value with information about the obtained products:

public struct RetrieveResults {
    public let retrievedProducts: Set<SKProduct>
    public let invalidProductIDs: Set<String>
    public let error: NSError?
}

This value is then surfaced back to the caller of the retrieveProductsInfo() method the completion closure so that the client can update accordingly.

Purchasing a product / Restoring purchases

InAppProductPurchaseRequest is a wrapper class for SKPaymentQueue that can be used to purchase a product or restore purchases.

The class conforms to the SKPaymentTransactionObserver protocol in order to receive transactions notifications from the payment queue. The following outcomes are defined for a purchase/restore action:

enum TransactionResult {
    case purchased(productId: String)
    case restored(productId: String)
    case failed(error: NSError)
}

Depending on the operation, the completion closure for InAppProductPurchaseRequest is then mapped to either a PurchaseResult or a RestoreResults value and returned to the caller.

Credits

Many thanks to phimage for adding macOS support and receipt verification.

Apps using SwiftyStoreKit

It would be great to showcase apps using SwiftyStoreKit here. Pull requests welcome :)

• MDacne - Acne analysis and treatment
• Pixel Picker - Image Color Picker
• KType - Space shooter game
• iPic - Automatically upload images and save Markdown links
• iHosts - Perfect for editing /etc/hosts
• Arise - Calorie counter
• Truth Truth Lie - iMessage game, featured by Apple

License

Copyright (c) 2015-2016 Andrea Bizzotto [e-mail]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.