SubscriptionMonitor

A framework for monitoring auto renewing subscriptions on iOS

SubscriptionMonitor automates the tasks required to validate in-app purchase receipts for auto-renewing subscriptions. It will periodically refresh the application receipt and validate it against your server.
An NSNotification (and optionally a closure invocation) is used to let your app know that the receipt has been refreshed and that it should check for changes in subscriptions.

Features

• Pluggable architecture allows you to define your own receipt validation class
• Support for sandbox and production receipt validation
• Support for “free” products; enable base functionality that can be overridden by paid subscriptions allowing you to enable functions in a consistent manner

Requirements

SubscriptionMonitor supports iOS 9 and above. Your project must be written in Swift 3 in order to integrate SubscriptionMonitor. An external web server is required to communicate with Apple’s servers to perform receipt validation.

Installation

SubscriptionMonitor is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod "SubscriptionMonitor"

Using SubscriptionMonitor

Using SubscriptionManager is straight-forward:

• Create an instance of a ReceiptValidator - SimpleReceiptValidator works with the sample php script (see below)

let validator = SimpleReceiptValidator(serverBase: "https://yourserver.yourdomain.com/iTunesReceiptValidator.php", 
    targetBundle:"com.yourdomain.yourapp")

• Create an instance of SubscriptionMonitor that uses the validator - this needs to held where it won’t be released, such as a property of your UIApplicationDelegate class

self.subscriptionMonitor = SubscriptionMonitor(validator: validator, 
         refreshInterval: 3600, useSandbox: false)

• You need to define the product groups and products for your auto-renewing subscriptions and add these to your SubscriptionMonitor. It is important that the product ID and product levels match those defined in iTunesConnect.
  You can also add a ‘free’ product to a product group. You won’t have a matching product in iTunesConnect for this. If a ProductGroup contains a free product, then the free product will be 'active’ when there are no other active subscriptions in that product group.

let productGroup = ProductGroup(name: "First Product Group")
let product1 = Product(productID: "com.mydomain.myProduct1", productLevel: 1, duration: .year)
let product2 = Product(productID: "com.mydomain.myProduct2", productLevel: 1, duration: .month)
let freeProduct = FreeProduct(productID: "com.mydomain.freeproduct", productLevel: 99)

productGroup.add(product: product1)
productGroup.add(product: product2)
productGroup.add(product: FreeProduct)

self.subscriptionMonitor.add(productGroup: productGroup)

• Add a closure to be executed when then the receipt and subscription data is updated:

self.subscriptionMonitor.setUpdateCallback { (receipt, subscriptions, error) -> Void in
    if error != nil {
       print("There was an error: \(error)")
    }
    //  Note that even after an error there may be active `subscriptions` if you have free products defined
    for subscription in subscriptions {
       print("Active product: \(subscription.product.productID)")
    }
}

• You can also subscribe to the SubscriptionMonitorRefreshNotification NSNotification. The userInfo for this notification may contain keys for “Error”, “Active” and “Receipt” depending on the validation result.

• Call startRefreshing to start the time-based refreshing of receipt and subscription information:

self.subscriptionMonitor.startRefreshing()

• A manual receipt validation and refresh can be triggered using refreshNow

self.subscriptionMonitor.refreshNow()

Server side script

Apple advises that you should use a server to provide an interface between your app and their receipt validation server as this allows you to build additional levels of security and trust into the process. The SimpleReceiptValidator class that is included with SubscriptionMonitor is written to work with the iTunesReceiptValidator.php script that can be found in the php directory in the repo. This script needs to be modified to contain the shared secret that can be retrieved from iTunesConnect.

Author

paulw, [email protected]

License

SubscriptionMonitor is available under the MIT license. See the LICENSE file for more info.