In-App Purchases

In-app purchases are essential for monetizing your application. ShipThatApp utilizes RevenueCat to simplify and manage the in-app purchase process. The boilerplate is pre-configured with RevenueCat for handling subscriptions and consumable products.

PurchaseManager

PurchaseManager.swift is central to the in-app purchase functionality. This class handles fetching product information, purchasing products, and managing transaction states.

Key Components of PurchaseManager

Properties

• productIds: A set of strings that are the identifiers for your products. These should match the product IDs set up in App Store Connect and RevenueCat.
• products: An array of Product objects that represent the products available for purchase.
• purchasedProductIDs: A set that keeps track of the product IDs that have been purchased by the user.

Functions

• loadProducts(): Calls Product.products(for:) to load the SKProduct information from the App Store.
• purchase(_ product: Product): Initiates a purchase transaction for the given Product.
• updatePurchasedProducts(): Checks the current entitlements to update purchasedProductIDs accordingly.

Transaction Observer

• observeTransactionUpdates: Observes the StoreKit transaction queue and processes updates accordingly.

RevenueCat Configuration

To configure RevenueCat, you need an API key from the RevenueCat dashboard. This key needs to be added to your Info.plist file.

Steps

1. Get the RevenueCat API Key from your RevenueCat project.

2. Add the key to your Info.plist file, for example:

   <key>RC_API_KEY</key>
   <string>Your_RevenueCat_API_Key</string>
   

3. Initialize RevenueCat in configureRevenueCat() in the app entry point (ShipThatAppApp.swift).

Handling Transactions

PurchaseManager listens for transaction updates by subscribing to Transaction.updates. Each transaction is processed to determine whether it is verified or unverified, pending, or user-cancelled.

Successful Transactions

• Upon a successful purchase, transaction.finish() is called if necessary, and updatePurchasedProducts() updates the app state to reflect the purchase's success.

Restoring Purchases

• The user can restore purchases which will sync previously completed transactions—this is also managed by the PurchaseManager.

Paywall Views

The application includes views dedicated to displaying in-app purchase options to the user.

Paywall1View

• Uses StoreKit to present pre-built ProductView components that display product information and purchase options.

Paywall2View

• Employes RevenueCat's Paywall system to show more customized purchase options.

Paywall3View

• Provides a hand-crafted view to display product information. Taps into PurchaseManager to manage purchases when users interact with the paywall.

Code Example

struct Paywall3View: View {
    @Environment(PurchaseManager.self) private var purchaseManager

    var body: some View {
        ForEach(purchaseManager.products, id: \.self) { product in
            Button(action: {
                // Initiate the purchase
                await purchaseManager.purchase(product)
            }) {
                // Custom view representing the product
                Text(product.displayName)
            }
        }
    }
}

Customizing Paywalls

Developers can create custom paywall interfaces based on the Product information fetched by the PurchaseManager. The product object includes localized pricing, description, and title, which can be used to build detailed paywalls with buttons that trigger purchases or restore operations.