A Simple and Lightweight framework for In App Purchase

by iOS Example

InAppPurchase

A Simple, Lightweight and Safe framework for In App Purchase

Feature

Installation

Carthage

github "jinSasaki/InAppPurchase"

CocoaPods

pod "InAppPurchase"

Usage

Setup Observer

NOTE: This method should be called at launch.

let iap = InAppPurchase.default
iap.addTransactionObserver(fallbackHandler: {
    // Handle the result of payment added by Store
    // See also `InAppPurchase#purchase`
})

If you want to detect the unexpected transactions, pass addTransactionObserver() with fallbackHandler.
For example, your app requested a payment, but it crashed in that process. That transaction is not finished, and then will receive at next launch.
This fallbackHandler is called when any handlers are not set to InAppPurchase via purchase(productIdentifier: handler:) method and so on.

Promoting In App Purchases is available from iOS 11. InAppPurchase supports it!

Add observer with shouldAddStorePaymentHandler.
See also SKPaymentTransactionObserver#paymentQueue(_:shouldAddStorePayment:for:)and Promoting In-App Purchases Guides

Bool in
// Return whether starting payment
}, handler: { (result) in
// Handle the result of payment added by Store
// See also `InAppPurchase#purchase`
})
“>

let iap = InAppPurchase.default
iap.set(shouldAddStorePaymentHandler: { (product) -> Bool in
    // Return whether starting payment
}, handler: { (result) in
    // Handle the result of payment added by Store
    // See also `InAppPurchase#purchase`
})

⚠️
Do not use Product#priceLocale

Only if purchase via AppStore Promoting, SKProduct#priceLocale has been not initialized. It occurs a BAD_ACCESS crash. This is a StoreKit bug. InAppPurchace resolved the crash that is occurred when received the payment, but it occurs when accessed Product#priceLocale yet. So, I recommend not to use Product#priceLocale in AppStore Promoting Payment process.

Stop payment observing if needed.

let iap = InAppPurchase.default
iap.removeTransactionObserver()

Fetch Product Information

let iap = InAppPurchase.default
iap.fetchProduct(productIdentifiers: ["PRODUCT_ID"], handler: { (result) in
    switch result {
    case .success(let products):
        // Use products
    case .failure(let error):
        // Handle `InAppPurchase.Error`
    }
})

Restore Completed Transaction

let iap = InAppPurchase.default
iap.restore(handler: { (result) in
    switch result {
    case .success(let productIds):
        // Restored with product ids
    case .failure(let error):
        // Handle `InAppPurchase.Error`
    }
})

Purchase

let iap = InAppPurchase.default
iap.purchase(productIdentifier: "PRODUCT_ID", handler: { (result) in
    // This handler is called if the payment purchased, restored, deferred or failed.

    switch result {
    case .success(let response):
        // Handle `PaymentResponse`
    case .failure(let error):
        // Handle `InAppPurchase.Error`
    }
})

For Dependency Injection

The purchase logic in the App should be safe and testable.

For example, you implemented a class to execute In-App-Purchase as follows.

// PurchaseService.swift

import Foundation
import InAppPurchase

final class PurchaseService {
    static let shared = PurchaseService()

    func purchase() {
        // Purchase with `InAppPurchase`
        InAppPurchase.default.purchase(productIdentifier: ...) {
            // Do something
        }
    }
}

It is hard to test this class because using the InAppPurchase.default in the purchase process.

This PurchaseService can be refactored to inject the dependency.
Use InAppPurchaseProvidable protocol.

// PurchaseService.swift

import Foundation
import InAppPurchase

final class PurchaseService {
    static let shared = PurchaseService()

    let iap: InAppPurchaseProvidable

    init(iap: InAppPurchaseProvidable = InAppPurchase.default) {
        self.iap = iap
    }

    func purchase() {
        // Purchase with `InAppPurchase`
        iap.purchase(productIdentifier: ...) {
            // Do something
        }
    }
}

And then you can test PurchaseService easily with InAppPurchaseStubs.framework.

// PurchaseServiceTests.swift

import XCTest
@testable import YourApp
import InAppPurchaseStubs

// Test
final class PurchaseServiceTests: XCTestCase {
    func testPurchase() {
        let expectation = self.expectation(description: "purchase handler was called.")
        let iap = StubInAppPurchase(purchaseHandler: { productIdentifier, handler in
            // Assert productIdentifier, handler, and so on.
        })
        let purchaseService = PurchaseService(iap: iap)
        purchaseService.purchase(productIdentifier: ...) {
            // Assert result
            expectation.fulfill()
        }

        wait(for: [expectation], timeout: 1)
    }
}

If you want more information for test, see also InAppPurchaseStubs and Tests.

Requirements

  • iOS 9.0+
  • Xcode 9+
  • Swift 4+

License

MIT

GitHub

https://github.com/jinSasaki/InAppPurchase