Merge pull request #208 from jamesmontemagno/feature/issue-190

Implement ShouldAddStorePayment

src/InAppBillingTests/InAppBillingTests.iOS/AppDelegate.cs

@@ -3,6 +3,7 @@
 using System.Linq;
 
 using Foundation;
+using StoreKit;
 using UIKit;
 
 namespace InAppBillingTests.iOS
@@ -25,7 +26,21 @@ public override bool FinishedLaunching(UIApplication app, NSDictionary options)
             global::Xamarin.Forms.Forms.Init();
             LoadApplication(new App());
 
-            return base.FinishedLaunching(app, options);
+			//initialize current one.
+			Plugin.InAppBilling.InAppBillingImplementation.OnShouldAddStorePayment = OnShouldAddStorePayment;
+			var current = Plugin.InAppBilling.CrossInAppBilling.Current;
+
+			return base.FinishedLaunching(app, options);
         }
-    }
+
+		bool OnShouldAddStorePayment(SKPaymentQueue queue, SKPayment payment, SKProduct product)
+		{
+			// true in app purchase is initiated, false cancels it.
+			// you can check if it was already purchased.
+			return true;
+		}
+
+	}
+
+
 }

src/Plugin.InAppBilling.iOS/InAppBillingImplementation.cs

@@ -23,12 +23,14 @@ public class InAppBillingImplementation : BaseInAppBilling
 		/// </summary>
 		public static Action<InAppBillingPurchase> OnPurchaseComplete { get; set; } = null;
 
+		public static Func<SKPaymentQueue, SKPayment, SKProduct, bool> OnShouldAddStorePayment { get; set; } = null;
+
 		/// <summary>
 		/// Default constructor for In App Billing on iOS
 		/// </summary>
 		public InAppBillingImplementation()
 		{
-			paymentObserver = new PaymentObserver(OnPurchaseComplete);
+			paymentObserver = new PaymentObserver(OnPurchaseComplete, OnShouldAddStorePayment);
 			SKPaymentQueue.DefaultQueue.AddTransactionObserver(paymentObserver);
 		}
 
@@ -421,10 +423,17 @@ class PaymentObserver : SKPaymentTransactionObserver
 
 		List<SKPaymentTransaction> restoredTransactions = new List<SKPaymentTransaction>();
 		private readonly Action<InAppBillingPurchase> onPurchaseSuccess;
+		private readonly Func<SKPaymentQueue, SKPayment, SKProduct, bool> onShouldAddStorePayment;
 
-		public PaymentObserver(Action<InAppBillingPurchase> onPurchaseSuccess = null)
+		public PaymentObserver(Action<InAppBillingPurchase> onPurchaseSuccess, Func<SKPaymentQueue, SKPayment, SKProduct, bool> onShouldAddStorePayment)
 		{
 			this.onPurchaseSuccess = onPurchaseSuccess;
+			this.onShouldAddStorePayment = onShouldAddStorePayment;
+		}
+
+		public override bool ShouldAddStorePayment(SKPaymentQueue queue, SKPayment payment, SKProduct product)
+		{
+			return onShouldAddStorePayment?.Invoke(queue, payment, product) ?? false;
 		}
 
 		public override void UpdatedTransactions(SKPaymentQueue queue, SKPaymentTransaction[] transactions)