From ccb77dcd1bb789c0006e7c78e47022e7515d3960 Mon Sep 17 00:00:00 2001
From: James Montemagno <james.montemagno@gmail.com>
Date: Wed, 23 Jan 2019 19:40:56 -0800
Subject: [PATCH] Implement ShouldAddStorePayment

---
 .../InAppBillingTests.iOS/AppDelegate.cs      | 19 +++++++++++++++++--
 .../InAppBillingImplementation.cs             | 13 +++++++++++--
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/InAppBillingTests/InAppBillingTests.iOS/AppDelegate.cs b/src/InAppBillingTests/InAppBillingTests.iOS/AppDelegate.cs
index 155e2e9..52e811c 100644
--- a/src/InAppBillingTests/InAppBillingTests.iOS/AppDelegate.cs
+++ b/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;
+		}
+
+	}
+
+
 }
diff --git a/src/Plugin.InAppBilling.iOS/InAppBillingImplementation.cs b/src/Plugin.InAppBilling.iOS/InAppBillingImplementation.cs
index 7a89906..3a5c858 100644
--- a/src/Plugin.InAppBilling.iOS/InAppBillingImplementation.cs
+++ b/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)