Unity IAP with JS (InvalidCastException)

I'm trying to implement Unity IAP using JS and I get this error:
InvalidCastException: Cannot cast from source type to destination type.

The problem is this line (concretely "this"):
UnityPurchasing.Initialize(this, builder);

I use the sample Store from https://docs.unity3d.com/ScriptReference/Purchasing.Product.html
I've just added "import UnityEngine.Purchasing" that was missing:

Code (JavaScript):

1. #pragma strict
2.  
3. import UnityEngine.Purchasing;
4.  
5. public class MyStoreClass extends MonoBehaviour {
6.     static var kProductID100Currency: String = "virtualcurrency_100";
7.     var m_StoreController: IStoreController;
8.     function Start() {
9.         var builder: ConfigurationBuilder = ConfigurationBuilder.Instance(StandardPurchasingModule.Instance());
10.         builder.AddProduct(kProductID100Currency, ProductType.Consumable);
11.         UnityPurchasing.Initialize(this, builder);
12.     }
13.     public function PurchaseCurrency() {
14.         if (m_StoreController != null) {
15.             // Fetch the currency Product reference from Unity Purchasing
16.             var product: Product = m_StoreController.products.WithID(kProductID100Currency);
17.             if (product != null && product.availableToPurchase) {
18.                 m_StoreController.InitiatePurchase(product);
19.             }
20.         }
21.     }
22.     public function OnInitialized(controller: IStoreController, extensions: IExtensionProvider) {
23.         m_StoreController = controller;
24.     }
25.     public function OnInitializeFailed(error: InitializationFailureReason) {
26.     }
27.     public function ProcessPurchase(e: PurchaseEventArgs) {
28.         if (String.Equals(e.purchasedProduct.definition.id, kProductID100Currency, StringComparison.Ordinal)) {
29.             Debug.Log("Purchased 100 coins");
30.         }
31.         return PurchaseProcessingResult.Complete;
32.     }
33.     public function OnPurchaseFailed(item: Product, r: PurchaseFailureReason) {
34.     }
35. }

The C# example runs without errors. So my configuration seems to be OK.
In the C# example, MyStoreClass class derives from IStoreListener

Code (CSharp):

1.  public class Purchaser : MonoBehaviour, IStoreListener {

Could this be the problem? How I do that with JS?

 

Have you had any luck with this? I too am trying to get this to work but am stuck on the same error you're getting.

 

No, I haven't. Sorry.
Maybe you can use the Unity IAP C# script in combination with SendMenssage() from your JS scripts.

This is the reason I'm migrating to C#.....the JS script reference and support by Unity and other plugins is very poor.
I liked JS much more...it was faster to type ...

 

Your class needs to implement the IStoreListener interface:

Code (CSharp):

1. public class MyStoreClass extends MonoBehaviour implements IStoreListener {
2. ...