I’ve had a few developers ask me how to handle stuff like virtual currency in my In-App Purchasing plugin. Out of the box it handles ‘Managed’ items like extra game levels, new swords, santa hats of health etc with ease. However ‘UnManaged’ items that can be purchased multiple times tend to be a little more specific to your game. You probably already have a virtual currency variable, like ‘coins’, somewhere in your code and you just want to increment this by say 100 when someone purchases a productid of ‘coins_100′.

Well luckily this is really simple to do. After a person purchases a productid in your game, the plugin will automatically call ‘OnPurchaseResponse’ on a script attached to the ‘UnityGameObjectReceiver’ gameobject. In the demo scene I use this fact to call ‘UpdatePurchase’ to record when a ‘Managed’ item has been purchased. This can be easily extended to handle your ‘UnManaged’ items in the following way:

public static void UpdatePurchase(PurchaseInfo purchaseInfo){
  if(purchaseInfo==null) return;
  Debug.Log("OrderID:" + purchaseInfo.orderId + " productId:" + purchaseInfo.productId + " purchaseState:" + purchaseInfo.purchaseState);
  if(purchaseInfo.purchaseState == "PURCHASED"){		//If a purchase then add to list of purchased items
    //Put any Unmanaged items here
    if(purchaseInfo.productId == "coins_100"){
      GlobalStuff.coins += 100;
    }
    //Managed Items
    if(!Instance.PurchaseInfos.Contains(purchaseInfo)){//Don't add again if this orderid already exists
      Instance.PurchaseInfos.Add(purchaseInfo);
      Save();//When you purchase an item, immediately save to file
    }
  }
}

Where ‘GlobalStuff.coins’ is your virtual currency variable, for example I tend to stick all my ‘globals’ in a ‘GameStateManager’ static class and expose them as static properties, so mine would actually be ‘GameStateManager.Coins’.

Note that you will probably want to save those precious coins for your players in between game sessions. PlayerPrefs is a good way to do this…

Hope that all makes sense. Of course this post covers the Android version of the plugin, however the iOS version is almost identical so can be amended in a similar way.

If you have an application all set up with the Android Admob Unity Plugin and you want some test ads so you can test clicking and such without upsetting Admob, here is how to do this.

First you will need your ‘Test Device ID’. The only way I know of to get this is to check the logcat in Eclipse while you device is plugged in (and running your game with Ads showing), search for a line that looks like:

To get test ads on this device, call adRequest.addTestDevice(“Your Test Device ID”);

After you have the device id, add the following method to the AdMobUnityPlugin class:

public static void SetTestMode(string test_device_id){
  AndroidJavaClass jc = new AndroidJavaClass(classname);
  jc.CallStatic("SetTestMode",test_device_id);			
}

Then this should be called before you call StartAds(), i.e.

void Start(){
  AdMobUnityPlugin.SetTestMode("My Test Device ID in here");
  AdMobUnityPlugin.StartAds();
}

That’s it, you should now get test ads. Obviously please remember to remove the call to the SetTestMode method before you deploy for real, however if you forget you can disable test mode in your application settings on the Admob website (just below where you can set the refresh rate).