android in-app billing - restoreTransactionInformation

Question

I\'m attempting to make a free app upgradable to the \"paid\" version using in-app billing. I used code from this tutorial to handle the billing as the one on the official d

Answer 1

So I finally managed to figure it out.

If you look at the Google Docs for the In App Billing Overview, it states that:

The RESTORE_TRANSACTIONS request type also triggers a PURCHASE_STATE_CHANGED broadcast intent, which contains the same type of transaction information that is sent during a purchase request, although you do not need to respond to this intent with a CONFIRM_NOTIFICATIONS message.

In a normal purchase-confirmTransaction cycle, when you request to purchase an In App Billing product, google sends back a JSON with a bunch of fields. One of these fields is 'notification_id'. When google sends a PURCHASE_STATE_CHANGED intent, it expects a CONFIRM_NOTIFICATIONS response from the app, with a bundle containing a bunch of info, including the notification_id's. All well and good here.

The problem starts when you get a PURCHASE_STATE_CHANGED from Google for a RESTORE_TRANSACTIONS request from the app. This JSON does not contain notificaion_id fields. The library still responds with a CONFIRM_NOTIFICATIONS, adding the notification_id array to the bundle, which, in this case, is null. That's what causes the NullPointerException.

Solution: I modified the BillingHelper.java class by adding a boolean to track when the user makes a normal purchase, and when he wants to restoreTransactions. If it's a restoreTransactions request, I send a message back to the handler and skip the confirmNotifications step.

EDIT: The code for the above fix is in BillingHelper.java I am using a boolean flag to track whether the user made a RESTORE_TRANSACTIONS call (isRestoreTransactions).

In BillingHelper.java's 'verifyPurchase' method, I changed the code as follows:

protected static void verifyPurchase(String signedData, String signature) {
        ArrayList purchases = BillingSecurity.verifyPurchase(signedData, signature);

        if(isRestoreTransaction)
        {
            /*
            *
            *Add some logic to retrieve the restored purchase product ID's from the 'purchases' array
            *
            */

            //Set the boolean to false
            isRestoreTranscation = false;

            //Send a message to the handler, informing it that purchases were restored
            if(mCompletedHandler != null){
                mCompletedHandler.sendEmptyMessage(0);
            } else {
                Log.e(TAG, "verifyPurchase error. Handler not instantiated. Have you called setCompletedHandler()?");
            }
        }
        else
        {
            /*
            *......
            *......
            *......
            *Original method body here
            *......
            *......
            *......
            */
        }
    }