How to properly restore an in-app purchase?

Question

Some of my users are complaining that the in-app "premium version" that they bought is not getting restored.

I contacted one of these users and I sent an APK with additional messages. This is what happens:

1. When the user tries to buy the item again, it receives the message Unable to buy item (response: 7: Item already owned). This is the expected message, as he already bought it.
2. But when the user tries to restore the purchases with the same SKU, it returns null/false.

This is the callback from the purchase:

@Override
public void onIabPurchaseFinished(IabResult result, Purchase purchase) {
    if (result.isFailure()) {
        Log.d("debug", "failed - " + result.mMessage);
        return;
    }

    Log.d("debug", "success");

    // continue with the purchase validation...
}

This is the callback from restore purchases:

@Override
public void onQueryInventoryFinished(IabResult result, Inventory inventory) {
    if (result.isFailure()) { 
        Log.d("debug", "inventory: failed (" + result.mMessage + ")");
        return;
    }

    if (inventory.hasPurchase(SKU_PREMIUM)) {
        Log.d("debug", "success - purchase restored");
    }
    else {
        Log.d("debug", "failure - no purchase found for this user");
    }
}

Please note that this is happening with only a few users, I tested several times and on my tests I receive the success - purchase restored message after querying the inventory.

Just to be clear, I'm using v3 API and this SKU is a managed item. I need to check if the user already bought it or not (I don't want to consume it).

Answer 1

Unfortunately this was my mistake.

The affected users bought the in-app product on a very old version, which had different developer payloads for the same SKU, depending on where in the application the purchase was done.

These different developer payloads were removed from the latest versions and it obviously broke the previous purchases.

Answer 2

If you are using v3 version of in app purchase then The Version 3 API supports managed in-app products and subscriptions.

Managed in-app products are items that have their ownership information tracked and managed by Google Play. When a user purchases a managed in-app item, Google Play stores the purchase information for each item on a per-user basis. This enables you to later query Google Play at any time to restore the state of the items a specific user has purchased. This information is persistent on the Google Play servers even if the user uninstalls the application or if they change devices.

If you are using the Version 3 API, you can also consume managed items within your application. You would typically implement consumption for items that can be purchased multiple times (such as in-game currency, fuel, or magic spells). Once purchased, a managed item cannot be purchased again until you consume the item, by sending a consumption request to Google Play.

To consume item refer below method:

IabHelper.OnIabPurchaseFinishedListener mPurchaseFinishedListener = new IabHelper.OnIabPurchaseFinishedListener() {
        public void onIabPurchaseFinished(IabResult result, Purchase purchase) {
            Log.d(TAG, "Purchase finished: " + result + ", purchase: " + purchase);

            // if we were disposed of in the meantime, quit.
            if (mHelper == null) return;

            if (result.isFailure()) {
                complain("Error purchasing: " + result);
                return;
            }
            if (!verifyDeveloperPayload(purchase)) {
                complain("Error purchasing. Authenticity verification failed.");
                return;
            }
            Log.d(TAG, "Purchase successful.");

            if (purchase.getSku().equals(SKU_PREMIUM)) {
                //consumeItem();
                Constant.showProgressDialog(getActivity());
                mHelper.consumeAsync(purchase, mConsumeFinishedListener);
            }


        }
    };

Also add this method to your activity

IabHelper.OnConsumeFinishedListener mConsumeFinishedListener = new IabHelper.OnConsumeFinishedListener() {
        public void onConsumeFinished(Purchase purchase, IabResult result) {
            Log.d(TAG, "Consumption finished. Purchase: " + purchase + ", result: " + result);

            // if we were disposed of in the meantime, quit.
            if (mHelper == null) return;

            // We know this is the "gas" sku because it's the only one we consume,
            // so we don't check which sku was consumed. If you have more than one
            // sku, you probably should check...
            if (result.isSuccess()) {
                // successfully consumed, so we apply the effects of the item in our
                // game world's logic, which in our case means filling the gas tank a bit
                Log.d(TAG, "Consumption successful. Provisioning.");

            }
            else {
                complain("Error while consuming: " + result);
            }

            Log.d(TAG, "End consumption flow.");
        }
    };

In your IabHelper.java class have below method:

int queryPurchases(Inventory inv, String itemType) throws JSONException, RemoteException {
        // Query purchases
        logDebug("Querying owned items, item type: " + itemType);
        logDebug("Package name: " + mContext.getPackageName());
        boolean verificationFailed = false;
        String continueToken = null;

        do {
            logDebug("Calling getPurchases with continuation token: " + continueToken);
            Bundle ownedItems = mService.getPurchases(3, mContext.getPackageName(),
                    itemType, continueToken);

            int response = getResponseCodeFromBundle(ownedItems);
            logDebug("Owned items response: " + String.valueOf(response));
            if (response != BILLING_RESPONSE_RESULT_OK) {
                logDebug("getPurchases() failed: " + getResponseDesc(response));
                return response;
            }
            if (!ownedItems.containsKey(RESPONSE_INAPP_ITEM_LIST)
                    || !ownedItems.containsKey(RESPONSE_INAPP_PURCHASE_DATA_LIST)
                    || !ownedItems.containsKey(RESPONSE_INAPP_SIGNATURE_LIST)) {
                logError("Bundle returned from getPurchases() doesn't contain required fields.");
                return IABHELPER_BAD_RESPONSE;
            }

            ArrayList<String> ownedSkus = ownedItems.getStringArrayList(
                        RESPONSE_INAPP_ITEM_LIST);
            ArrayList<String> purchaseDataList = ownedItems.getStringArrayList(
                        RESPONSE_INAPP_PURCHASE_DATA_LIST);
            ArrayList<String> signatureList = ownedItems.getStringArrayList(
                        RESPONSE_INAPP_SIGNATURE_LIST);

            for (int i = 0; i < purchaseDataList.size(); ++i) {
                String purchaseData = purchaseDataList.get(i);
                String signature = signatureList.get(i);
                String sku = ownedSkus.get(i);
                if (Security.verifyPurchase(mSignatureBase64, purchaseData, signature)) {
                    logDebug("Sku is owned: " + sku);
                    Purchase purchase = new Purchase(itemType, purchaseData, signature);

                    if (TextUtils.isEmpty(purchase.getToken())) {
                        logWarn("BUG: empty/null token!");
                        logDebug("Purchase data: " + purchaseData);
                    }

                    // Record ownership and token
                    inv.addPurchase(purchase);
                }
                else {
                    logWarn("Purchase signature verification **FAILED**. Not adding item.");
                    logDebug("   Purchase data: " + purchaseData);
                    logDebug("   Signature: " + signature);
                    verificationFailed = true;
                }
            }

            continueToken = ownedItems.getString(INAPP_CONTINUATION_TOKEN);
            logDebug("Continuation token: " + continueToken);
        } while (!TextUtils.isEmpty(continueToken));

        return verificationFailed ? IABHELPER_VERIFICATION_FAILED : BILLING_RESPONSE_RESULT_OK;
    }

In This you will get the owned item list