queryPurchases() vs queryPurchaseHistoryAsync() in order to 'restore' functionality?
I'm using the Play Billing Library in order to trigger and manage purchases which in turn unlocked extra functionality within an app. This part is working.
However, what is the best way to 'restore' purchases. Say for example someone who has bought the app buys a new phone. Logs in to the Play Store, downloads my app and then finds that the payment screen to 'upgrade' is being displayed. iOS has a specific method for this but I'm not aware of one for Android.
My thoughts are to query the Play Store and confirm whether the account has previously SUCCESSFULLY purchased the item, if so then I will call the local upgrade function within the app.
It appears there are two similar methods. But which one should I used in this scenario? Where a user has either wiped their phone or bought a new one?
queryPurchases()? Or queryPurchaseHistoryAsync()?
Answer
You should use queryPurchases. That gives you all the current active (non-consumed, non-cancelled, non-expired) purchases for each SKU.
queryPurchaseHistoryAsync won't do what you need because it will only give you a list of the most recent purchases for each SKU. They may have expired, been cancelled or been consumed, and there's no way to tell. Therefore this response can't be used to tell what purchases to apply in your app.
So far as I can see, the only valid use for queryPurchaseHistoryAsync is to provide a user with a list of their purchase history. It's a bit of an oddball.
Note also: queryPurchases is synchronous so in most cases it needs to be run in some kind of background worker thread. I run mine in an AsyncTask.