I’m using StoreKit for in-app purchases. I’m finding that the API is quirky in its behavior when the user presses the “Cancel” button.
For example, if I push Cancel on the “Confirm Your In App Purchase” screen, I get a SKPaymentTransactionStateFailed transaction with error.code == SKErrorPaymentCancelled as I’d expect.
But if I push Buy and then press Cancel, I get a Failed transaction with error.code == 0. The error.localizedDescription is “Cannot connect to iTunes Store” which is clearly a lie.
It’s tempting to treat all Failed transactions as ignorable cancellations, but I can also clearly see that if the device is offline in airplane mode, I get a Failed transaction with no alert popup; I should really notify the user to explain the problem in that case.
I note that MKStoreKit assumes all failures are cancellations. MKStoreManager‘s failedTransaction method is never called; MKStoreObserver always calls transactionCanceled for all Failed transactions. The MKStoreManager.h comments recommend no error message for transactionCanceled, which makes sense, but then who will notify the user about Failed non-cancelled transactions?
What’s the best practice for handling these failures? Should I swallow errors? Always show an error, even if it’s redundant?
We have a pretty substantial user base buying stuff over mobile connections and only show alerts for
Apparently, it’s the best you can do. I’ve also seen the weird behavior on cancellation that you mention, which is a framework bug as far as I can tell.