Good day! I'm trying to implement notifications for auto-renew subscriptions and some parts of the whole system are not clear for me. Could you please help?
First of all, when user creates a subscription I get a receipt from user's device, verify it and create a record in database with all needed information. Now, the notifications are coming to server.
INITIAL_BUY notification - When does it come and why? I just got a receipt from device, verified it and I'm happy. Why do I need it?
Correct me if I'm wrong, this part is unclear for me, When user UPGRADES subscription level I get CANCEL notification for oldSubscription and a receipt with a new purchase for newSubscription, right? So theoretical question is - if on my server side content available in oldSubscription and content available in newSubscription are different entities than when I get CANCEL for oldSubscription I just deny user's access to oldSubscription content and when I get receipt from client I create newSubscription with access to new content, right?
DOWNGRADE and CROSSGRADE. As far as I see I get DID_CHANGE_RENEWAL_PREF or DID_CHANGE_RENEWAL_STATUS. So I will get auto_renew_status in notification for this subscription and when payed period will expire I will get a receipt from user device with info about new purchase? Or I have to figure out how to handle DOWNGRADE and CROSSGRADE only by DID_CHANGE_RENEWAL_PREF and DID_CHANGE_RENEWAL_STATUS notifications?
Thank you
The problem with server receipt validation is that there is not only one way. There are endless possibility to implement this and it depends on your use case of the usage of subscriptions and how you want the communication between your app and server to happen.
In your second paragraph is the first example of those possibilities: your server will get the receipt from the device only if you implemented it that way. Also, maybe you update your database solely based on the notifications instead of the send receipt. You see, it is all up to you ;-)
Regarding you questions:
1)
Occurs at the user’s initial purchase of the subscription.
See documentation
Theoretically this is correct, but your described use case isn't an upgrade. Would be odd, if the better subscription wouldn't contain the content of the lower one.
There isn't much to handle with down- or crossgrade. The notifications only tell you that there will be a change with the next auto-renewal. Because, the user is still eligible to access the better content until the next auto-renewal. After the better subscription expired you will receive a normal DID_RENEW with the down- or crsssgrade product id.