how to store iphone app's data even if it is uninstalled

I have an app that has some consumable items, after they are used, user can do in-app purchase to get more.

How can avoid the user to unistall the app and reinstall so he doesn't have to pay?

Can i save some data that is going to remian regardless of if he unistalls it?

Should i have the app store in a database t开发者_JS百科he udid of each device that it is installed in and when launched check that?

Thanks!

Should i have the app store in a database the udid of each device that it is installed in and when launched check that?

Something like that - you can't persist data on the device after an uninstall. So the data you want to maintain needs to be on a server (or something similar).

Possibly you have a remote store, that has a table of UUIDs and a list of all the IAPed items they've bought. When the device exec's the application, make a call to the server to see if you need to pull down the items.

You can make it better by having a bit you toggle, so on first run you make the call, on all subsequent runs you don't (you toggled the bit off). That way your not making the call every app startup.

So on that first call, you hit the server and enumerate any IAPed the client has purchased, and push them down to the phone. Happy customer!