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I submitted my first iPad app to apple a few days ago. In the meantime the iPhone version of it is almost ready. I would like to use iCloud to synchronize the core data model between both apps. Is it possible to do this? As I wrote, these are two different applications (not a universal app) that use a core data store with the same structure: names, entities and attributes are the same. Is it possible to do this? Do I have to change anything in the core data model? I was thinking that if I have to do radical changes to it, it would be more convenient to remove the binary from iTunes Connect before it gets reviewed instead of having to do difficult migration changes afterwards. Any tips?

strave
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1 Answers1

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iCloud's support for Core Data is supposed to be virtually automatic. You do have to do some extra work though to set up syncing and to respond to changes as they occur via the cloud (refresh UI etc). You shouldn't have to change your model as long as you haven't used the new ordered relationships introduced in iOS5 (not supported via iCloud).

Other things to think about are the amount of data you are planning to store and whether you are seeding Core Data with an initial data set on each device.

Having said all that, Core Data via iCloud is new technology and there are still some issues to be ironed out by the early adopters. There is no sample code from Apple yet or many guidelines on best practice. If I were you I would hang back from doing this straight away.

Take a look at the Core Data/iCloud release notes.

Robin Summerhill
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  • Thank you very much for such detailed answer. Why is it important to think about the amount of data I'm planning to store? Could it become too slow? I don't want to have an initial data set on each device. Everything should be user defined data. Does this change things? – strave Oct 24 '11 at 18:30
  • Look at [how to be a responsible iCloud app](http://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/iCloud/iCloud.html#//apple_ref/doc/uid/TP40007072-CH5-SW5). – Robin Summerhill Oct 24 '11 at 18:38
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    Things are never as easy as they look. Look at the devforums threads to see all the problems developers have been having with iCloud and Core Data: https://devforums.apple.com/message/588783 – Z S Dec 06 '11 at 14:28