I would like to create a NSPersistentDocument in Mac OS X and read this document as a UIManagedDocument on iOS 7.
Is this possible?
Are both file formats compatible?
Thank you!
Interesting question - I can confirm that the basic core data files are compatible. I have a Mac app and an iOS app using the same file that gets synced using iCloud. The app is a document based app and currently I have been storing the actual database file in iCloud so the whole file gets sync'ed by iCloud.
This works fine but obviously if a user opens the file on two devices and is not careful about saving and closing there is a possibility their changes may be overridden.
Apple has approved the Mac app which uses standard NSPersistentDocument to create and save files. Unfortunately they have rejected the iOS apps with some obscure reference to not conforming to their data storage guidelines, saying that documents must be stored in /Documents directory if they need to be backed up to iCloud. Well if the user has selected iCloud then I store the files in the iCloud location provided by the API calls.
Anyway I am still waiting to hear back from them about what is specifically wrong with this approach since it seems to be the same one used by Pages and other document based apps.
If I try using UIManagedDocument then iOS creates a folder structure and stores the database inside this folder structure. The Mac app File->Open dialog then shows this folder structure as well as a file that essentially looks like a the normal sqlite file. But then perhaps OS X 10.8.4 does not implement the latest iCloud/Core Data stuff - who knows...
EDIT Here is a link to code examples and videos showing OSX and iOS app integration using Core Data and iCloud. http://ossh.com.au/design-and-technology/software-development/uimanageddocument-icloud-integration/