iOS 7 Core Data and iCloud sync - core-data

Question

I am looking to integrate in my new app the option to sync core data in iCloud and so share the information on users devices. I looked around on the web but haven't found a good example or tutorial on how to do this with iOS7.
The last that I have done is to analyze the Apple receipt demo app and included in my app. It seams to work, at least at first view. Adding a record on one device and after a short while, the other device show the data - so far I was happy.
BUT, after restoring the app, the information was gone, on both devices. So i looked into the app (iExplorer) and have found the local Core Data and all my data is there. The next that I have observed is that the debugger shows this: (XXX) are of course not the real values :-)
2014-07-09 19:40:12.830 XXX[199:3507] -[PFUbiquitySwitchboardEntryMetadata setUseLocalStorage:](771): CoreData: Ubiquity: mobile~XXXXX:XXX
Using local storage: 1
2014-07-09 19:40:12.837 XXX[199:60b] asynchronously added persistent store!
2014-07-09 19:40:13.478 XXX[199:1803] -[PFUbiquitySwitchboardEntryMetadata setUseLocalStorage:](771): CoreData: Ubiquity: mobile~XXXXX:XXX
Using local storage: 0
What means first it seams like to use the local storage but than change to local storage 0.
this is the code used from Apple's demo app:
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if (persistentStoreCoordinator != nil) {
return persistentStoreCoordinator;
}
// assign the PSC to our app delegate ivar before adding the persistent store in the background
// this leverages a behavior in Core Data where you can create NSManagedObjectContext and fetch requests
// even if the PSC has no stores. Fetch requests return empty arrays until the persistent store is added
// so it's possible to bring up the UI and then fill in the results later
persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];
// prep the store path and bundle stuff here since NSBundle isn't totally thread safe
NSPersistentStoreCoordinator* psc = persistentStoreCoordinator;
NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent:#"XXX.sqlite"];
// do this asynchronously since if this is the first time this particular device is syncing with preexisting
// iCloud content it may take a long long time to download
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSFileManager *fileManager = [NSFileManager defaultManager];
NSURL *storeUrl = [NSURL fileURLWithPath:storePath];
// this needs to match the entitlements and provisioning profile
NSURL *cloudURL = [fileManager URLForUbiquityContainerIdentifier:nil];
NSString* coreDataCloudContent = [[cloudURL path] stringByAppendingPathComponent:#"XXXXX"];
cloudURL = [NSURL fileURLWithPath:coreDataCloudContent];
// The API to turn on Core Data iCloud support here.
NSDictionary* options = [NSDictionary dictionaryWithObjectsAndKeys:#"XXX", NSPersistentStoreUbiquitousContentNameKey, cloudURL, NSPersistentStoreUbiquitousContentURLKey, [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption,nil];
NSError *error = nil;
[psc lock];
if (![psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&error]) {
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
Typical reasons for an error here include:
* The persistent store is not accessible
* The schema for the persistent store is incompatible with current managed object model
Check the error message to determine what the actual problem was.
*/
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
[psc unlock];
// tell the UI on the main thread we finally added the store and then
// post a custom notification to make your views do whatever they need to such as tell their
// NSFetchedResultsController to -performFetch again now there is a real store
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(#"asynchronously added persistent store!");
[[NSNotificationCenter defaultCenter] postNotificationName:#"RefetchAllDatabaseData" object:self userInfo:nil];
});
});
return persistentStoreCoordinator;
}
Could anyone help with tutorial or solution?

Answer 1

Try these sample apps for iOS and OSX.
http://ossh.com.au/design-and-technology/software-development/sample-library-style-ios-core-data-app-with-icloud-integration/