iOS prevent files from being backed up to iCloud - ios

Question

in my app i have to store core data database. And i have some groups and folders with default data (audiofiles, maptiles, etc) in the xcode project navigator.
I found a lot about preventing files from being backed up like:
What i have done:
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (_persistentStoreCoordinator != nil) {
return _persistentStoreCoordinator;
}
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:#"db.sqlite"];
NSLog(#"%#", storeURL.path);
NSError *error = nil;
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
//NSDictionary *options = #{NSMigratePersistentStoresAutomaticallyOption:#YES, NSInferMappingModelAutomaticallyOption:#YES};
/*NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];*/
if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
[self addSkipBackupAttributeToItemAtURL:storeURL];
return _persistentStoreCoordinator;
}
- (NSURL *)applicationDocumentsDirectory
{
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
preventing method:
- (BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)URL
{
assert([[NSFileManager defaultManager] fileExistsAtPath: [URL path]]);
NSError *error = nil;
BOOL success = [URL setResourceValue: [NSNumber numberWithBool: YES]
forKey: NSURLIsExcludedFromBackupKey error: &error];
if(!success){
NSLog(#"Error excluding %# from backup %#", [URL lastPathComponent], error);
}
return success;
}
(The minimum target iOS version is 7.0)
Is this enough? How can i check if the app now prevent backing up the core data database?
Before i added the addSkipBackupAttributeToItemAtURL method i checked the apps storage and found nothing under documents and data. I only found 3.1 MB under backups -> my iphone
- Install and launch your app
- Go to Settings > iCloud > Storage & Backup > Manage Storage
- If necessary, tap "Show all apps"
- Check your app's storage

Answer 1

You are doing it right.
Following the Apple Technical Q&A 1719: How do I prevent files from being backed up to iCloud and iTunes? you should mark with the "do not back up" attribute.
For NSURL objects, add the NSURLIsExcludedFromBackupKey attribute to prevent the corresponding file from being backed up. For CFURLRef objects, use the corresponding kCFURLIsExcludedFromBackupKey attribute.
To know which folder is more appropriated to store you Core Data database you can check the iOS Data Storage Guidelines.