Integrating Core Data and CloudKit Jared Sorge Scorebook Remember Your Games Core Data Paul Goracke – “Core Data Potpurri”, February 2014 http://bit.ly/1A5fWGr Marcus Zarra – “My Core Data Stack”, March 2015 http://bit.ly/1KQaibt TaphouseKit – GitHub Project http://bit.ly/1e4AEwo CloudKit OS X Yosemite & iOS 8 Transport layer No black magic CloudKit Used by Apple iCloud Drive & iCloud Photo Library Used by third parties 1Password CloudKit Stack CKContainer CloudKit Stack Public CKDatabase Private CKDatabase CKContainer CloudKit Stack CKRecordZone Default Zone Custom Public CKDatabase Private CKDatabase CKContainer CloudKit Stack CKRecord CKRecordZone Default Zone Custom Public CKDatabase Private CKDatabase CKContainer CloudKit Stack CKSubscription (optional) CKRecord CKRecordZone Default Zone Custom Public CKDatabase Private CKDatabase CKContainer CloudKit Stack CKSubscription (optional) CKRecord CKRecordZone Default Zone Custom Public CKDatabase Private CKDatabase CKContainer CKRecord Store data using key/value pairs NSString, NSNumber, NSData, NSDate, NSArray, CLLocation, CKAsset, CKReference Use constant strings for keys recordType property is like a database table name CKRecord Initializers initWithRecordType: initWithRecordType:zoneID: initWithRecordType:recordID: CKRecordID 2 properties recordName, zoneID Initializers initWithRecordName: initWithRecordName:zoneID: CKRecordZoneID initWithZoneName:ownerName: Use CKOwnerDefaultName for ownerName Zone name is a string Use CKRecordZoneDefaultName for the default zone CKRecordZoneID CKContainer *container = [CKContainer sharedContainer]; CKDatabase *privateDB = [container privateCloudDatabase]; CKRecordZoneID *newZone = [[CKRecordZoneID alloc] initWithZoneName:@"ScorebookData" ownerName:CKOwnerDefaultName]; [privateDB saveRecordZone:newZone completionHandler:^(CDRecordZone *zone, NSError *error) { //Error handling //Additional configuration }]; CKRecord Creation CKRecordZoneID *zone = // CKRecordID *recordID = [[CKRecordID alloc] initWithRecordName:self.ckRecordName zoneID:zone]; CKRecord *gameRecord = [[CKRecord alloc] initWithRecordType:[SBGame entityName] recordID:recordID]; [gameRecord setObject:self.title forKey SBGameTitleKEY]; gameRecord[SBGameScoringTypeKEY] = @(self.scoringType); gameRecord[SBGamePointsToWinKEY] = @(self.pointsToWin); CKAsset Blob storage Single initializer initWithFileURL: No support for NSData Attach to CKRecord instance as a value CKAsset NSURL *fileURL = // … url of path to file CKAsset *asset = [[CKAsset alloc] initWithFileURL:fileURL]; CKRecord *record = // record[@“asset”] = asset; CKReference Relate records with separate record types Relationships in a single zone only 1:many relationships many:many not officially supported Associate on the many side of the relationship Person Player CKReference Initializers -initWithRecordID:action: -initWithRecord:action: Set the delete action on the initializer CKReferenceActionDeleteSelf CKReferenceActionNone CKReference CKRecordID *personRecordID = // CKReference *personReference = [[CKReference alloc] initWithRecordID:personRecordID action:CKReferenceActionDeleteSelf]; CKRecord *playerRecord = // playerRecord[SBPlayerPersonKEY] = personReference; CKSubscription Subscribes to changes of a record type or custom zone Can use a search predicate to determine matches Uses push notifications to alert you of changes Uses the remote notification system in iOS CKSubscription Save to the database for activation on a device Save once, then retrieve on other devices CKSubscription CKRecordZoneID *userRecordZone = // [privateDB fetchAllSubscriptionsWithCompletionHandler:^(NSArray *subs, NSError *error) { CKSubscription *subscription = [subs firstObject]; if (subscription == nil) { subscription =[[CKSubscription alloc] initWithZoneID:userRecordZone options:0]; } [privateDB saveSubscription:scorebookDataSubscription completionHandler:^(CKSubscription *sub, NSError *error) { //handle error }]; }]; CloudKit Stack CKSubscription (optional) CKRecord CKRecordZone Default Zone Custom Public CKDatabase Private CKDatabase CKContainer Putting it together Sync is about upload, download, and conflict handling Make a Plan Database: public, private, or both? Using a custom record zone? Are you happy with your Core Data object graph? How to make specific things generic, and generic things specific? SBCloudKitCompatible @protocol SBCloudKitCompatible <NSObject> //Add to entities @property (nonatomic, strong) NSString *ckRecordName; @property (nonatomic, strong) NSDate *modificationDate; //Add to categories on the model objects - (CKRecord *)cloudKitRecordInRecordZone:(CKRecordZoneID *)zone; + (NSManagedObject *)managedObjectFromRecord:(CKRecord *)record context:(NSManagedObjectContext *)context; @end ckRecordName - (void)awakeFromInsert { [super awakeFromInsert]; NSString *uuid = [[NSUUID UUID] UUIDString]; NSString *recordName = [NSString stringWithFormat: @“SBGame|~|%@“, uuid]; /* SBGame|~|386c1919-5f25-4be2-975f-5b34506c51db */ self.ckRecordName = recordName; } modificationDate - (void)processCoreDataWillSaveNotification:(NSNotification *)notification { NSManagedObjectContext *context = // monitored context NSSet *inserted = [context insertedObjects]; NSSet *updated = [context updatedObjects]; if (inserted.count == 0 && updated.count == 0) { return; } for (id<SBCloudKitCompatible> managedObject in inserted) { managedObject.modificationDate = [NSDate date]; } for (id<SBCloudKitCompatible> managedObject in updated) { managedObject.modificationDate = [NSDate date]; } } modificationDate - (void)processCoreDataWillSaveNotification:(NSNotification *)notification { NSManagedObjectContext *context = // monitored context NSSet *inserted = [context insertedObjects]; NSSet *updated = [context updatedObjects]; if (inserted.count == 0 && updated.count == 0) { return; } for (id<SBCloudKitCompatible> managedObject in inserted) { managedObject.modificationDate = [NSDate date]; } for (id<SBCloudKitCompatible> managedObject in updated) { managedObject.modificationDate = [NSDate date]; } } cloudKitRecordInRecordZone: - (CKRecord *)cloudKitRecordInRecordZone:(CKRecordZoneID *)zone { CKRecordID *recordID = [[CKRecordID alloc] initWithRecordName:self.ckRecordName zoneID:zone]; NSString *entityName = [SBPerson entityName]; CKRecord *personRecord = [[CKRecord alloc] initWithRecordType:entityName recordID:recordID]; personRecord[SBPersonFirstNameKEY] = self.firstName; personRecord[SBPersonLastNameKEY] = self.lastName; personRecord[SBPersonEmailAddressKEY] = self.emailAddress; if (self.imageURL) { CKAsset *imageAsset = [[CKAsset alloc] initWithFileURL:[self urlForImage]]; personRecord[SBPersonAvatarKEY] = imageAsset; } return personRecord; } managedObjectFromRecord:context: + (instancetype)managedObjectFromRecord:(CKRecord *)ckRecord context:(NSManagedObjectContext *)context { CKRecordID *recordID = ckRecord.recordID; SBMatch *match = [SBMatch matchWithCloudKitRecordName:recordID.recordName managedObjectContext:context]; if (match.modificationDate != nil && ckRecord.modificationDate < match.modificationDate) { return match; } match.date = ckRecord[SBMatchDateKEY]; match.monthYear = ckRecord[SBMatchMonthYearKEY]; match.finished = [ckRecord[SBMatchFinishedKEY] boolValue]; match.note = [ckRecord objectForKey:SBMatchNoteKEY]; … managedObjectFromRecord:context: … CKReference *gameRef = ckRecord[SBMatchGameKEY]; if (gameRef != nil) { SBGame *game = [SBGame gameWithCloudKitRecordID:gameRef.recordID managedObjectContext:context]; match.game = game; } return match; } Upload to CloudKit Monitor NSManagedObjectContextDidSaveNotification on the main thread NSManagedObjectContext Gather the objects from the userInfo dictionary in the posted notification Convert the inserted/updated objects into an array of CKRecords Convert to CKRecord CKRecordZoneID *zone = // NSMutableArray *savedRecords = [NSMutableArray array]; for (id<SBCloudKitCompatible> object in insertedObjects) { CKRecord *record = [object cloudKitRecordInRecordZone:zone]; [savedRecords addObject:record]; } Upload to CloudKit Monitor NSManagedObjectContextDidSaveNotification on the main thread NSManagedObjectContext Gather the objects from the userInfo dictionary in the posted notification Convert the inserted/updated objects into an array of CKRecords Convert the deleted objects into an array of CKRecordIDs Convert to CKRecordID CKRecordZoneID *zone = // NSMutableArray *deletedRecords = [NSMutableArray array]; for (id<SBCloudKitCompatible> managedObject in deletedObjects) { CKRecordID *deletedRecordID = [[CKRecordID alloc] initWithRecordName:managedObject.ckRecordName zoneID:zone]; [deletedRecords addObject:deletedRecordID]; } } Upload to CloudKit Monitor NSManagedObjectContextDidSaveNotification on the main thread NSManagedObjectContext Gather the objects from the userInfo dictionary in the posted notification Convert the inserted/updated objects into an array of CKRecords Convert the deleted objects into an array of CKRecordIDs Use a CKModifyRecordsOperation to send the arrays to CloudKit Upload to CloudKit CKDatabase *database = // CKModifyRecordsOperation *modifyRecords = [[CKModifyRecordsOperation alloc] initWithRecordsToSave:savedRecords recordIDsToDelete:deletedRecords]; //Called only on the saved records array modifyRecords.perRecordCompletionBlock = ^(CKRecord *record, NSError *error) { //Handle Error }; modifyRecords.modifyRecordsCompletionBlock = ^(NSArray *saved, NSArray *deleted, NSError *error) { //Handle error, perform cleanup }; modifyRecords.savePolicy = CKRecordSaveAllKeys; [database addOperation:modifyRecords];