CloudKit - Just another iCloud API?

This is a talk about the structure and my first steps with CloudKit. It shows how you could start learning CloudKit and lists a number of pitfalls I ran into, when I started my first project.

Transcript

1. CloudKit
   Just another iCloud API?
   Michael Ochs
   

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2. What is CloudKit?
   

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3. What is CloudKit?
   “The CloudKit framework provides interfaces for moving data between
   your app and your iCloud containers”
   - CloudKit Framework Reference
   

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4. What is CloudKit?
   “CloudKit is not a replacement for your app’s existing data objects.
   Instead, CloudKit provides complementary services for managing the
   transfer of data to and from iCloud servers.”
   - CloudKit Framework Reference
   

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5. What is CloudKit?
   • it is a transfer api to move data to and from the cloud
   • it behaves like a remote database in many parts
   • but: It is not your app’s database
   

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6. Structure
   

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7. Structure
   • local api
   • remote database
   • remote dashboard
   • records
   • references
   • containers
   • queries
   • operations
   • zones
   • subscriptions
   

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8. Structure
   Data
   Container
   Public Database
   Private
   Database
   Private
   Database
   Private
   Database
   Private
   Database
   Private
   Database
   Private
   Database
   Private
   Database
   Private
   Database
   Private
   Database
   Bulk Storage
   Zone
   Record
   Record
   Record
   Asset
   Asset
   Asset
   

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9. Structure
   Convenience API
   CKContainer CKDatabase
   CKRecord
   

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10. Structure
    Convenience API
    CKContainer CKDatabase
    CKRecord
    CKQuery
    

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11. Structure
    Convenience API
    CKContainer CKDatabase CKSubscription
    

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12. Structure
    Not so convenient API
    CKContainer CKDatabase
    CKRecord
    CKModifyRecordsOperation
    CKRecord
    CKQueryOperation
    CKQuery
    CKRecord
    CKModifySubscriptionsOperation
    CKSubscription
    

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13. Structure
    Inconvenient API
    CKModifyRecordsOperation
    CKQueryOperation
    CKModifySubscriptionsOperation CKModifyRecordZonesOperation
    CKFetchSubscriptionsOperation CKFetchRecordZonesOperation
    CKFetchRecordsOperation
    CKFetchRecordChangesOperation
    CKDiscoverAllContactsOperation
    CKDiscoverUserInfosOperation
    CKFetchNotificationChangesOperation
    CKMarkNotificationsReadOperation
    CKModifyBadgeOperation
    

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14. CKModifyRecordsOperation
    CKQueryOperation
    CKModifySubscriptionsOperation CKModifyRecordZonesOperation
    CKFetchSubscriptionsOperation CKFetchRecordZonesOperation
    CKFetchRecordsOperation
    CKFetchRecordChangesOperation
    CKDiscoverAllContactsOperation
    CKDiscoverUserInfosOperation
    CKFetchNotificationChangesOperation
    CKMarkNotificationsReadOperation
    CKModifyBadgeOperation
    Structure
    InternalError
    PartialFailure
    NetworkUnavailable
    NetworkFailure
    BadContainer
    ServiceUnavailable
    RequestRateLimited
    MissingEntitlement
    NotAuthenticated
    PermissionFailure
    UnknownItem
    InvalidArguments
    ResultsTruncated
    ServerRecordChanged
    ServerRejectedRequest
    AssetFileNotFound
    AssetFileModified
    IncompatibleVersion
    ConstraintViolation
    OperationCancelled
    ChangeTokenExpired
    BatchRequestFailed
    ZoneBusy
    BadDatabase
    QuotaExceeded
    ZoneNotFound
    

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15. CKModifyRecordsOperation
    CKQueryOperation
    CKModifySubscriptionsOperation CKModifyRecordZonesOperation
    CKFetchSubscriptionsOperation CKFetchRecordZonesOperation
    CKFetchRecordsOperation
    CKFetchRecordChangesOperation
    CKDiscoverAllContactsOperation
    CKDiscoverUserInfosOperation
    CKFetchNotificationChangesOperation
    CKMarkNotificationsReadOperation
    CKModifyBadgeOperation
    Structure
    Do not start with CloudKit in your productive application!
    

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16. Structure
    • This api has nothing to do with convenience
    • …but this api is great
    • It gives you a lot of responsibility
    • …but also a lot of power and flexibility
    

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17. Dashboard
    

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18. Dashboard
    • Web based administration
    • View, create, edit, and remove records
    • Edit, and remove record layouts
    • Edit access groups / privileges
    

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21. Demo
    

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22. CKDatabase
    

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23. CKDatabase
    • Public database
    • readable by everyone
    • writable by every iCloud user
    • Private database
    • readable and writable by the current iCloud user
    

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24. CKDatabase
    CKContainer *container = [CKContainer defaultContainer];

    CKDatabase *database = [container publicCloudDatabase];
    Public Database
    

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25. CKDatabase
    CKContainer *container = [CKContainer defaultContainer];

    CKDatabase *database = [container publicCloudDatabase];
    Public Database
    

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26. CKDatabase
    CKContainer *container = [CKContainer defaultContainer];

    CKDatabase *database = [container publicCloudDatabase];
    Public Database
    

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27. CKDatabase
    CKContainer *container = [CKContainer defaultContainer];

    CKDatabase *database = [container privateCloudDatabase];
    Private Database
    

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28. CKDatabase
    CKContainer *container = [CKContainer defaultContainer];

    CKDatabase *database = [container privateCloudDatabase];
    Private Database
    

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29. CKDatabase
    CKRecordID *recordID = …;

    [database deleteRecordWithID:recordID

    completionHandler:^(CKRecordID *recordID, NSError *error) {

    if (error) {

    dispatch_async(dispatch_get_main_queue(), ^{

    [self presentError:error

    completionHandler:^(BOOL didRecover){

    // TODO: handle error

    }];

    });

    return;

    }

    

    // TODO: handle success

    }];
    

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30. CKDatabase
    CKRecordID *recordID = …;

    [database deleteRecordWithID:recordID

    completionHandler:^(CKRecordID *recordID, NSError *error) {

    if (error) {

    dispatch_async(dispatch_get_main_queue(), ^{

    [self presentError:error

    completionHandler:^(BOOL didRecover){

    // TODO: handle error

    }];

    });

    return;

    }

    

    // TODO: handle success

    }];
    

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31. CKDatabase
    CKRecordID *recordID = …;

    [database deleteRecordWithID:recordID

    completionHandler:^(CKRecordID *recordID, NSError *error) {

    if (error) {

    dispatch_async(dispatch_get_main_queue(), ^{

    [self presentError:error

    completionHandler:^(BOOL didRecover){

    // TODO: handle error

    }];

    });

    return;

    }

    

    // TODO: handle success

    }];
    

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32. CKRecord
    

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33. CKRecord
    • Data object
    • Dictionary like api
    • On the fly model generation
    

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34. CKRecord
    Each record has a…
    • …record type
    • …record id
    • …creation date / user record id
    • …modification date / user record id
    

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35. CKRecord
    Class
    record type
    record id
    creation date / user record id
    modification date / user record id
    Type
    NSString*
    CKRecordID*
    NSDate* / CKRecordID*
    NSDate* / CKRecordID*
    

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36. CKRecord
    CloudKit
    record type
    record id
    creation date / user record id
    modification date / user record id
    CoreData
    entity name
    object id
    n/a
    n/a
    

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37. CKRecord
    CKRecord *record = [[CKRecord alloc] initWithRecordType:@"Todo"];

    record[@"title"] = @"Get christmas presents";

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store record id to your local model

    }];
    

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38. CKRecord
    CKRecord *record = [[CKRecord alloc] initWithRecordType:@"Todo"];

    record[@"title"] = @"Get christmas presents";

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store record id to your local model

    }];
    

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39. CKRecord
    CKRecord *record = [[CKRecord alloc] initWithRecordType:@"Todo"];

    record[@"title"] = @"Get christmas presents";

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store record id to your local model

    }];
    

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40. CKRecord
    CKRecord *record = [[CKRecord alloc] initWithRecordType:@"Todo"];

    record[@"title"] = @"Get christmas presents";

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store record id to your local model

    }];
    

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41. CKRecord
    CKRecord *record = [[CKRecord alloc] initWithRecordType:@"Todo"];

    record[@"title"] = @"Get christmas presents";

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store record id to your local model

    }];
    

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42. Container
    Public Database
    Zone
    CKRecord
    Todo
    creationDate
    modificationDate
    title
    

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43. CKRecord
    CKRecordID *recordID = …; // get record id from your model

    [database fetchRecordWithID:recordID

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    record[@"done"] = @YES;

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    // TODO: check & handle error

    }];

    }];
    

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44. CKRecord
    CKRecordID *recordID = …; // get record id from your model

    [database fetchRecordWithID:recordID

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    record[@"done"] = @YES;

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    // TODO: check & handle error

    }];

    }];
    

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45. CKRecord
    CKRecordID *recordID = …; // get record id from your model

    [database fetchRecordWithID:recordID

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    record[@"done"] = @YES;

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    // TODO: check & handle error

    }];

    }];
    

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46. CKRecord
    CKRecordID *recordID = …; // get record id from your model

    [database fetchRecordWithID:recordID

    completionHandler:^(CKRecord *record, NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    record[@"done"] = @YES;

    

    [database saveRecord:record

    completionHandler:^(CKRecord *record, NSError *error) {

    // TODO: check & handle error

    }];

    }];
    

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47. Container
    Public Database
    Zone
    CKRecord
    Todo
    creationDate
    modificationDate
    title
    Todo
    creationDate
    modificationDate
    title
    done
    

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48. CKSubscription
    

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49. CKSubscription
    • Subscribe to push notifications
    • Bound to a record type & predicate
    • on create / on update / on delete
    • silent / badge / alert / sound
    

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50. CKSubscription
    • Configure push notifications
    • Register for push notifications
    • Subscribe to cloud kit
    

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51. CKSubscription
    - (BOOL)application:(UIApplication *)application

    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    [application registerForRemoteNotifications];

    return YES;

    }

    

    - (void)application:(UIApplication *)application

    didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken {

    // trigger subscription

    }
    

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52. CKSubscription
    - (BOOL)application:(UIApplication *)application

    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    [application registerForRemoteNotifications];

    return YES;

    }

    

    - (void)application:(UIApplication *)application

    didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken {

    // trigger subscription

    }
    

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53. CKSubscription
    - (BOOL)application:(UIApplication *)application

    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    [application registerForRemoteNotifications];

    return YES;

    }

    

    - (void)application:(UIApplication *)application

    didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken {

    // trigger subscription

    }
    

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54. CKSubscription
    NSPredicate *predicate = [NSPredicate predicateWithValue:YES];

    

    CKSubscriptionOptions options = (

    CKSubscriptionOptionsFiresOnRecordUpdate |

    CKSubscriptionOptionsFiresOnRecordDeletion |

    CKSubscriptionOptionsFiresOnRecordCreation);

    

    CKSubscription *subscription = [[CKSubscription alloc]

    initWithRecordType:@"Todo"

    predicate:predicate

    options:options];
    

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55. CKSubscription
    NSPredicate *predicate = [NSPredicate predicateWithValue:YES];

    

    CKSubscriptionOptions options = (

    CKSubscriptionOptionsFiresOnRecordUpdate |

    CKSubscriptionOptionsFiresOnRecordDeletion |

    CKSubscriptionOptionsFiresOnRecordCreation);

    

    CKSubscription *subscription = [[CKSubscription alloc]

    initWithRecordType:@"Todo"

    predicate:predicate

    options:options];
    

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56. CKSubscription
    NSPredicate *predicate = [NSPredicate predicateWithValue:YES];

    

    CKSubscriptionOptions options = (

    CKSubscriptionOptionsFiresOnRecordUpdate |

    CKSubscriptionOptionsFiresOnRecordDeletion |

    CKSubscriptionOptionsFiresOnRecordCreation);

    

    CKSubscription *subscription = [[CKSubscription alloc]

    initWithRecordType:@"Todo"

    predicate:predicate

    options:options];
    

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57. CKSubscription
    NSPredicate *predicate = [NSPredicate predicateWithValue:YES];

    

    CKSubscriptionOptions options = (

    CKSubscriptionOptionsFiresOnRecordUpdate |

    CKSubscriptionOptionsFiresOnRecordDeletion |

    CKSubscriptionOptionsFiresOnRecordCreation);

    

    CKSubscription *subscription = [[CKSubscription alloc]

    initWithRecordType:@"Todo"

    predicate:predicate

    options:options];
    

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58. CKSubscription
    CKNotificationInfo *notificationInfo = [CKNotificationInfo new];

    notificationInfo.shouldSendContentAvailable = YES;

    

    subscription.notificationInfo = notificationInfo;

    

    [database saveSubscription:subscription

    completionHandler:^(CKSubscription *subscription,

    NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store subscription id

    }];
    

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59. CKSubscription
    CKNotificationInfo *notificationInfo = [CKNotificationInfo new];

    notificationInfo.shouldSendContentAvailable = YES;

    

    subscription.notificationInfo = notificationInfo;

    

    [database saveSubscription:subscription

    completionHandler:^(CKSubscription *subscription,

    NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store subscription id

    }];
    

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60. CKSubscription
    CKNotificationInfo *notificationInfo = [CKNotificationInfo new];

    notificationInfo.shouldSendContentAvailable = YES;

    

    subscription.notificationInfo = notificationInfo;

    

    [database saveSubscription:subscription

    completionHandler:^(CKSubscription *subscription,

    NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store subscription id

    }];
    

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61. CKSubscription
    CKNotificationInfo *notificationInfo = [CKNotificationInfo new];

    notificationInfo.shouldSendContentAvailable = YES;

    

    subscription.notificationInfo = notificationInfo;

    

    [database saveSubscription:subscription

    completionHandler:^(CKSubscription *subscription,

    NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store subscription id

    }];
    

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62. CKSubscription
    CKNotificationInfo *notificationInfo = [CKNotificationInfo new];

    notificationInfo.shouldSendContentAvailable = YES;

    

    subscription.notificationInfo = notificationInfo;

    

    [database saveSubscription:subscription

    completionHandler:^(CKSubscription *subscription,

    NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store subscription id

    }];
    

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63. CKSubscription
    CKNotificationInfo *notificationInfo = [CKNotificationInfo new];

    notificationInfo.shouldSendContentAvailable = YES;

    

    subscription.notificationInfo = notificationInfo;

    

    [database saveSubscription:subscription

    completionHandler:^(CKSubscription *subscription,

    NSError *error) {

    if (error) {

    // TODO: handle error

    return;

    }

    // TODO: store subscription id

    }];
    

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64. CKSubscription
    - (void)application:(UIApplication *)application

    didReceiveRemoteNotification:(NSDictionary *)userInfo

    fetchCompletionHandler:

    (void(^)(UIBackgroundFetchResult))completionHandler {

    

    // TODO: fetch updates and handle them

    completionHandler(UIBackgroundFetchResultNewData);

    

    }
    

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65. CKSubscription
    - (void)application:(UIApplication *)application

    didReceiveRemoteNotification:(NSDictionary *)userInfo

    fetchCompletionHandler:

    (void(^)(UIBackgroundFetchResult))completionHandler {

    

    // TODO: fetch updates and handle them

    completionHandler(UIBackgroundFetchResultNewData);

    

    }
    

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66. CKSubscription
    - (void)application:(UIApplication *)application

    didReceiveRemoteNotification:(NSDictionary *)userInfo

    fetchCompletionHandler:

    (void(^)(UIBackgroundFetchResult))completionHandler {

    

    // TODO: fetch updates and handle them

    completionHandler(UIBackgroundFetchResultNewData);

    

    }
    

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67. CKSubscription
    • mark notifications as read
    • fetch missed notifications
    • handle badges on all devices
    

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68. // TODO: handle error
    

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69. // TODO: handle error
    • You need to handle them
    • Otherwise your data models will become inconsistent
    • They might occur often
    

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70. // TODO: handle error
    • Handle errors in a central place if possible
    • HRSCustomErrorHandling might help you
    

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71. // TODO: handle error
    CloudKit
    Transaction cache
    Data model
    

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72. // TODO: handle error
    CloudKit
    Transaction cache
    Data model
    

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73. Problems
    

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74. Problems
    • convenient API can not handle complexity of CloudKit
    • lack of documentation
    • strange behavior
    • iOS simulator is not working
    • privileges handling is lacking features
    

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75. Next steps
    

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76. Next steps
    • experiment with the convenient api
    • check if CloudKit is the right iCloud api for your task
    • move to the operation based api
    • get your models together
    

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77. Feedback / Questions
    @_mochs
    ios-coding.com
    

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78. Thank you
    

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