Practical CloudKit

iOSDC 2017 day 2

I talked about sync.

Transcript

1. J04%$
   Practical
   CloudKit
   

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2. @nakajijapan
   Software Engineer
   Cookpad Inc.
   iOS / Web / OS X
   

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3. NKJMultiMovieCaptureView
   NKJMovieComposer
   NKJPagerViewController
   PhotoSlider
   Teiten
   GitHub
   Sengiri
   Shari
   Ajimi
   Kazaguruma
   iOSDC 2017
   

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4. Agenda
   • Background
   • What is CloudKit ?
   • About sync
   • Wrap up
   

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5. Background
   

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6. Background
   • Want the memo application for myself
   • Want to apply color in markdown only
   • Don’t need the rich editor
   • Make it available to use everywhere
   

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10. What is CloudKit?
    

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11. What is CloudKit?
    

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12. What is CloudKit?
    • Access to iCloud servers
    • Supported on OS X and iOS and Web
    • Uses iCloud accounts
    • Public and private databases
    • Structured and bulk data
    • Transport, not local persistence
    

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13. Default Zone
    Public Database
    CloudKit Container
    Default Zone
    Default Zone
    Record
    Default Zone
    Private Database
    Default Zone
    Default Zone
    Record
    Custom Zone
    Default Zone
    Default Zone
    Record
    Shared Zone
    Shared Database
    Default Zone
    Default Zone
    Record
    

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14. Default Zone
    Public Database
    CloudKit Container
    Default Zone
    Default Zone
    Record
    Default Zone
    Private Database
    Default Zone
    Default Zone
    Record
    Custom Zone
    Default Zone
    Default Zone
    Record
    Shared Zone
    Shared Database
    Default Zone
    Default Zone
    Record
    

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15. Why
    

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16. Why?
    • Authentication
    • Use iCloud Account
    • PushNotification
    • Don’t need to prepare the certificate
    

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17. Why?
    • Authentication
    • Use iCloud Account
    • PushNotification
    • Don’t need to prepare the certificate
    • A genuine interest
    

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18. Core Data iCloud
    

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19. Core Data iCloud
    As of macOS v10.12 and iOS 10.0; Core Data's iCloud integration
    feature has been deprecated. Apps will continue to work. There are
    no changes to or removal of the functionality in macOS 10.12 and
    iOS 10. Historically, deprecated symbols in Cocoa remain functional
    for a considerable period of time before removal. Only the client side
    Core Data iCloud API symbols are deprecated. Core Data with iCloud
    is built on top of the iCloud Drive service. The service pieces are not
    effected in any way. If and when the deprecated APIs are disabled in
    some future OS version, applications running on iOS 9 or 10 will
    continue to work.
    IUUQTEFWFMPQFSBQQMFDPNMJCSBSZDPOUFOUSFMFBTFOPUFT(FOFSBM8IBU/FX$PSF%BUB3FMFBTF/PUFTIUNM
    

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20. Core Data iCloud
    As of macOS v10.12 and iOS 10.0; Core Data's iCloud integration
    feature has been deprecated. Apps will continue to work. There are
    no changes to or removal of the functionality in macOS 10.12 and
    iOS 10. Historically, deprecated symbols in Cocoa remain functional
    for a considerable period of time before removal. Only the client side
    Core Data iCloud API symbols are deprecated. Core Data with iCloud
    is built on top of the iCloud Drive service. The service pieces are not
    effected in any way. If and when the deprecated APIs are disabled in
    some future OS version, applications running on iOS 9 or 10 will
    continue to work.
    IUUQTEFWFMPQFSBQQMFDPNMJCSBSZDPOUFOUSFMFBTFOPUFT(FOFSBM8IBU/FX$PSF%BUB3FMFBTF/PUFTIUNM
    

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21. CloudKit
    

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22. The thing we should
    think when we make
    the app such that.
    

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24. Sync
    

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25. Sync
    

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26. Sync
    • Subscribe to changes
    • Fetch server changes
    • Save server changes and token
    • Send changes to the server
    • Track local changes
    • Resolve conflicts
    

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27. Online
    

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28. Online
    

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29. Offline
    

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30. Offline
    

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31. Subscribe to changes
    

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32. Subscribe to changes
    • On app launch
    • Prepare for fetching server changes
    • Setup the push notifications for changes
    

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33. Subscribe to changes
    privateCloudDatabase.fetchAllSubscriptions { subscriptions, error in
    guard let subscriptions = subscriptions else { return }
    guard subscriptions.isEmpty else { return }
    let predicate = NSPredicate(value: true)
    let querySubscription = CKQuerySubscription(
    recordType: "Notes",
    predicate: predicate,
    options: [
    .firesOnRecordCreation,
    .firesOnRecordUpdate,
    .firesOnRecordDeletion
    ])
    let notification = CKNotificationInfo()
    notification.alertBody = "A note was changed or deleted"
    notification.shouldBadge = true
    notification.shouldSendContentAvailable = true
    querySubscription.notificationInfo = notification
    self.privateCloudDatabase.save(querySubscription) { subscription, error in
    // Check Error
    }
    }
    

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34. Subscribe to changes
    privateCloudDatabase.fetchAllSubscriptions { subscriptions, error in
    guard let subscriptions = subscriptions else { return }
    guard subscriptions.isEmpty else { return }
    let predicate = NSPredicate(value: true)
    let querySubscription = CKQuerySubscription(
    recordType: "Notes",
    predicate: predicate,
    options: [
    .firesOnRecordCreation,
    .firesOnRecordUpdate,
    .firesOnRecordDeletion
    ])
    let notification = CKNotificationInfo()
    notification.alertBody = "A note was changed or deleted"
    notification.shouldBadge = true
    notification.shouldSendContentAvailable = true
    querySubscription.notificationInfo = notification
    self.privateCloudDatabase.save(querySubscription) { subscription, error in
    // Check Error
    }
    }
    Fetch All Sbuscriptions
    

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35. Subscribe to changes
    privateCloudDatabase.fetchAllSubscriptions { subscriptions, error in
    guard let subscriptions = subscriptions else { return }
    guard subscriptions.isEmpty else { return }
    let predicate = NSPredicate(value: true)
    let querySubscription = CKQuerySubscription(
    recordType: "Notes",
    predicate: predicate,
    options: [
    .firesOnRecordCreation,
    .firesOnRecordUpdate,
    .firesOnRecordDeletion
    ])
    let notification = CKNotificationInfo()
    notification.alertBody = "A note was changed or deleted"
    notification.shouldBadge = true
    notification.shouldSendContentAvailable = true
    querySubscription.notificationInfo = notification
    self.privateCloudDatabase.save(querySubscription) { subscription, error in
    // Check Error
    }
    }
    Should control the
    registration of subscription
    ourself
    

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36. Subscribe to changes
    privateCloudDatabase.fetchAllSubscriptions { subscriptions, error in
    guard let subscriptions = subscriptions else { return }
    guard subscriptions.isEmpty else { return }
    let predicate = NSPredicate(value: true)
    let querySubscription = CKQuerySubscription(
    recordType: "Notes",
    predicate: predicate,
    options: [
    .firesOnRecordCreation,
    .firesOnRecordUpdate,
    .firesOnRecordDeletion
    ])
    let notification = CKNotificationInfo()
    notification.alertBody = "A note was changed or deleted"
    notification.shouldBadge = true
    notification.shouldSendContentAvailable = true
    querySubscription.notificationInfo = notification
    self.privateCloudDatabase.save(querySubscription) { subscription, error in
    // Check Error
    }
    }
    @available(iOS 10.0, *)
    public struct CKQuerySubscriptionOptions : OptionSet {
    public init(rawValue: UInt)
    public static var firesOnRecordCreation: CKQuerySubscriptionOptions { get }
    public static var firesOnRecordUpdate: CKQuerySubscriptionOptions { get }
    public static var firesOnRecordDeletion: CKQuerySubscriptionOptions { get }
    public static var firesOnce: CKQuerySubscriptionOptions { get }
    }
    

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37. Subscribe to changes
    privateCloudDatabase.fetchAllSubscriptions { subscriptions, error in
    guard let subscriptions = subscriptions else { return }
    guard subscriptions.isEmpty else { return }
    let predicate = NSPredicate(value: true)
    let querySubscription = CKQuerySubscription(
    recordType: "Notes",
    predicate: predicate,
    options: [
    .firesOnRecordCreation,
    .firesOnRecordUpdate,
    .firesOnRecordDeletion
    ])
    let notification = CKNotificationInfo()
    notification.alertBody = "A note was changed or deleted"
    notification.shouldBadge = true
    notification.shouldSendContentAvailable = true
    querySubscription.notificationInfo = notification
    self.privateCloudDatabase.save(querySubscription) { subscription, error in
    // Check Error
    }
    }
    Set for push the notification
    

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38. Fetch sever changes
    

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39. Fetch sever changes
    • On app launch
    • On push from CloudKit
    

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40. Fetch sever changes
    • On app launch
    • On push from CloudKit
    

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41. Fetch sever changes
    var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    

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42. Fetch sever changes
    var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    Assign serverChangeToken for
    getting the records from the
    previous point
    

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43. Fetch sever changes
    var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    

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44. Fetch sever changes
    var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    

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45. Fetch sever changes
    • On app launch
    • On push from CloudKit
    

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46. Fetch sever changes
    let notification = CKNotification(fromRemoteNotificationDictionary: userInfo)
    guard notification.notificationType == CKNotificationType.query { return }
    guard let queryNotification = notification as? CKQueryNotification else { return }
    guard let recordID = queryNotification.recordID else { return }
    switch queryNotification.queryNotificationReason {
    case .recordCreated:
    // check whether data is duplicate
    // save data to CoreData
    case .recordUpdated:
    // get the data from CoreData
    // save data to CoreData
    case .recordDeleted:
    // get the data from CoreData
    // delete data from CoreData
    }
    

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47. Fetch sever changes
    let notification = CKNotification(fromRemoteNotificationDictionary: userInfo)
    guard notification.notificationType == CKNotificationType.query { return }
    guard let queryNotification = notification as? CKQueryNotification else { return }
    guard let recordID = queryNotification.recordID else { return }
    switch queryNotification.queryNotificationReason {
    case .recordCreated:
    // check whether data is duplicate
    // save data to CoreData
    case .recordUpdated:
    // get the data from CoreData
    // save data to CoreData
    case .recordDeleted:
    // get the data from CoreData
    // delete data from CoreData
    }
    optional public func userNotificationCenter(_
    center: UNUserNotificationCenter, willPresent
    notification: UNNotification, withCompletionHandler
    completionHandler: @escaping
    (UNNotificationPresentationOptions) -> Swift.Void)
    •AppKit
    •UIKit
    optional public func application(_ application:
    NSApplication, didReceiveRemoteNotification
    userInfo: [String : Any])
    

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48. Save server changes and token
    

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49. • Delete records from Core Data
    • Use deletedRecordIDs variable
    • Categorize records for updating or creating
    • Use changedRecords variable
    • Update records to Core Data
    • Create records to Core Data
    • Finally save serverChangetoken
    Save server changes and token
    

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50. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    Save server changes and token
    

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51. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    Prepare variables
    Save server changes and token
    

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52. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    Append the record or recordID
    Save server changes and token
    

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53. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    Save server changes and token
    

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54. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    Save server changes and token
    

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55. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    • Delete records from Core Data
    • Use deletedRecordIDs variable
    • Categorize records for updating or creating
    • Use changedRecords variable
    • Update records to Core Data
    • Create records to Core Data
    • Finally save serverChangetoken
    Save server changes and token
    

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56. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    • Delete records from Core Data
    • Use deletedRecordIDs variable
    • Categorize records for updating or creating
    • Use changedRecords variable
    • Update records to Core Data
    • Create records to Core Data
    • Finally save serverChangetoken
    Save server changes and token
    xxxxxxxxxxxxxxx
    

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57. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    • Delete records from Core Data
    • Use deletedRecordIDs variable
    • Categorize records for updating or creating
    • Use changedRecords variable
    • Update records to Core Data
    • Create records to Core Data
    • Finally save serverChangetoken
    Send local changes
    Save server changes and token
    

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58. Track local change
    

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59. Offline
    The application must be available in
    offline, too.
    

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60. Track local change
    

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61. Track local change
    • Should implement in ourself
    • Need to save the deleted record
    • Need to fetch records from the previous point
    • LastSyncedTime: Date
    • Save to UserDefaults
    

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62. Track local change
    • On app launch
    • On available to network
    

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63. Track local change
    • Subscribe to network reachability
    let reachability = Reachability()!
    NotificationCenter.default.addObserver(self,
    selector: #selector(self.reachabilityChanged),
    name: ReachabilityChangedNotification,
    object: reachability
    )
    try! reachability.startNotifier()
    func reachabilityChanged(note: Notification) {
    let reachability = note.object as! Reachability
    if reachability.isReachable {
    // send local change
    }
    }
    In AppDelegate
    with the Reachability
    

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64. var recordZone = CKRecordZone(zoneName: "NotesZone")
    var changedRecords: [CKRecordID: CKRecord] = [:]
    var deletedRecordIDs = Set()
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    let operation = CKFetchRecordZoneChangesOperation(
    recordZoneIDs: [recordZone.zoneID],
    optionsByRecordZoneID: [recordZone.zoneID : options]
    )
    operation.recordChangedBlock = { record in
    changedRecords[record.recordID] = record
    }
    operation.recordWithIDWasDeletedBlock = { recordID, string in
    deletedRecordIDs.insert(recordID)
    changedRecords.removeValue(forKey: recordID)
    }
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // save token
    self.serverChangeToken = serverChangeToken
    }
    • Delete records from Core Data
    • Use deletedRecordIDs variables
    • Categorize records for updating or creating
    • Use changedRecords variables
    • Update records to Core Data
    • Create records to Core Data
    • Finally save serverChangetoken
    Save server changes and token
    Send local changes
    

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65. Send local change
    // Delete Records from iCloud Server
    let operation = CKModifyRecordsOperation(
    recordsToSave: nil,
    recordIDsToDelete: recordIDs
    )
    operation.modifyRecordsCompletionBlock = { (records, recordIDs, error) in
    if let error = error {
    failure(error)
    return
    }
    // Delete Core Data
    }
    privateCloudDatabase.add(operation)
    • Delete records from Core Data and iCloud
    Server
    

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66. Send local change
    let predicate = NSPredicate(format: "modifiedAt > %@", lastSyncedTime)
    query.predicate = predicate
    items.forEach { note in
    if note.recordID != nil {
    note.update()
    } else {
    note.create()
    }
    }
    • Fetch records from Core Data
    • Save(create/update) records from iCloud
    server
    

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67. Send local change
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    (…snip…)
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // Delete Record
    self.sendDeletedRecord {
    // Fetch and save the records created and modified from the previous point
    self.sendRecordChanges {
    // Save the last synced time
    self.lastSyncedTime = Date()
    }
    }
    self.serverChangeToken = serverChangeToken
    }
    self.privateCloudDatabase.add(operation)
    Fetch/Save server changes
    

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68. Send local change
    let options = CKFetchRecordZoneChangesOptions()
    options.previousServerChangeToken = serverChangeToken
    (…snip…)
    operation.recordZoneFetchCompletionBlock = { recordZoneID, serverChangeToken, data, result, error in
    (…snip…)
    // Delete Record
    self.sendDeletedRecord {
    // Fetch and save the records created and modified from the previous point
    self.sendRecordChanges {
    // Save the last synced time
    self.lastSyncedTime = Date()
    }
    }
    self.serverChangeToken = serverChangeToken
    }
    self.privateCloudDatabase.add(operation)
    Send local changes
    Fetch/Save server changes
    

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69. Conflict
    

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70. Conflict
    • CKRecordSavePolicy
    • ifServerRecordUnchanged
    • changedKeys
    • allKeys
    

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71. Conflict
    • CKRecordSavePolicy
    • ifServerRecordUnchanged default
    • changedKeys
    • allKeys
    

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72. Wrup up
    

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73. Sync
    • Subscribe to changes
    • Fetch server changes
    • Save server changes and token
    • Send changes to the server
    • Track local changes
    • Resolve conflicts
    

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74. View Slide

75. Thanks.
    
    

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76. View Slide