Backup and restore to iCloud

gistfile1.rb

  def backup
    error_ptr = Pointer.new(:object)
    fileManager = NSFileManager.defaultManager
    # iCloud
    icloud = fileManager.URLForUbiquityContainerIdentifier(nil)
    Logger.debug "iCloud at #{NSHomeDirectory().stringByAppendingPathComponent( "Documents/")}"

    if icloud
      icloud_url = icloud.URLByAppendingPathComponent("Documents/cd_backup.sqlite")
      a = fileManager.startDownloadingUbiquitousItemAtURL(icloud_url, error:error_ptr)
      Logger.debug "iCloud URL at #{icloud_url.path}"
      Logger.debug "iCloud downloaded? #{a}"

      if fileManager.fileExistsAtPath(icloud_url.path)
        BW::UIAlertView.new({
          title: 'Found a previous backup',
          message: "There is a backup file in iCloud, would like to overwirte this backup?",
          buttons: ['Don\'t backup now', 'Backup right now'],
          cancel_button_index: 0
        }) do |alert|
          if alert.clicked_button.cancel?
            # puts 'Canceled'
          else
            # Remove this file in iCloud
            fileManager.removeItemAtURL(icloud_url, error:error_ptr)
            backup_to(icloud_url)
          end
        end.show
      else
        backup_to(icloud_url)
      end
    else
      App.alert("iCloud not woking on your device.")
    end
  end
  def backup_to(path)
    error_ptr = Pointer.new(:object)
    App.delegate.persistentStoreCoordinator.persistentStores.each do |persistentStore|
      SVProgressHUD.show
      App.delegate.persistentStoreCoordinator.migratePersistentStore(persistentStore, toURL:path, options:nil, withType:NSSQLiteStoreType, error:error_ptr)
      SVProgressHUD.dismiss
      App.alert("Backup successful!")
    end
  end

  def restore
    error_ptr = Pointer.new(:object)
    fileManager = NSFileManager.alloc.init

    # iCloud
    icloud = NSFileManager.defaultManager.URLForUbiquityContainerIdentifier(nil)

    if icloud
      icloud_url = icloud.URLByAppendingPathComponent("Documents/cd_backup.sqlite")
      a = fileManager.evictUbiquitousItemAtURL(icloud_url, error:error_ptr)
      b = fileManager.startDownloadingUbiquitousItemAtURL(icloud_url, error:error_ptr)
      Logger.debug "iCloud URL at #{icloud_url.path}"
      Logger.debug "iCloud evicted? #{a} and downloaded? #{b}"

      if fileManager.fileExistsAtPath(icloud_url.path)
        App.delegate.persistentStoreCoordinator.persistentStores.each do |persistentStore|
          SVProgressHUD.show
          App.delegate.persistentStoreCoordinator.removePersistentStore(persistentStore, error:error_ptr)

          if fileManager.fileExistsAtPath(App.delegate.sqlite_path)
            storeDirectory = App.delegate.sqlite_url.URLByDeletingLastPathComponent
            enumerator = fileManager.enumeratorAtURL(storeDirectory, includingPropertiesForKeys:nil, options:0, errorHandler:nil)
            storeName = App.delegate.sqlite_url.lastPathComponent.stringByDeletingPathExtension
            enumerator.each do |url|
              unless url.lastPathComponent.hasPrefix(storeName)
                next
              end
              fileManager.removeItemAtURL(url, error:error_ptr)
            end
          end

          # Copy the new data file
          fileManager.copyItemAtPath(icloud_url.path, toPath:App.delegate.sqlite_path, error:error_ptr)
          App.delegate.persistentStoreCoordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: App.delegate.sqlite_url, options: App.delegate.persistent_store_options, error: error_ptr)
          SVProgressHUD.dismiss
          App.alert("Restroe successful!")
        end
      else
        App.alert("Didn't find any backup file in your iCloud, can't restore now!")
      end
    else
      App.alert("iCloud not woking on your device.")
    end
  end

Warning. This code does not work correctly. See lines 10 and 56. startDownloadingUbiquitousItemAtURL is asynchronous.