How to use iCloud with swift data

To use iCloud with SwiftData, you can leverage CloudKit for synchronization. Here are the steps and relevant information from the WWDC sessions:

1. Adopt SwiftData:

   • SwiftData is a framework that makes it easy to build your app's model layer and persist it across launches of your app. It provides persistence, modeling, migration, graph management, and synchronization with CloudKit.
   • To use SwiftData with models in your app, import the framework and decorate each model with the @Model macro. This allows your views to fetch models from the model container and populate the view using queries.

   What’s new in SwiftData (00:01:01)

2. Sync with CloudKit:

   • Enable CloudKit under iCloud services and create a new container for syncing your data.
   • Add background modes and enable the remote notifications capability to process remote changes in the background.
   • Update your configuration to include the CloudKit container option and pass in your new container's ID.

   Customize feature discovery with TipKit (00:11:20)

3. Handle Cloud Saves:

   • Use a cloud save manager class to handle syncing. Set it up using your iCloud identifier and specify an existing folder containing saved data.
   • At game launch, call sync and pass a completion handler block to handle any merge conflicts between local data and cloud data.
   • To save progress to the cloud, call upload every time you write into save files, and pass a completion handler to resolve any conflicts.

   Port advanced games to Apple platforms (00:19:28)

4. Track Model Changes:

   • SwiftData provides access to the history of changes in a datastore, which is useful for tracking local changes that need to be synced to a remote web service.
   • You can migrate to SwiftData history if you are using coexistence with CoreData to benefit from persistent history.

   Track model changes with SwiftData history (00:16:20)

By following these steps, you can effectively use iCloud with SwiftData to synchronize your app's data across devices.