46.2 App Groups and UserDefaults

Much about the way in which the app has been constructed will be familiar from techniques outlined in previous chapters of the book. The project also makes use of app storage in the form of UserDefaults and the @AppStorage property wrapper, concepts which were introduced in the chapter entitled “SwiftUI Data Persistence using AppStorage and SceneStorage”. The ShortcutDemo app uses app storage to store an array of objects containing the symbol, quantity and time stamp data for all stock purchase transactions. Since this is a test app that needs to store minimal amounts of data, this storage is more than adequate. In a real-world environment, however, a storage system capable of handling larger volumes of data such as SQLite, CoreData or iCloud storage would need to be used.

In order to share the UserDefaults data between the app and the SiriKit intents extension, the project also makes use of App Groups. App Groups allow apps to share...