Implementing SwiftData components

Now that you have used the JournalEntry class to create a JournalEntry model, you will create a singleton class that contains a ModelContainer object and a ModelContext instance. You will then add methods to manipulate instances of the JournalEntry model stored in ModelContext.

The term singleton means that there is only one instance of this class in your app, and this is also applicable when you create your own apps that use SwiftData.

Follow these steps:

1. Right-click the JRNL folder in the Project navigator and choose New File... from the pop-up menu.
2. iOS should already be selected. Choose Swift File and then click Next.
3. Name this file SharedData. Click Create. The SharedData file appears in the Project navigator.
4. Add the following code after the import statement:

   import SwiftData
   

   This lets you use the SwiftData framework.

5. Add the following code after the import...