Learn Courses My Dashboard

How to handle fatalError

In the PersistenceController private init function, there is this code:

        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                // replace this implementation with code to handle the error appropriately
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                /*
                Typical reasons for an error here include:
                * The parent directory does not exist, cannot be created, or disallows writing.
                * The persistent store is not accessible, due to permissions or data protection when the device is locked.
                * The device is out of space.
                * The store could not be migrated to the current model version.
                Check the error message to determine what the actual problem was.
                */
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })

PersistenceController is used in the main swift file with:

@main
struct HappyTeenApp: App {
    
    let persistenceController = PersistenceController.shared
    @State private var store = GradientModelStore.defaultStore

    var body: some Scene {
        WindowGroup {
            WelcomeView(store: $store)
                .environment(\.managedObjectContext, persistenceController.container.viewContext) // Core Data Managed Object Context
        }
    }
}

How can I replace the fatalError code by sending an alert to the user when this error occurs?
What are you suggesting to do?

When you include code in your post you should format the code as a “Code Block”.

To format the code nicely, place 3 back-ticks ``` on the line above your code and 3 back-ticks ``` on the line below your code. Like this:

```
Code goes here
```

The 3 back-ticks must be the ONLY characters on the line. The back-tick character is located on the same keyboard key as the tilde character ~ (which is located below the Esc key).

Alternatively after you paste in your code, select that code block and click the </> button on the toolbar. This does the same thing as manually typing the 3 back ticks on the line above and below your code.

This also makes it easier for anyone assisting as they can copy the code and carry out some testing.

With regard to dealing with errors:
You could display and alert by adding an .alert() modifier to your View which is triggered by a boolean that is set to true in your test for an error. You should also set a message variable appropriate to the error encountered that you can use in the alert message so the user knows what is going on and perhaps includes advice on what to do.