Core Data

@objc(Todo)
class Todo: NSManagedObject {
    @NSManaged var title: String
    @NSManaged var isComplete: Bool
    @NSManaged var createdAt: Date
}

struct PersistenceController {
    static let shared = PersistenceController()
    
    let container: NSPersistentContainer
    
    init() {
        container = NSPersistentContainer(name: "Model")
        container.loadPersistentStores { _, error in
            if let error = error {
                fatalError("Core Data failed: \(error)")
            }
        }
    }
}
 
@main
struct MyApp: App {
    let persistence = PersistenceController.shared
    
    var body: some Scene {
        WindowGroup {
            ContentView()
                .environment(\.managedObjectContext, persistence.container.viewContext)
        }
    }
}

struct TodoList: View {
    @FetchRequest(
        sortDescriptors: [SortDescriptor(\.createdAt, order: .reverse)],
        predicate: NSPredicate(format: "isComplete == false")
    )
    var todos: FetchedResults<Todo>
    
    var body: some View {
        List(todos) { todo in
            Text(todo.title)
        }
    }
}

@Environment(\.managedObjectContext) var context
 
func create() {
    let todo = Todo(context: context)
    todo.title = "New Task"
    todo.createdAt = Date()
    try? context.save()
}
 
func delete(_ todo: Todo) {
    context.delete(todo)
    try? context.save()
}