Core Data

1. Model Setup

Tạo .xcdatamodeld file trong Xcode và define entities.

2. NSManagedObject

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

3. Container

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)
        }
    }
}

4. @FetchRequest

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)
        }
    }
}

5. CRUD Operations

@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()
}

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📝 Recommend

• Dự án mới: Dùng SwiftData (iOS 17+)
• Legacy/Complex: Core Data vẫn mạnh mẽ