I am learning Core Data, I feel it's really cool to use @Environment to access Core Data.

But I want to creat a Class to add some items to Core Data.

Could I add .environment(.managedObjectContext, persistenceController.container.viewContext) to a Class or a struct? Or this is some similar way to access Core Data as easy as @Environment(.managedObjectContext) var moc

The majority of your Core Data work involves using the managed object context aka moc. This means the observable object (class) will have to get access to the moc in some way. You can use injection option that works by passing the moc you want to use into the observable object when it is created. Example: Managed Object Context -> ObservableObject -> SwiftUI View

let moc = MyContainer().persistentContainer.viewContext
let oo = MyObservableObject(moc: moc)
MyView(oo: oo)

Hi @ygeras Thanks for your reply, please forgive my ignorance, I am learning. let me explain what I thought more detail.

use @Environment(.managedObjectContext) var moc, I feel the code looks so natrure.

In this Paul's Article "How to add Core Data objects from SwiftUI views" https://www.hackingwithswift.com/quick-start/swiftui/how-to-add-core-data-objects-from-swiftui-views

we could get access the by one line of code let language = ProgrammingLanguage(context: managedObjectContext) which looks so cool.

Other article when add object to Core Data, it has to use forKey, like this

let entity = NSEntityDescription.entity(forEntityName: "Users", in: context)
let newUser = NSManagedObject(entity: entity!, insertInto: context)

newUser.setValue("Abhishek", forKey: "username")
newUser.setValue("2311", forKey: "password")
newUser.setValue("21", forKey: "age")

How to make code as simple as the first one?

No worries at all. So if you go through the same preparatory setup as in Paul's video. That is, create entity Users with attributes username, password, and age as well as setup moc. You will be able to do absolutely the same here.

let newUser = Users(context: managedObjectContext)
newUser.username = "Abhishek"
newUser.password = "23111"
newUser.age = 21 // or if set it up as String "21"

Hi @ygeras ,

Thank you, I found it.

static func loadDataToCD(moc: NSManagedObjectContext) {
           let newUser = User(context: moc)
}

I know it will call this func somewhere else, but just tell moc you are NSManagedObjectContext, then I can get the User Class, how it happened?

is that magic?

Could I add .environment(.managedObjectContext, persistenceController.container.viewContext) to a Class or a struct?

No, the environment only exists in a View.

Hi @ygeras thank you for you detail explaination, I feel I got the courage to dig deeper.