Swift threading multiple tasks?

Question

I have this label that is supposed to display a username. Now, I have done quite a bit of IOS developing, however threading is still a bit unclear to me. How would I make sure this code finishes:

User(name: "", email: "", _id: "").getCurrentUser(userId: userId)

Before this gets excecuted?:

self.nameLabel.text = currentUser.name

I have been fumbling with DispatchQueue but I can't seem to figure it out... Thx in advance!

Answer 1

Just send a notification in your getCurrentUser() method and add an observer in your UIViewController to update the label.

public extension Notification.Name {
    static let userLoaded = Notification.Name("NameSpace.userLoaded")
}

let notification = Notification(name: .userLoaded, object: user, userInfo: nil)
NotificationCenter.default.post(notification)

And in your UIViewController:

NotificationCenter.default.addObserver(
        self,
        selector: #selector(self.showUser(_:)),
        name: .userLoaded,
        object: nil)

func showUser(_ notification: NSNotification) {
    guard let user = notification.object as? User,
        notification.name == .userLoaded else {
            return
    }
    currentUser = user
    DispatchQueue.main.async {
        self.nameLabel.text = self.currentUser.name
    }
}