How do i refresh a TableView after some data will changed? - arrays

Question

I want to change the list of users in only one class, called Network. And i don't understand how to make a TableView update after the userList has changed. I'll show you an example and detailed question in code below.
// Network.swift
class Network {
var userList: [User] = []
// Next functions may change userList array
// For example, the data came from the server, and update the userList with new data
}
// App delegate
class AppDelegate: UIResponder, UIApplicationDelegate {
var network: Network = Network()
..
}
// File TableViewController.swift
class TableViewController: UITableViewController {
…
var userList: [User] = [] // Here I want to have a full copy of the array from Network class
override func viewDidLoad() {
super.viewDidLoad()
let appDelegate = UIApplication.shared.delegate as! AppDelegate
self.userList = appDelegate.network.userList // Just copy an array
// And I want that after each update appDelegate.network.userList I updated the table, how to do it better?
self.tableView.reloadData()
}
}

Answer 1

As #JDM mentioned in comment your architecture is messed.
Try to do this delegation using protocols:
// Network.swift
protocol UsersUpdatedProtocol {
func usersListUpdated(list: [User])
}
class Network {
var userList: [User] = [] {
didSet {
delegate?.usersListUpdated(list: userList)
}
}
var delegate: UsersUpdatedProtocol?
init(delegate d: UsersUpdatedProtocol) {
super.init()
delegate = d
}
}
// File TableViewController.swift
class TableViewController: UITableViewController, UsersUpdatedProtocol {
var userList: [User] = []
override func viewDidLoad() {
super.viewDidLoad()
let _ = Network(delegate: self)
}
func usersListUpdated(list: [User]) {
self.userList = list
self.tableView.reloadData()
}
}

Answer 2

You could use a notification. Whenever the userlist gets updated, post a notification like this:
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "UserlistUpdate"), object: nil)
Then, in viewDidLoad add:
NotificationCenter.default.addObserver(self, selector: #selector(TableViewController.reloadData), name: NSNotification.Name(rawValue: "UserlistUpdate"), object: nil)
P.S. regarding your architecture so far, I would make the TableViewController hold a variable for Network rather than hold its own user array. Then, in AppDelegate:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
let network = Network()
// Access the TableViewController and set its network variable
let tableViewController = window!.rootViewController as! TableViewController
tableViewController.network = network