Losing reference to variable while using SocketIO in swift 4 - swift

Question

I'm new to Swift and have always been a bit messy when it comes to developing for iOS so bear with me.
So in my AppDelegate I have a variable like such
var manager = Manager()
and in didFinishLaunchingWithOptions I've got
let controller = ChatRoomViewController()
self.manager.delegate = controller
self.manager.setup()
self.manager.attemptToIdentify(user:username);
In the Manager I've got
var connectionManager = SocketManager(socketURL: URL(string: "http://0.0.0.0:8080")!)
var usersName = ""
var socket:SocketIOClient!
func setup(){
connectionManager.reconnects = true
socket = connectionManager.defaultSocket;
self.setSocketEvents();
socket.connect();
}
This works and I'm able to open up a socket which displays the username on the node.js server. Now when I navigate away from the main view to the chat controller and call
appDelegate.manager.attemptMessage(msg: message);
the console tells me that I'm no longer connected. Best I can tell, I'm losing the reference to one of my variables.

Answer 1

I don't think you should declare your variable in the AppDelegate.
I am using Socket.IO too in one of my app and I prefer use it from a shared instance class. I don't know if you are familar with it, but it is a common architecture in iOS development.
It is based on a singleton instance and allows you to keep instance of variables in memory during all the life of the app.
For you case, you can do the following for example:
private let _managerSharedInstance = Manager()
class Manager() {
private var connectionManager = SocketManager(socketURL: URL(string: "http://0.0.0.0:8080")!)
private var usersName = ""
private var socket:SocketIOClient!
var delegate: UIViewController?
class var shared: Manager {
return _managerSharedInstance
}
init() {
connectionManager.reconnects = true
socket = connectionManager.defaultSocket;
setSocketEvents();
socket.connect();
}
private func setSocketEvents() {
// Your socket events logic
}
func attemptToIdentify(user username: String) {
socket.emit("identify", ["username": username])
}
func attemptToSend(message: String) {
socket.emit("message", ["username": username, "message": message])
}
}
So, in your AppDelegate.didFinishLaunchingWithOptions, you can now call:
Manager.shared.attemptToIdentify(user: username)
You can call this from everywhere in your code, the shared class variable will return the instance of _managerSharedInstance.
By the way, you should set your delegate of the controller in the viewWillAppear of that controller and not in the AppDelegate.
func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
Manager.shared.delegate = self
}

Answer 2

You set controller variable's object in didFinishLaunchingWithOptions method to your manager's delegate. But when you navigate ChatRoomViewController on UI, you open another ChatRoomViewController object.
You should set manager's delegate in your ChatRoomViewController class' viewDidLoad method like this
class ChatRoomViewController: UIViewController{
override func viewDidLoad(){
super.viewDidLoad()
appDelegate.manager.delegate = self
}
}