Why is my posted notification not being received in my Swift iOS app

Question

I have three custom swift classes in my app. One is a NetworkServices class and the other two are custom UIViewController classes. The NetworkServices class posts a notification to the other two classes when wifi is turned on and there is a.network connection and also when wifi is turned off and there is no.network connection. Currently, the app starts up posting the isConnected notification and code executes as expected. I then turn off wifi and isDisconnected is posted and code executes as expected. However, when I then turn wifi back on again the isConnected post is sent but it is not received by either of the two custom UIViewController classes. My problem is why not?

here are relevant lines of code in my NetworkServices class;

protocol NetworkServicesDelegate: AnyObject {
    func sendStockInfo(stocksInfo: [String: StockInfo])
}

final class NetworkServices {
    
    static let sharedInstance = NetworkServices()

...

    public func startMonitoring() {
        monitor.start(queue: queue)
        
        self.monitor.pathUpdateHandler = { [weak self] path in
            if path.status == .satisfied {
                // connect the socket
                self?.socket.connect()
                print("DEBUG: self?.socket.connect() called")
            } else {
                // disconnect the socket
                self?.socket.disconnect()
//                print("DEBUG: self?.socket.disconnect() called")
                self?.isConnected = false
                // post notification that socket is now disconnected
                DispatchQueue.main.async {
                    print("DEBUG: Notification.Name(rawValue) called")
                    let name = Notification.Name(rawValue: isDisconnectedNotificationKey)
                    NotificationCenter.default.post(name: name, object: nil)
                }
            }
        }
    }
...
    
}

extension NetworkServices: WebSocketDelegate {
    
    func didReceive(event: WebSocketEvent, client: WebSocket) {
        
        switch event {
        case .connected(_):
            self.isConnected = true
            // post notification that socket is now connected
            let name = Notification.Name(rawValue: isConnectedNotificationKey)
            NotificationCenter.default.post(name: name, object: nil)
            print("DEBUG: Notification isConnected posted")

        case .disconnected(let reason, let code):
            print("DEBUG: Got disconnected reason = \(reason) code = \(code)")
            self.isConnected = false

        case .cancelled:
            print("DEBUG: cancelled.")
            // reconnect socket
            socket.connect()
            self.isConnected = true

        case .reconnectSuggested(let suggestReconnect):
            print("DEBUG: suggestReconnect = \(suggestReconnect)")
            // post notification that socket is not connected
            
        case .viabilityChanged(let viabilityChanged):
            print("DEBUG: viabilityChanged = \(viabilityChanged)")
            
        case .error(let error):
            print("DEBUG error: \(String(describing: error?.localizedDescription))")
            
        case .text(let socketString):
//            print("DEBUG: .text available")
            parseJSONSocketData(socketString)
            
        default:
            break
        }
    }
}

Here are the relevant lines of code from my two custom UIViewController classes;

protocol CompanyPriceListDelegate: AnyObject {
    func sendPriceHistory(_ priceHistory: PriceHistory)
}

class CompanyPriceListVC: UITableViewController {
    
...
    
    let isConnected = Notification.Name(rawValue: isConnectedNotificationKey)
    let isNotConnected = Notification.Name(rawValue: isDisconnectedNotificationKey)
        
    override func viewDidLoad() {
        super.viewDidLoad()
        
...        
        createObservers()
...     
    }
    
    deinit {
        NotificationCenter.default.removeObserver(self)
    }
    
    private func createObservers() {
        print("DEBUG: createObservers() called")
        NotificationCenter.default.addObserver(self, selector: #selector(CompanyPriceListVC.dismissAndFetchStockInfo), name: isConnected, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(CompanyPriceListVC.notifyUserOnScreen(notification:)), name: isNotConnected, object: nil)
    }
    
    @objc private func fetchStockInfo() {
            NetworkServices.sharedInstance.fetchStockInfo(symbols: companyStockSymbols, delegate: self)
    }

    @objc private func notifyUserOnScreen(notification: NSNotification) {
        self.present(alertController, animated: true)
    }
    
    @objc public func dismissAndFetchStockInfo() {

        if presentedViewController == alertController {
            self.alertController.dismiss(animated: true, completion: nil)
        }
        fetchStockInfo()
    }
...
    
}

//
//  CompanyDetailsVC.swift
//  BetVictorTask
//
//  Created by Stephen Learmonth on 02/03/2022.
//

import UIKit

class CompanyDetailsVC: UIViewController {
    
...

    let isConnected = Notification.Name(rawValue: isConnectedNotificationKey)
    let isNotConnected = Notification.Name(rawValue: isDisconnectedNotificationKey)
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        configureNavigationBar()
        
        addSubViews()
        
        activateConstraints()
        
        createObservers()
        
        fetchCompanyDetails(symbol: symbol)
        
        let controller = navigationController?.viewControllers.first as! CompanyPriceListVC
        controller.delegate = self

    }
    
    deinit {
        NotificationCenter.default.removeObserver(self)
    }
    
    private func createObservers() {
        NotificationCenter.default.addObserver(self, selector: #selector(CompanyDetailsVC.dismissAndFetchCompanyDetails), name: isConnected, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(CompanyDetailsVC.notifyUserOnScreen(notification:)), name: isNotConnected, object: nil)
    }
    
    @objc private func dismissAndFetchCompanyDetails() {
        print("DEBUG: dismissAndFetchCompanyDetails() called")
        if presentedViewController == alertController {
            self.alertController.dismiss(animated: true, completion: nil)
        }
        
        fetchCompanyDetails(symbol: symbol)
    }

    @objc private func notifyUserOnScreen(notification: NSNotification) {
        print("DEBUG: notifyUserOnScreen(notification) called")
        self.present(alertController, animated: true)
    }
...
    
}

extension CompanyDetailsVC: CompanyPriceListDelegate {
    func sendPriceHistory(_ priceHistory: PriceHistory) {
        self.updatePrices(priceHistory)
    }
}

I'm testing on a real device.

Answer 1

Removed socket.connect() from the.cancelled case