How do I use this code in a singleton in swift? - ios

Question

I have this code that I found here. Now I would like to know how to use it in a singleton. My understanding is if I use this code in a singleton I will be noticed if there is a change in the network status.
func startNetworkReachabilityObserver() {
let reachabilityManager = Alamofire.NetworkReachabilityManager(host: "www.google.com")
reachabilityManager?.listener = { status in
switch status {
case .NotReachable:
print("The network is not reachable")
case .Unknown :
print("It is unknown whether the network is reachable")
case .Reachable(.EthernetOrWiFi):
print("The network is reachable over the WiFi connection")
case .Reachable(.WWAN):
print("The network is reachable over the WWAN connection")
}
}
// start listening
reachabilityManager?.startListening()
}

Answer 1

Using a singleton is working as I long as you keep a reference of reachabilityManager
class NetworkStatus {
static let sharedInstance = NetworkStatus()
private init() {}
let reachabilityManager = Alamofire.NetworkReachabilityManager(host: "www.apple.com")
func startNetworkReachabilityObserver() {
reachabilityManager?.listener = { status in
switch status {
case .notReachable:
print("The network is not reachable")
case .unknown :
print("It is unknown whether the network is reachable")
case .reachable(.ethernetOrWiFi):
print("The network is reachable over the WiFi connection")
case .reachable(.wwan):
print("The network is reachable over the WWAN connection")
}
}
reachabilityManager?.startListening()
}
}
So you can use it like this:
let networkStatus = NetworkStatus.sharedInstance
override func awakeFromNib() {
super.awakeFromNib()
networkStatus.startNetworkReachabilityObserver()
}
You will be notified of any change in your network status.

Answer 2

Hoist the variable into the class as a property. Add a static shared property to make your class a singleton.
class ReachabilityManager {
private let networkReachabilityManager = NetworkReachabilityManager()
static let shared = ReachabilityManager()
private override init () {
super.init()
networkReachabilityManager?.listener = { status in
//Post Notifications here
}
}
}
func startListening() {
networkReachabilityManager.startListening()
}
}
The static properties are lazy by default so when you call ReachabilityManager.shared.startListening() it will instantiate the singleton the first time and subsequent calls use the existing shared instance.