How to get notifications for Network change(Connect,Disconnect,Change) - ios

Question

In my app I have to alert whenever a network change happens for example when a app is connected or disconnected or changed(wifi to data) network.
But finding it by reaching a url seems expensive.
Is there any public api available in iOS to do this.

Answer 1

I followed this tutorial
https://www.youtube.com/watch?v=wDZmz9IsB-8
credit --> Vasil Nunev
Download this class and import to my project --> Reachability.swift
https://github.com/ashleymills/Reachability.swift
(Reachability.swift) --> Unzip -->Sources/Reachability.swift
This is my view controller
import UIKit
class ViewController: UIViewController {
let reachability = Reachability()!
override func viewDidLoad() {
super.viewDidLoad()
reachability.whenReachable = { _ in
DispatchQueue.main.async {
self.view.backgroundColor = UIColor.green
}
}
reachability.whenUnreachable = { _ in
DispatchQueue.main.async {
self.view.backgroundColor = UIColor.red
}
}
NotificationCenter.default.addObserver(self, selector: #selector(internetChanged), name: Notification.Name.reachabilityChanged , object: reachability)
do{
try reachability.startNotifier()
} catch {
print("Could not strat notifier")
}
}
#objc func internetChanged(note:Notification) {
let reachability = note.object as! Reachability
if reachability.isReachable{
if reachability.isReachableViaWiFi{
self.view.backgroundColor = UIColor.green
}
else{
DispatchQueue.main.async {
self.view.backgroundColor = UIColor.orange
}
}
} else{
DispatchQueue.main.async {
self.view.backgroundColor = UIColor.red
}
}
}
}

Answer 2

Look at this official Apple documentation
Using Reachability you can recognize the type of your connection.
There is also a complete example on how detect the changes and the documentation is updated now for ARC.
I hope this can help you

Answer 3

Possible help:
Reachability
Event notification for network activity

Answer 4

If you're using Alamofire in your application, you can use it's NetworkReachabilityManager.swift class to listen for network's connectivity.
This is the piece of code.
#discardableResult
open func startListening(onQueue queue: DispatchQueue = .main,
onUpdatePerforming listener: #escaping Listener) -> Bool {
stopListening()
$mutableState.write { state in
state.listenerQueue = queue
state.listener = listener
}
var context = SCNetworkReachabilityContext(version: 0,
info: Unmanaged.passUnretained(self).toOpaque(),
retain: nil,
release: nil,
copyDescription: nil)
let callback: SCNetworkReachabilityCallBack = { _, flags, info in
guard let info = info else { return }
let instance = Unmanaged<NetworkReachabilityManager>.fromOpaque(info).takeUnretainedValue()
instance.notifyListener(flags)
}
let queueAdded = SCNetworkReachabilitySetDispatchQueue(reachability, reachabilityQueue)
let callbackAdded = SCNetworkReachabilitySetCallback(reachability, callback, &context)
// Manually call listener to give initial state, since the framework may not.
if let currentFlags = flags {
reachabilityQueue.async {
self.notifyListener(currentFlags)
}
}
return callbackAdded && queueAdded
}
/// Stops listening for changes in network reachability status.
open func stopListening() {
SCNetworkReachabilitySetCallback(reachability, nil, nil)
SCNetworkReachabilitySetDispatchQueue(reachability, nil)
$mutableState.write { state in
state.listener = nil
state.listenerQueue = nil
state.previousStatus = nil
}
}
You can also use Apple's SCNetworkReachbility class instead.