Detect when iPhone is being unplugged and plugged in - swift

Question

I am just trying to write simple code that detects when the iPhone is unplugged and then plugged in. But being event-driven, instead of using a while loop. This code does work, but doesn't detect if the phone is unplugged and will not update the printed text.
EDIT
In the long run I just want the phone to play a sound whenever the iPhone is unplugged. (Sorry for leaving the end goal out.). I was using this print statements just so I can make sure it was working.
func startCharger()
{
printscreen.text="Started charger protocol"
UIDevice.current.isBatteryMonitoringEnabled=true
if(UIDevice.current.batteryState == .unplugged)
{
printscreen.text="Battery is unplugged"
}
else
{
printscreen.text="Battery is plugged in"
}
}

Answer 1

Quick implementation of Dule' code.
Check if the power is connected.
Copy these functions into your class.
Call isPowerConnected() in the viewDidLoad
func isPowerConnected(){
UIDevice.current.isBatteryMonitoringEnabled = true
NotificationCenter.default.addObserver(
self,
selector: #selector(batteryStateChanged),
name: .UIDeviceBatteryStateDidChange,
object: nil)
}
var chargingVar = "" //Empty Variable
func batteryStateChanged(){
if (UIDevice.current.batteryState == .charging) { //Here we check if the device is charging
UIApplication.shared.isIdleTimerDisabled = true //Here we disable the lock screen time out value
self.chargingVar = "is charging. \u{1F603}" //Here we change the variable to "is charging" 😀
chargingAlaer() //If power is pluged in we send an Alert
}else{
self.chargingVar = "is not charging. \u{1F622} " //Here we change the variable to "is not charging" 😥
chargingAlaer() //If power is not pluged we send an Alert
}
}
func chargingAlaer(){
let alertController = UIAlertController(title: "Charging Status",
message: "Your device \(chargingVar)",
preferredStyle: UIAlertControllerStyle.alert)
let ok = UIAlertAction(title: "OK",
style: UIAlertActionStyle.default,
handler: {(action) -> Void in
})
alertController.addAction(ok)
self.present(alertController, animated: true, completion: nil)
}

Answer 2

You can get a notification on battery state change with UIDeviceBatteryStateDidChange, the code looking something like this:
NotificationCenter.default.addObserver(
self,
selector: #selector(batteryStateChanged),
name: .UIDeviceBatteryStateDidChange,
object: nil)
Of course, you need a method in ViewController (or wherever you want to get notification). In this example:
func batteryStateChanged(){
// Your logic
}