Swift: Run func every minutes - swift

Question

I'm working in swift and want to run a function every minute. I want to update a label with a count down timer with how many minutes left till the next update.
I have a basic version working
if let date = newDate {
let formatter : NSDateFormatter = NSDateFormatter()
formatter.dateFormat = "HH:mm"
formatter.timeZone = NSTimeZone.defaultTimeZone()
let string : NSString = formatter.stringFromDate(date)
let calendar = NSCalendar.currentCalendar()
let comp = calendar.components([.Minute], fromDate: date)
let minute = comp.minute
let remaining : Int = 60 - minute
var mins = "s"
if remaining == 1 {
mins = ""
}
self.refreshInLabel.text = "Refreshes at \(string) - \n \(remaining) minute\(mins) remaining "
}
which is updating when i view the page on the app, but i want it to auto update every minutes.
I've looked at NSTimer, i believe it can be done with this (as shown here: How to make a countdown with NSTimer on Swift) but i can't work out how to make it fire on the minute, only after a certain time display
Edit:
I have the following so far
override func viewDidLoad() {
super.viewDidLoad()
let calendar = NSCalendar.currentCalendar()
let comp = calendar.components([.Minute], fromDate: NSDate())
minute = comp.minute
_ = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: #selector(AdoptionCentreVC.updateTimer), userInfo: nil, repeats: true)
}
func updateTimer() {
let calendar = NSCalendar.currentCalendar()
let comp = calendar.components([.Minute], fromDate: NSDate())
let curMin = comp.minute
if(curMin > minute) {
NSLog("Changed")
self.minute = curMin
}
}
I'd like to know if theres a better way

Answer 1

What I suggest you is to fire a NSNotification when you want to start your func every minute.
When you receive your NSNotification call a function like this :
var yourTimer = NSTimer()
func callWhenNotificationReceived(){
yourFuncToFire()
yourTimer = NSTimer.scheduledTimerWithTimeInterval(60, target: self, selector: #selector(YourViewController.yourFuncToFire) , userInfo: nil, repeats: true)
}

Answer 2

var TotalTime:Int = 0
var timer: NSTimer?
triggerCountDownTimerFor(time:Int)
func triggerCountDownTimerFor(time:Int)
{
totalTime = time
timer = NSTimer.scheduledTimerWithTimeInterval(1, target:self, selector: #selector(LoginViewController.updateTimer), userInfo: nil, repeats: true)
}
func updateTimer()
{
let date = NSDate()
let formatter : NSDateFormatter = NSDateFormatter()
formatter.dateFormat = "HH:mm"
formatter.timeZone = NSTimeZone.defaultTimeZone()
let string : NSString = formatter.stringFromDate(date)
let calendar = NSCalendar.currentCalendar()
let comp = calendar.components([.Minute], fromDate: date)
let minute = comp.minute
let remaining : Int = TotalTime - minute
var mins = "s"
if remaining == 1 {
mins = ""
}
print("Refreshes at \(string) - \n \(remaining) minute\(mins) remaining ")
}