Make a service call at regular interval of time in swift

Question

I am new to swift programming and I don't know how to call a method at regular interval of time. I have a demo app for service call but i don't know how can i call it at regular interval of time.

Answer 1

You can create an object of NSTimer() and call a function on definite time interval like this:

var updateTimer = NSTimer.scheduledTimerWithTimeInterval(15.0, target: self, selector: "callFunction", userInfo: nil, repeats: true)

this will call callFunction() every 15 sec.

func callFunction(){
    print("function called")
}

Answer 2

Here is a simple example with start and stop functions:

private let kTimeoutInSeconds:NSTimeInterval = 60

private var timer: NSTimer?

func startFetching() {
  self.timer = NSTimer.scheduledTimerWithTimeInterval(kTimeoutInSeconds,
    target:self,
    selector:Selector("fetch"),
    userInfo:nil,
    repeats:true)
}

func stopFetching() {
  self.timer!.invalidate()
}

func fetch() {
  println("Fetch called!")
}

If you get an unrecognized selector exception, make sure your class inherits from NSObject or else the timer's selector won't find the function!