How to display 24 hour counter once button is pressed - ios

Question

Once my button is pressed I would like to disable my button for 24 hours and displaying a countdown on a label display a countdown until the button will be active again.
I have saved the waiting date and compared it to current date but I am not sure how to display the countdown of how much time is left in hours, minutes, and seconds.
let todaysDate = Date()
func set24HrTimer() {
let currentDate = Date()
let newDate = Date(timeInterval: 86400, since: currentDate as Date)
UserDefaults.standard.set(newDate, forKey: "waitingDate")
print("24 hours started")
//disable the button
}
if let waitingDate:Date = UserDefaults.standard.value(forKey: "waitingDate") as? Date {
if (todaysDate.compare(waitingDate as Date) == ComparisonResult.orderedDescending) {
print("show button")
}
else {
print("hide button")
}
}

Answer 1

You can add following code to create time countdown.
First add two variable ass follow:
fileprivate var timeWorking : Bool = false // To check is timer already scheduled
var timer:Timer? // Instance of timer
Then add following code which will calculate remaining hour, minute and second.
func timeLeftExtended(date:Date) ->NSAttributedString{
let cal = Calendar.current
let now = Date()
let calendarUnits:NSCalendar.Unit = [NSCalendar.Unit.hour, NSCalendar.Unit.minute, NSCalendar.Unit.second]
let components = (cal as NSCalendar).components(calendarUnits, from: now, to: date, options: [])
let fullCountDownStr = "\(components.hour!.description)h " + "\(components.minute!.description)m " + "\(components.second!.description)s "
let mutableStr = NSMutableAttributedString(string: fullCountDownStr, attributes: [NSAttributedString.Key.foregroundColor:UIColor.white])
for (index, char) in mutableStr.string.enumerated()
{
if(char == "h" || char == "m" || char == "s")
{
mutableStr.removeAttribute(NSAttributedString.Key.foregroundColor, range: NSMakeRange(index, 1))
mutableStr.addAttributes([NSAttributedString.Key.foregroundColor : UIColor.lightGray], range: NSMakeRange(index, 1))
}
}
return mutableStr
}
Next, add code which is scheduledTimer if not scheduled.
func setupTimer()
{
if(!timeWorking)
{
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.updateCountDown), userInfo: nil, repeats: true)
self.timeWorking = true
}
}
Add code to display count down in label.
#objc func updateCountDown()
{
if let waitingDate = UserDefaults.standard.value(forKey: "waitingDate") as? Date {
self.labelCountDown.attributedText = self.timeLeftExtended(date: waitingDate)
} else {
let newDate = Calendar.current.date(byAdding: .hour, value: 24, to: Date())
UserDefaults.standard.set(newDate, forKey: "waitingDate")
self.labelCountDown.attributedText = self.timeLeftExtended(date: newDate!)
}
}
Call setupTimer() method to continue timer.
Output: