Running Pace Calculator in Swift - swift

Question

I'm a complete newbie to Swift. I have created a running pace calculator as experiment in Playground and it works perfectly, but I struggle to figure out how to connect it to a UI.
Things in particular I struggle with currently:
Casting a text string to an Int label
Does the function that does the calculation go in the IBAction?
Playground Code
import UIKit
func PaceCalculator (minutes:Double, seconds:Double, distance:Double) -> Double{
return ((minutes*60) + seconds) / distance
}
var paceInSeconds = PaceCalculator(28, 26, 10.1)
var paceInMinutes = paceInSeconds / 60
var roundedMinutes = Double(floor(paceInMinutes))
var decimalSeconds = paceInMinutes - roundedMinutes
var intPace = Int(floor(roundedMinutes))
var seconds = Int(floor(decimalSeconds * 60))
println("Your average pace is \(intPace):\(seconds)/km")
Incomplete Swift Code
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
#IBAction func calculatePaceButton(sender: UIButton) {
}
#IBOutlet weak var minutesTextField: UITextField!
#IBOutlet weak var distanceTextField: UITextField!
#IBOutlet weak var paceLabel: UILabel!
}
Storyboard
Disclaimer: I have no programming experience either. So be gentle on the jargon and explanation.)

Answer 1

Hope this will work for you :
You didn't added secondsTextField as IBOutlet please check that too.
class ViewController: UIViewController {
#IBOutlet weak var minutesTextField: UITextField!
#IBOutlet weak var distanceTextField: UITextField!
#IBOutlet weak var paceLabel: UILabel!
#IBOutlet weak var secondsTextField: UITextField!
#IBAction func calculatePaceButton(sender: UIButton) {
var paceInSeconds = PaceCalculator((minutesTextField.text as NSString).doubleValue, seconds: (secondsTextField.text as NSString).doubleValue, distance: (distanceTextField.text as NSString).doubleValue)
var paceInMinutes = paceInSeconds / 60.0
var roundedMinutes = Double(floor(paceInMinutes))
var decimalSeconds = paceInMinutes - roundedMinutes
var intPace = Int(floor(roundedMinutes))
var seconds = Int(floor(decimalSeconds * 60))
paceLabel.text = "\(intPace)"
}
func PaceCalculator (minutes:Double, seconds:Double, distance:Double) -> Double{
return ((minutes*60) + seconds) / distance
}
}

Answer 2

Here I would like to share my solution to calculate pace. The calculation is based on inputs of times and locations, which are more generic and useful.
typealias ShortFullTupleStrings = (short: String, full: String)
class PaceCalculator {
private static func relatedTimeString(
for value: TimeInterval)
-> ShortFullTupleStrings?
{
let fm = DateComponentsFormatter()
switch abs(value) {
case 0 ..< 24*3600: // within one day
fm.allowedUnits = [.year, .day, .hour, .minute, .second]
case 24*3600 ..< 24*3600*10: // within 1-10 days
fm.allowedUnits = [.year, .day, .hour, .minute]
case 24*3600*10 ..< 24*3600*365: // within 10-365 days
fm.allowedUnits = [.year, .day, .hour]
default: // within 365-1000 days
fm.allowedUnits = [.year, .day]
}
fm.unitsStyle = .short
let short = fm.string(from: value)
fm.unitsStyle = .full
let full = fm.string(from: value)
if let short = short, let full = full {
return (short, full)
} else {
return nil
}
}
static var isMetric: Bool {
let locale = NSLocale.current
let metricSystem = locale.usesMetricSystem
return metricSystem
}
static func paceFrom( _
dt1: Date, to dt2: Date,
distanceFrom loc1: CLLocation, to loc2: CLLocation) ->
ShortFullTupleStrings?
{
let timeInterval = dt2.timeIntervalSince(dt1)
let dist = loc2.distance(from: loc1)
let pace: ShortFullTupleStrings?
if !dist.isZero {
let paceV: TimeInterval
if isMetric {
paceV = timeInterval / (dist / 1000.0)
} else {
paceV = timeInterval / (dist / 1609.344)
}
pace = relatedTimeString(for: paceV)
} else {
pace = nil
}
return pace
}
}
relatedTimeString is a helper func to get a time string in the format of short form of # yrs, # days, # hrs, # min, # sec, and full form of # years, ..., depending on none zero values. For example, 6 min, 5 sec in short form, or 6 minutes, 5 seconds in full form.
In this way, the func is more generic and supports localization and accessibilities.