Swift: How to increment an element in an array - ios

Question

I am trying to display different text within a label after a period of time using a timer, but cant increment the element of my custom type array.
Here is the code:
import UIKit
class WorkWorkoutViewOne: UIViewController {
#IBOutlet weak var exerciseTitle: UILabel!
#IBOutlet weak var timerLabel: UILabel!
#IBOutlet weak var instructionsLabel: UILabel!
#IBOutlet weak var exerciseImage: UIImageView!
var counter = 15
var timer: NSTimer?
var workoutExercisesShuffled = [Exercise]()
override func viewDidLoad() {
super.viewDidLoad()
let image: UIImage = workoutExercisesShuffled[0].filename!
exerciseImage.image = image
let titleLabel = workoutExercisesShuffled[0].name
exerciseTitle.text = titleLabel
let instructionsTitle = workoutExercisesShuffled[0].instructions
instructionsLabel.text = instructionsTitle
var timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "timerAction", userInfo: nil, repeats: true)
}
var timerTwo: NSTimer?
var counterTwo = 15
func timerAction() {
--counter
timerLabel.text = "\(counter)"
if (counter == 0) {
timer?.invalidate()
let image: UIImage = workoutExercisesShuffled[1].filename!
exerciseImage.image = image
let titleLabel = workoutExercisesShuffled[1].name
exerciseTitle.text = titleLabel
let instructionsTitle = workoutExercisesShuffled[1].instructions
instructionsLabel.text = instructionsTitle
timerLabel.text = "\(counterTwo)"
var timerTwo = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "timerActionTwo", userInfo: nil, repeats: true)
}
}
Repeating this method using timerThree, timerFour etc. seems clumbsy and unnecessary, so would like a way to increment the array values rather than having to call seperately in different functions.

Answer 1

Try this, it uses two methods and an index.
Workflow
Initially index is set to 0 and counter is set to 15.
updateExercise() is called.
The exercise UI is updated.
If index is 0 the timer is created.
timerAction() is called after the timer fires.
The counter is decremented and the counter label is updated.
If counter is 0 and index is equal to the number of exercises -1 the timer is invalidated.
If counter is 0 and index < number of exercises -1 index is incremented, counter is reset to 15 and updateExercise() is called again.
var counter = 15
var index = 0
var timer: NSTimer?
var workoutExercisesShuffled = [Exercise]()
override func viewDidLoad() {
super.viewDidLoad()
updateExercise()
}
func updateExercise() {
let image: UIImage = workoutExercisesShuffled[index].filename!
exerciseImage.image = image
let titleLabel = workoutExercisesShuffled[index].name
exerciseTitle.text = titleLabel
let instructionsTitle = workoutExercisesShuffled[index].instructions
instructionsLabel.text = instructionsTitle
if index == 0 {
timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "timerAction", userInfo: nil, repeats: true)
}
}
func timerAction() {
counter -= 1
timerLabel.text = "\(counter)"
if (counter == 0) {
if index == workoutExercisesShuffled.count - 1 {
timer!.invalidate()
timer = nil
} else {
index += 1
counter = 15
updateExercise()
}
}
}

Answer 2

I did not test this, but it should work.
import UIKit
class WorkWorkoutViewOne: UIViewController {
#IBOutlet weak var exerciseTitle: UILabel!
#IBOutlet weak var timerLabel: UILabel!
#IBOutlet weak var instructionsLabel: UILabel!
#IBOutlet weak var exerciseImage: UIImageView!
var count = 15
var index = 0
var timer: NSTimer
var countdown: NSTimer
var workoutExercisesShuffled = [Exercise]()
override func viewDidLoad() {
super.viewDidLoad()
// TODO: load your exercises
var timer = NSTimer.scheduledTimerWithTimeInterval(15, target: self, selector: "displayNewExercise", userInfo: nil, repeats: true)
}
func displayNewExercise() {
countdown = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "displayCountdown", userInfo: nil, repeats: true)
if (index < workoutExercisesShuffled.count) {
exerciseImage.image = workoutExercisesShuffled[index].filename!
exerciseTitle.text = workoutExercisesShuffled[index].name
instructionsLabel.text = workoutExercisesShuffled[index].instructions
++index
}
else {
timer.invalidate()
countdown.invalidate()
}
}
func displayCountdown() {
if(count > 0) {
countDownLabel.text = String(--count)
}
else {
countdown.invalidate()
count = 15
}
}
}
Don't repeat yourself. A certain task can be done only by one function, the code for this particular task must not be elsewhere.