Swift 4 - How to update progressView in loop - ios

Question

I have created this progressView:
progress = UIProgressView(progressViewStyle: .default)
progress.center = view.center
progress.setProgress(0.5, animated: true)
view.addSubview(progress)
In my viewDidLoad method, I call getLandGradingImages and inside that I do a loop, inside that I call getLandGradingImage for each result in getLandGradingImages, what would be the best way to update the progressView I created during this entire process:
getLandGradingImages(jobNo: jobNo) { result in
//Define axis variables
var x = 25
var y = 80
//Define image counter variable
var counterImages = 0
var actualImageCounter = 0
//For each Lot Image
for item in result
{
self.getLandGradingImage(image: item["imageBytes"] as! String) { data in
//Create Image from Data
let image = UIImage(data: data)
//Add Image to Image View
let imageView = UIImageView(image: image!)
//Set Image View Frame
imageView.frame = CGRect(x: x, y: y, width: 100, height: 100)
//Define UITapGestureRecognizer
let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.imageTapped(tapGestureRecognizer:)))
//Enable user interaction
imageView.isUserInteractionEnabled = true
//Assign tap gesture to image view
imageView.addGestureRecognizer(tapGestureRecognizer)
//Add Image to view
self.view.addSubview(imageView)
//Increase x axis
x = x + 115
//Increase image counter
counterImages = counterImages + 1
actualImageCounter = actualImageCounter + 1
//If image counter is equal to 3, create new line.
if(counterImages == 3)
{
//Increase y axis
y = y + 115
//Reset x axis
x = 25
//Reset image counter
counterImages = 0
}
if(actualImageCounter == result.count)
{
//self.stopIndicator()
}
}
}
}
Here are those two methods I am calling in this process:
func getLandGradingImages(jobNo:String, completionHandler:#escaping (_ result:Array<Dictionary<String, Any>>) -> Void) {
//Define array for returning data
var returnedResults = Array<Dictionary<String, Any>>()
//Call API
WebService().GetLandGradingImages(jobNo: jobNo)
{
(result: Array<Dictionary<String, Any>>) in
DispatchQueue.main.async {
//Return our results
returnedResults = result
completionHandler(returnedResults)
}
}
}
func getLandGradingImage(image:String, completionHandler:#escaping (_ result:Data) -> Void) {
//Define array for returning data
var returnedResults = Data()
//Call API
WebService().GetLandGradingImage(image: image)
{
(result: Data) in
DispatchQueue.main.async {
//Return our results
returnedResults = result
completionHandler(returnedResults)
}
}
}
For these calls, I am using Alamofire:
func GetLandGradingImage(image: String, completion: #escaping (_ result: Data) -> Void)
{
let imagePath : String = image
let url = URL(string: webserviceImages + imagePath)!
Alamofire.request(url).authenticate(user: self.appDelegate.username!, password: self.appDelegate.password!).responseData { response in
let noData = Data()
if(response.error == nil)
{
if let data = response.data {
completion(data)
}
}
else
{
completion(noData)
}
}
}
I have tried this:
var counter:Int = 0 {
didSet {
let fractionalProgress = Float(counter) / 100.0
let animated = counter != 0
progress.setProgress(fractionalProgress, animated: animated)
}
}
and inside the for loop:
DispatchQueue.global(qos: .background).async {
sleep(1)
DispatchQueue.main.async {
self.counter = self.counter + 1
}
}
Still nothing, my the progress view appears but does not get updated.