indexPath.row not getting data from the array - ios

Question

I've created a PFQuery to get some strings from my parse server and the put this in a couple of arrays
var packsAvailable = [""]
var packsImage = [""]
var packsDescription = [""]
If I print the value of the array in the for loop of the query I get all the values in a proper array. However when I try and use this information to populate my collection view nothing happens. I can't figure this out because it works with the manually created arrays tableImages and tableData that I have commented out for testing.
import UIKit
import Parse
private let reuseIdentifier = "Cell"
class CollectionViewController: UICollectionViewController {
//var tableData: [String] = ["Tis is a description", "Test 22", "Test 33"]
//var tableImages: [String] = ["walk1bg", "2", "walk3bg"]
var packsAvailable = [""] // the total packs in the app
var packsImage = [""]
var packsDescription = [""]
override func viewDidLoad() {
super.viewDidLoad()
let packQuery = PFQuery(className: "Pack")
packQuery.findObjectsInBackground(block: { (objectsArray, error) in
if error != nil {
print(error!)
} else if let packs = objectsArray {
self.packsAvailable.removeAll() // remove them incase they double up
print(packs.count)
for object in packs {
/*
print(object["packName"])
print(object["packImage"])
print(object["packDesctription"])
*/
self.packsAvailable.append(object["packName"] as! String)
self.packsImage.append(object["packImage"] as! String)
self.packsDescription.append(object["packDesctription"] as! String)
/*
print(self.packsAvailable)
print(self.packsImage)
print(self.packsDescription)
*/
}
}
})
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
// MARK: UICollectionViewDataSource
override func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return packsAvailable.count
}
func UIColorFromHEX(hexValue: UInt) -> UIColor {
return UIColor(
red: CGFloat((hexValue & 0xFF0000) >> 16) / 255.0,
green: CGFloat((hexValue & 0x00FF00) >> 8) / 255.0,
blue: CGFloat(hexValue & 0x0000FF) / 255.0,
alpha: CGFloat(1.0)
)
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell: CollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath) as! CollectionViewCell
//cell.labelCell.text = tableData[indexPath.row]
//cell.imageCell.image = UIImage(named: tableImages[indexPath.row])
cell.labelCell.text = packsDescription[indexPath.row]
print(packsDescription[indexPath.row])
cell.imageCell.image = UIImage(named: packsImage[indexPath.row])
cell.imageCell.layer.masksToBounds = true
cell.imageCell.layer.cornerRadius = cell.imageCell.frame.height/2
cell.imageCell.layer.borderWidth = 3
cell.imageCell.layer.borderColor = UIColorFromHEX(hexValue: 0x62aca2).cgColor
return cell
}
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
print("Selected \(indexPath.row)")
}
}

Answer 1

add collectionView.reloadData() after the for-in loop is completed inside your closure. This will tell your collectionView to fetch the current array values.

Answer 2

You forgot to reload the collectionView when the response comes from the server. just add collectionView.reloadData() after completion of for loop
override func viewDidLoad() {
super.viewDidLoad()
let packQuery = PFQuery(className: "Pack")
packQuery.findObjectsInBackground(block: { (objectsArray, error) in
if error != nil {
print(error!)
} else if let packs = objectsArray {
self.packsAvailable.removeAll() // remove them incase they double up
print(packs.count)
for object in packs {
/*
print(object["packName"])
print(object["packImage"])
print(object["packDesctription"])
*/
self.packsAvailable.append(object["packName"] as! String)
self.packsImage.append(object["packImage"] as! String)
self.packsDescription.append(object["packDesctription"] as! String)
/*
print(self.packsAvailable)
print(self.packsImage)
print(self.packsDescription)
*/
}
//swift 2.3
dispatch_async(dispatch_get_main_queue()) {
self.collectionView.reloadData()
}
//swift 3
/* DispatchQueue.main.async {
self.collectionView.reloadData()
}*/
}
})
}