Tracking upload progress in UICollectionView is duplicating cells - ios

Question

I have a following setup:
UploadedCell
DisplayUploadsVC
UploadHelper with delegate that tracks
progress (this is singleton)
In my controller I have a timer in cellForItemAt that gets the progress for uploadId that is currently uploading and update the cell upload item.
In my cell I use prepareForReuse and set my upload to nil.
But again when I scroll and cells reuse I see duplicate cells. I also see when I pullToRefress or go to the end of results to get more results from server.
Just not sure what I'm missing or if I can use this kind of implementation with timer in collection view cell to get the progress.
UploadedCell
class UploadedCell: UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
// MARK: Variables declaration
let uploadBadge = UIImageView(image: #imageLiteral(resourceName: "uploads") , contentMode: .scaleAspectFit)
let uploadName = UILabel(font: UIFont.openSansSemiboldFontOfSize(18))
let statusName = UILabel(font: UIFont.openSansSemiboldFontOfSize(18))
#objc lazy var moreButton: UIButton = {
let button = UIButton()
button.setImage(UIImage(named: "dots-menu")?.withRenderingMode(.alwaysTemplate), for: .normal)
button.tintColor = .lightGray
button.addTarget(self, action: #selector(handleMore), for: .touchDown)
return button
}()
// MARK - didSet
var upload: UploadModel.UploadItem? {
didSet {
uploadName.text = upload?.title
statusName.text = upload?.status
}
}
// MARK: - Main Init
override init(frame: CGRect) {
super.init(frame: frame)
backgroundColor = .white
setupViews()
}
override func prepareForReuse() {
self.upload = nil
super.prepareForReuse()
}
}
DisplayUploadsVC
class DisplayUploadsVC: UICollectionViewController, UICollectionViewDelegateFlowLayout {
// MARK: - Properties
/// various object init
var uploadCell: UploadCell = UploadCell()
var uploadProgress = (progress: Float(0), uploadId: "")
var progressTimer = Timer()
override func viewDidLoad() {
super.viewDidLoad()
UploadHelper.shared.uploadHelperDelegate = self
setupViews()
setupEmptyBackgroundView()
fetchUploads()
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! UploadCell
cell.upload = nil
var upload = isSearching ? filteredResults[indexPath.item] : results?[indexPath.item]
cell.upload = upload
// get uploads with paging if we are paginating
if (self.uploadProgress.uploadId == upload?.id && self.uploadProgress.progress < 99) {
progressTimer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { timer in
upload?.status = String(format: NSLocalizedString("Uploading %.0f%%", comment: ""), self.uploadProgress.progress)
cell.upload = upload
if self.uploadProgress.progress > 99.9 {
self.progressTimer.invalidate()
upload?.status = NSLocalizedString("Upload DONE", comment: "")
cell.upload = upload
}
}
}
return cell
}
extension DisplayUploadsVC : UploadHelperProgress {
func showProgress(progress: Float, uploadId: String) {
self.uploadProgress.progress = progress
self.uploadProgress.uploadId = uploadId
}
}
UploadHelper
protocol UploadHelperProgress : class {
func showProgress(progress: Float, uploadId: String)
}
private var id: String?
private let progressBlock = { bytesWritten, bytesTotal in
var progress = Float(bytesWritten) / Float(bytesTotal)
UploadHelper.shared.uploadHelperDelegate?.showProgress(progress: progress * 100, uploadId: id ?? "")
} as UploadProgressBlock
class UploadHelper: NSObject {
/// delegate
weak var uploadHelperDelegate: UploadHelperProgress?
/// singleton
static let shared = UploadHelper()
func upload(fileUrl: URL, fileUploadUrl: String, uploadId: String) {
id = uploadId
//
// upload logic
//
upload?.progressBlock = progressBlock
upload?.resume()
}
}