CollectionViewCell.swift

import UIKit
import Parse

class HomeWorkoutCollectionViewCell: UICollectionViewCell {

    @IBOutlet weak var nameLabel: UILabel!
    @IBOutlet weak var focusLabel: UILabel!
    @IBOutlet weak var durationLabel: UILabel!
    @IBOutlet weak var coverImage: UIImageView!
    
    
    var viewModel: HomeWorkoutCellViewModel? {
        didSet {
            bindViewModel()
        }
    }
    
    private func bindViewModel() {
        self.nameLabel?.text = viewModel?.name
        self.focusLabel?.text = viewModel?.focus
        self.durationLabel?.text = viewModel?.durationText
        
        DispatchQueue.global(qos: .userInteractive).async { [weak self] in
            // Async background process
            if let imageFile : PFFile = self?.viewModel?.cover {
                imageFile.getDataInBackground(block: { (data, error) in
                    if error == nil {
                        DispatchQueue.main.async {
                            // Async main thread
                            let image = UIImage(data: data!)
                            self?.coverImage.image = image
                        }
                    } else {
                        print(error!.localizedDescription)
                    }
                })
            }
        }
    }
}