Simple custom image view to load image asynchronously

UIAsyncImageView-NSCache.swift

class UIAsyncImageView: UIImageView {
    static let imageCache = NSCache<AnyObject, AnyObject>()
    
    // Associated Object property; implementation omitted.
    final private var imageUrl: URL?

    func loadImage(from urlString: String, placeholder: UIImage? = nil) {
        setImage(placeholder)

        guard let url = URL(string: urlString) else {
            return
        }

        imageUrl = url

        if let cachedImage = UIAsyncImageView.imageCache.object(forKey: url as AnyObject) as? UIImage {
            self.setImage(cachedImage)
            return
        }

        APIService().get(url: url) { [weak self] (data, error) in
            guard let _imageUrl = self?.imageUrl, _imageUrl == url else {
                return
            }

            guard let data = data, let image = UIImage(data: data) else {
                return
            }

            self?.setImage(image)
            UIAsyncImageView.imageCache.setObject(image, forKey: url as AnyObject)
        }
    }

    private func setImage(_ image: UIImage?) {
        DispatchQueue.main.async { [weak self] in
            self?.image = image
        }
    }
}