Appearance proxies / UI_APPEARANCE_SELECTOR in Swift?

Question

The Apple documentation states:

To participate in the appearance proxy API, tag your appearance property selectors in your header with UI_APPEARANCE

Answer 1

Based on previous answers, here is the extension to UIView I implemented to manage UIView appearance with view borders, I hope it can help someone :

extension UIView {
    @objc dynamic  var borderColor: UIColor? {
        get {
            if let color = self.layer.borderColor {
                return UIColor(cgColor: color)
            } else {
                return nil
            }
        }
        set(color) {
            self.layer.borderColor = color?.cgColor
        }
    }

    @objc dynamic  var borderWidth: NSNumber? {
        get { return NSNumber(value: Float(self.layer.borderWidth))}
        set(width) {
            self.layer.borderWidth = CGFloat(width?.floatValue ?? 0)
        }
    }

    @objc dynamic  var cornerRadius: NSNumber? {
        get { return NSNumber(value: Float(self.layer.cornerRadius))}
        set(radius) {
            self.layer.cornerRadius = CGFloat(radius?.floatValue ?? 0)
        }
    }
}