swift gradient

class GradientView: UIView {
    
    var gradientLayer: CAGradientLayer?
    var colors: [UIColor] = []
    
    override func layoutSubviews() {
        super.layoutSubviews()
        createGradientLayer()
    }
    
    func createGradientLayer() {
        if gradientLayer == nil {
            gradientLayer = CAGradientLayer()
        }
        guard let gradientLayer = self.gradientLayer else { return }
        gradientLayer.frame = bounds
        gradientLayer.colors = colors.map({ $0.cgColor })
        layer.addSublayer(gradientLayer)
    }
}