[Add gradient layer to view]

gradientLayerToView.swift

private let gradientLayer = CAGradientLayer()

override func layoutSubviews() {
    super.layoutSubviews()
    super.layoutIfNeeded()

    if let viewBounds = self.gradientView?.bounds {
        self.gradientLayer.frame = viewBounds
    }
}

private func addGradientBackground() {
    self.gradientView?.addGradientMask(
        gradientLayer: self.gradientLayer,
        colours: [UIColor.clear.cgColor, UIColor.white.cgColor],
        isVertical: true
    )
}