Extension on CALayer to add borders

CALayer+Borders.swift

extension CALayer {
    
    func addBorder(edge: UIRectEdge, color: UIColor, thickness: CGFloat, inset: CGFloat) {
        
        let border = CALayer()
        
        switch edge {
        case UIRectEdge.top:
            border.frame = CGRect.init(x: inset, y: 0, width: frame.width - inset * 2, height: thickness)
            border.name = "top"
        case UIRectEdge.bottom:
            border.frame = CGRect.init(x: inset, y: frame.height - thickness, width: frame.width - inset * 2, height: thickness)
            border.name = "bottom"
        case UIRectEdge.left:
            border.frame = CGRect.init(x: 0, y: 0, width: thickness, height: frame.height)
            border.name = "left"
        case UIRectEdge.right:
            border.frame = CGRect.init(x: frame.width - thickness, y: 0, width: thickness, height: frame.height)
            border.name = "right"
        default:
            break
        }
        border.backgroundColor = color.cgColor
        
        self.addSublayer(border)
    }
    
    func addAllBorders(color: UIColor, thickness: CGFloat) {
        addBorder(edge: .top, color: color, thickness: thickness, inset: 0)
        addBorder(edge: .bottom, color: color, thickness: thickness, inset: 0)
        addBorder(edge: .left, color: color, thickness: thickness, inset: 0)
        addBorder(edge: .right, color: color, thickness: thickness, inset: 0)
    }
    
    func removeBorders() {
        for layer in sublayers! {
            if layer.name == "top" || layer.name == "bottom" || layer.name == "left" || layer.name == "right" {
                layer.removeFromSuperlayer()
            }
        }
    }
}