Simple IBDesignable template for a UIView with customizable cornerRadius, strokeWidth and strokeColor.

RoundedView.swift

@IBDesignable
class RoundedView: UIView {

    @IBInspectable var roundedValue: CGFloat = 0.0 {
        didSet {
            layer.cornerRadius = roundedValue
        }
    }
    
    @IBInspectable var strokeWidth: CGFloat = 0.0 {
        didSet {
            layer.borderWidth = strokeWidth
        }
    }
    
    @IBInspectable var strokeColor: UIColor = UIColor.clear {
        didSet {
            layer.borderWidth = strokeWidth
            layer.borderColor = strokeColor.cgColor
        }
    }
}