iOS 7 ushered in the era of flat design. It also ushered in one major design flaw. Buttons do not look like buttons.

Text that is a button requires visual affordance that it can be tapped as opposed to text that is purely a label. The way that I style buttons is by adding a border with rounded corners. I feel this adds the required affordance while still staying true the minimal, flat design of the rest of the operating system.

I lay out views in Interface Builder. It is not possible to set the border out of the box. However, we can use @IBInspectable to help us.

// UIView+Inspectable.swift

extension UIView {
    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }
    
    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }
    
    @IBInspectable var borderColor: UIColor? {
        get {
            guard let borderColor = layer.borderColor else {
                return nil
            }
            return UIColor(cgColor: borderColor)
        }
        set {
            layer.borderColor = newValue?.cgColor
        }
    }
}

After we add this file to our Xcode project we are able to set these values in the Attribute Inspector.

Attribute Inspector