Toggle Hidden and Height Constraint

gistfile1.txt

class ToggleHiddenLabel:UILabel {
    
    var heightConstraint:NSLayoutConstraint!
    var visible:Bool = false {
        didSet {
            if visible {
                self.removeConstraint(self.heightConstraint)
                self.hidden = false
            } else {
                self.addConstraint(self.heightConstraint)
                self.hidden = true
            }
        }
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        self.heightConstraint = NSLayoutConstraint(item: self, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 0, constant: 0)
        self.addConstraint(self.heightConstraint)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
}

// Usage

let label = ToggleHiddenLabel()
label.visible = false