AutoLayout.swift

extension UIView {
    
    func anchorToTop(top: NSLayoutYAxisAnchor? = nil, left: NSLayoutXAxisAnchor? = nil, bottom: NSLayoutYAxisAnchor? = nil, right: NSLayoutXAxisAnchor? = nil) {
        
        anchorWithConstantsToTop(top: top, left: left, bottom: bottom, right: right, topConstant: 0, leftConstant: 0, bottomConstant: 0, rightConstant: 0)
    }
    
    func anchorWithConstantsToTop(top: NSLayoutYAxisAnchor? = nil, left: NSLayoutXAxisAnchor? = nil, bottom: NSLayoutYAxisAnchor? = nil, right: NSLayoutXAxisAnchor? = nil, topConstant: CGFloat = 0, leftConstant: CGFloat = 0, bottomConstant: CGFloat = 0, rightConstant: CGFloat = 0) {
        
        translatesAutoresizingMaskIntoConstraints = false
        
        if let top = top {
            topAnchor.constraint(equalTo: top, constant: topConstant).isActive = true
        }
        
        if let bottom = bottom {
            bottomAnchor.constraint(equalTo: bottom, constant: -bottomConstant).isActive = true
        }
        
        if let left = left {
            leftAnchor.constraint(equalTo: left, constant: leftConstant).isActive = true
        }
        
        if let right = right {
            rightAnchor.constraint(equalTo: right, constant: -rightConstant).isActive = true
        }
        
    }
    
}