Programmatically create stack view - swift

Question

I am trying to create a date component by using a stack view programmatically. If user enters wrong date an error label will display message accordingly.Its working fine if I create it through storyboard, but when I use my programmatically created component which has added all elements in a stack view. I am not able to see error label.
I verified the autolayout I've added in storyboard and in my component class, both look similar. Here is code for my component.
class CustomDateView: UIView {
// MARK: - Variable
private let dayTextField: UITextField = {
let inputField = UITextField()
inputField.borderStyle = .none
inputField.layer.cornerRadius = 8.0
inputField.layer.borderColor = UIColor.darkGray.cgColor
inputField.backgroundColor = UIColor.blue
inputField.textAlignment = .center
inputField.tag = 0
inputField.translatesAutoresizingMaskIntoConstraints = false
return inputField
}()
private let monthTextField: UITextField = {
let inputField = UITextField()
inputField.borderStyle = .none
inputField.layer.cornerRadius = 8.0
inputField.layer.borderColor = UIColor.darkGray.cgColor
inputField.backgroundColor = UIColor.blue
inputField.textAlignment = .center
inputField.tag = 1
inputField.translatesAutoresizingMaskIntoConstraints = false
return inputField
}()
private let yearTextField: UITextField = {
let inputField = UITextField()
inputField.borderStyle = .none
inputField.layer.cornerRadius = 8.0
inputField.layer.borderColor = UIColor.darkGray.cgColor
inputField.backgroundColor = UIColor.blue
inputField.textAlignment = .center
inputField.tag = 2
inputField.translatesAutoresizingMaskIntoConstraints = false
return inputField
}()
private let errorLabel: UILabel = {
let errorLabel = UILabel()
errorLabel.textColor = .red
errorLabel.textAlignment = .center
errorLabel.numberOfLines = 0
errorLabel.translatesAutoresizingMaskIntoConstraints = false
return errorLabel
}()
private let monthSeparator: UILabel = {
let label = UILabel()
label.textAlignment = .center
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
private let yearSeparator: UILabel = {
let label = UILabel()
label.textAlignment = .center
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
private let horizontalStackView: UIStackView = {
let stackView = UIStackView()
stackView.axis = .horizontal
stackView.alignment = .fill
stackView.distribution = .fillProportionally
stackView.spacing = 16.0
stackView.translatesAutoresizingMaskIntoConstraints = false
return stackView
}()
private let verticalStackView: UIStackView = {
let stackView = UIStackView()
stackView.axis = .vertical
stackView.alignment = .fill
stackView.distribution = .fillProportionally
stackView.spacing = 8.0
stackView.translatesAutoresizingMaskIntoConstraints = false
return stackView
}()
// MARK: - Initialisers
override init(frame: CGRect) {
super.init(frame: frame)
self.setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.setup()
}
// MARK: - Private Functions
private func setup() {
self.horizontalStackView.addArrangedSubview(self.dayTextField)
self.horizontalStackView.addArrangedSubview(self.monthSeparator)
self.horizontalStackView.addArrangedSubview(self.monthTextField)
self.horizontalStackView.addArrangedSubview(self.yearSeparator)
self.horizontalStackView.addArrangedSubview(self.yearTextField)
self.verticalStackView.addArrangedSubview(self.horizontalStackView)
self.verticalStackView.addArrangedSubview(self.errorLabel)
self.addSubview(self.verticalStackView)
self.translatesAutoresizingMaskIntoConstraints = false
let selfType = type(of: self)
NSLayoutConstraint.activate([
self.dayTextField.heightAnchor.constraint(equalToConstant: 48.0),
self.dayTextField.widthAnchor.constraint(equalToConstant: 62.0),
self.monthTextField.widthAnchor.constraint(equalToConstant: 62.0),
self.monthSeparator.widthAnchor.constraint(equalToConstant: 14.0),
self.yearSeparator.widthAnchor.constraint(equalToConstant: 14.0)
])
NSLayoutConstraint.activate([
self.verticalStackView.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 0.0),
self.verticalStackView.topAnchor.constraint(equalTo: self.topAnchor, constant: 0.0),
self.bottomAnchor.constraint(equalTo: self.verticalStackView.bottomAnchor),
self.trailingAnchor.constraint(equalTo: self.verticalStackView.trailingAnchor)
])
}
}
It render view correctly but after setting error label stack view won't grow to display the text.I have given fixed width to my separators and textfield's cause I want them to be of that exact width and height.
Is there any mistakes I'm making while applying autolayout in here.