UIView loses constrains when animated - ios

Question

I'm trying to imitate the controller push transition but for views. But it loses constrains the moment I add the constrains of the new view even before the animation occurs. For a reproduction of issue scroll to the gif at the bottom.
Here's a snippet of the relevant prosperities: (the rest is merely a bunch of labels and buttons)
//MARK: Properities
var credential: AuthCredential!
let user = Auth.auth().currentUser
var userAuthenticated = false
let controllerTitle = "Update Email"
private var timer: Timer?
lazy var credentialVerificationView: UIView = {
let centerView = UIView()
centerView.frame.size.height = self.view.frame.height
centerView.frame.size.width = self.view.frame.width
centerView.backgroundColor = UIColor(named: "blankSlate")
return centerView
}()
lazy var emailUpdateView: UIView = {
let centerView = UIView()
centerView.frame.size.height = self.view.frame.height
centerView.frame.size.width = self.view.frame.width
centerView.backgroundColor = UIColor.red
return centerView
}()
I'm using transform to move the current view from the middle of the screen to -view.frame.width and the second view from -view.frame.width to the middle of the screen. func is:
private func startAutoScrollCardsCollectionView() {
/// This method start timer and fire it immediately
timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { [unowned self] _ in
UIView.animate(withDuration: 1) {
self.credentialVerificationView.transform = CGAffineTransform(translationX: -view.frame.width, y: 0)
self.emailUpdateView.transform = CGAffineTransform(translationX: -view.frame.width, y: 0)
}
}
}
And this is the ugly bit:
//MARK: authenticateUserAndConfigureView
/// the purpose of this func is merely sentimental; as long as its there it stops me from ever writing UI ever again
func authenticateUserAndConfigureView() {
// title = controllerTitle
view.backgroundColor = UIColor(named: "blankSlate")
emailTextField.textContentType = .username
emailTextField.keyboardType = .emailAddress
emailTextField.autocorrectionType = .no
emailTextField.autocapitalizationType = .none
emailTextField.spellCheckingType = .no
print("userAuthenticated = \(userAuthenticated)")
if userAuthenticated == true {
loginToContinueLabel.text = "Update Email"
infoLabel.text = currentEmailLabel1.text
errorLabel.text?.removeAll()
startAutoScrollCardsCollectionView()
emailUpdateView.addSubview(loginToContinueLabel)
loginToContinueLabel.anchor(top: emailUpdateView.topAnchor,
left: nil, bottom: nil,
right: nil,
paddingTop: 200,
paddingLeft: 0,
paddingBottom: 0,
paddingRight: 0,
width: 300, height: 50)
loginToContinueLabel.centerXAnchor.constraint(equalTo: emailUpdateView.centerXAnchor).isActive = true
emailUpdateView.addSubview(infoLabel)
infoLabel.anchor(top: loginToContinueLabel.bottomAnchor,
left: emailUpdateView.leftAnchor,
bottom: nil,
right: emailUpdateView.rightAnchor,
paddingTop: 24,
paddingLeft: 32,
paddingBottom: 0,
paddingRight: 32,
width: 0, height: 50)
infoLabel.centerXAnchor.constraint(equalTo: emailUpdateView.centerXAnchor).isActive = true
emailUpdateView.addSubview(emailContainerView)
emailContainerView.anchor(top: infoLabel.bottomAnchor,
left: emailUpdateView.leftAnchor,
bottom: nil,
right: emailUpdateView.rightAnchor,
paddingTop: 15,
paddingLeft: 32,
paddingBottom: 0,
paddingRight: 32,
width: 0, height: 50)
emailUpdateView.centerXAnchor.constraint(equalTo: emailUpdateView.centerXAnchor).isActive = true
emailUpdateView.addSubview(verifyLabel)
verifyLabel.anchor(top: emailContainerView.bottomAnchor,
left: emailUpdateView.leftAnchor,
bottom: nil,
right: emailUpdateView.rightAnchor,
paddingTop: 2,
paddingLeft: 32,
paddingBottom: 0,
paddingRight: 32,
width: 0, height: 20)
emailUpdateView.centerXAnchor.constraint(equalTo: emailUpdateView.centerXAnchor).isActive = true
emailUpdateView.addSubview(errorLabel)
errorLabel.anchor(top: verifyLabel.bottomAnchor,
left: nil,
bottom: nil,
right: nil,
paddingTop: 1,
paddingLeft: 0,
paddingBottom: 0,
paddingRight: 0,
width: 0, height: 0)
errorLabel.centerXAnchor.constraint(equalTo: emailUpdateView.centerXAnchor).isActive = true
emailUpdateView.addSubview(updateEmailButton)
updateEmailButton.anchor(top: errorLabel.bottomAnchor,
left: emailUpdateView.leftAnchor,
bottom: nil,
right: emailUpdateView.rightAnchor,
paddingTop: 16,
paddingLeft: 32,
paddingBottom: 0,
paddingRight: 32,
width: 0, height: 50)
updateEmailButton.centerXAnchor.constraint(equalTo: emailUpdateView.centerXAnchor).isActive = true
view.addSubview(emailUpdateView)
emailUpdateView.anchor(top: nil,
left: view.leftAnchor,
bottom: nil,
right: view.rightAnchor,
paddingTop: 0,
paddingLeft: +view.frame.width,
paddingBottom: 0,
paddingRight: -view.frame.width,
width: view.frame.width,
height: 0)
} else {
credentialVerificationView.addSubview(loginToContinueLabel)
loginToContinueLabel.anchor(top: credentialVerificationView.topAnchor,
left: nil, bottom: nil,
right: nil,
paddingTop: 200,
paddingLeft: 0,
paddingBottom: 0,
paddingRight: 0,
width: 300, height: 50)
loginToContinueLabel.centerXAnchor.constraint(equalTo: credentialVerificationView.centerXAnchor).isActive = true
credentialVerificationView.addSubview(infoLabel)
infoLabel.anchor(top: loginToContinueLabel.bottomAnchor,
left: credentialVerificationView.leftAnchor,
bottom: nil,
right: credentialVerificationView.rightAnchor,
paddingTop: 24,
paddingLeft: 32,
paddingBottom: 0,
paddingRight: 32,
width: 0, height: 50)
infoLabel.centerXAnchor.constraint(equalTo: credentialVerificationView.centerXAnchor).isActive = true
credentialVerificationView.addSubview(passwordContainerView)
passwordContainerView.anchor(top: infoLabel.bottomAnchor,
left: credentialVerificationView.leftAnchor,
bottom: nil,
right: credentialVerificationView.rightAnchor,
paddingTop: 16,
paddingLeft: 32,
paddingBottom: 0,
paddingRight: 32,
width: 0, height: 50)
passwordContainerView.centerXAnchor.constraint(equalTo: credentialVerificationView.centerXAnchor).isActive = true
credentialVerificationView.addSubview(loginButton)
loginButton.anchor(top: passwordContainerView.bottomAnchor,
left: credentialVerificationView.leftAnchor,
bottom: nil, right:
credentialVerificationView.rightAnchor,
paddingTop: 24,
paddingLeft: 32,
paddingBottom: 0,
paddingRight: 32,
width: 0, height: 50)
loginButton.centerXAnchor.constraint(equalTo: credentialVerificationView.centerXAnchor).isActive = true
credentialVerificationView.addSubview(needHelpButton)
needHelpButton.anchor(top: loginButton.bottomAnchor,
left: loginButton.leftAnchor,
bottom: nil,
right: nil,
paddingTop: 0,
paddingLeft: 0,
paddingBottom: 0,
paddingRight: 0,
width: 0, height: 0)
credentialVerificationView.addSubview(errorLabel)
errorLabel.anchor(top: needHelpButton.bottomAnchor,
left: credentialVerificationView.leftAnchor,
bottom: nil,
right: credentialVerificationView.rightAnchor,
paddingTop: 15,
paddingLeft: 32,
paddingBottom: 0,
paddingRight: 32,
width: 0, height: 0)
errorLabel.centerXAnchor.constraint(equalTo: credentialVerificationView.centerXAnchor).isActive = true
self.view.addSubview(credentialVerificationView)
credentialVerificationView.anchor(top: view.topAnchor,
left: view.leftAnchor,
bottom: view.bottomAnchor,
right: view.rightAnchor,
paddingTop: 0,
paddingLeft: 0,
paddingBottom: 0,
paddingRight: 0,
width: 0, height: 0)
credentialVerificationView.center = self.view.center
}
}
}