How to perform the Segue only after authorization with Touch ID - swift

Question

Maybe someone can help, just want to use Segue for Login button to made a transfer to second ViewController only after authorization with Touch ID but application still performing the Segue after user pressing on the button.
import UIKit
import LocalAuthentication
class LoginWindowViewController: UIViewController {
#IBAction func loginButton(_ sender: Any) {
let context: LAContext = LAContext()
if context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil){
context.evaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, localizedReason: "For login you need to use your TouchID", reply: {(wasSuccessful, error) in if wasSuccessful {
DispatchQueue.main.async {
self.shouldPerformSegue(withIdentifier: "LoginComplete", sender: self.navigationController)
}
}else{
print ("Bad TouchID")
}
})
}
}
Thanks

Answer 1

Try implementing this function and checking from where it's being called:
override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
}
Remember that as you're calling the segue from your code, if you have already added a segue action from your button to the next ViewController in the storyboard you should remove it and only create a connection between your LoginViewController to the one you want to call

Answer 2

As the documentation states, if you do not override the shouldPerformSegue method, the default implementation returns true for all segues.
The shouldPerformSegue(withIdentifier:sender:) method should determine whether a segue with the specified identifier will or will not be called depending on the return value of your implementation.
Since you already check whether the TouchID authorization was successful, you don't actually need to call shouldPerformSegue, but rather you need to call performSegue.
context.evaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, localizedReason: "For login you need to use your TouchID", reply: {(wasSuccessful, error) in
if wasSuccessful {
DispatchQueue.main.async {
self.performSegue(withIdentifier: "LoginComplete", sender: self.navigationController)
}
}else{
print ("Bad TouchID")
}
})