How to detect when user used Password AutoFill on a UITextField

Question

I\'ve implemented all the app and server changes necessary to support Password Autofill on iOS 11, and it works well. I\'d like it to work a little better.

My usern

Answer 1

Found a solution.

When the password manager is used to autofill username + password, it will trigger didBeginEditing twice, faster than a human ever could.

So, I calculate the time between the events. If the time is extremely fast, then I assume that autofill (e.g. FaceID or TouchID) was used to enter credentials and auto-trigger whatever UI is next -- in my case, the User tapping "Sign-in".

Obviously, you have to set up the correct delegation of the UITextFields you want to monitor, but once you do that:

var biometricAutofillTime: Date!

func textFieldDidBeginEditing(_ textField: UITextField) {
    if biometricAutofillTime != nil {
        if Date().timeIntervalSince(biometricAutofillTime) < 0.1 {
            // NOTE: Need to hesitate for a very short amount of time,
            //        because, otherwise, the second UITextField (password)
            //        won't yet be populated
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) { self.didTapSignin() }
        }
        biometricAutofillTime = nil
    }
    biometricAutofillTime = Date()
}