Duplicate email Alert Swift + Parse - swift

Question

I'm trying to have it so when a user creates an account... if their email hasn't been used before an Alert box appears saying "Account created" and if the email is already in created (on Parse) then an alert should appear notifying the user.
I can't seem to get my code to do both..only display one message. What am I doing wrong here?
Thanks!
func createNewUser() {
let newUser = PFUser()
newUser.email = emailSignUp.text
newUser.username = emailSignUp.text
newUser.password = passwordSignUp.text
newUser.signUpInBackgroundWithBlock { ( success: Bool, error: NSError?) -> Void in
if newUser.username != nil {
let alert: UIAlertController = UIAlertController(title: "Account created", message: "Please confirm your email", preferredStyle: .Alert)
let okButton = UIAlertAction(title: "OK", style: .Default) { action -> Void in
}
alert.addAction(okButton)
self.presentViewController(alert, animated: true, completion: nil)
}
else {
let alert: UIAlertController = UIAlertController(title: "Email already registered", message: "Please enter a different email", preferredStyle: .Alert)
let okButton = UIAlertAction(title: "OK", style: .Default, handler: nil)
alert.addAction(okButton)
self.presentViewController(alert, animated: true, completion: nil)
}
}
}

Answer 1

If memory serves the error that's returned if a user already exists is a different string than a generic error. You can try to match the error string and then display an alert if it matches or a different one if it's just an error (like the error string itself).
newUser.signUpInBackgroundWithBlock { ( success: Bool, error: NSError?) -> Void in
if error != nil {
if let errorString = error.userInfo?[“error”] as? String {
if errorString == “username \(emailSignUp.text) already taken” {
// Create alert that address is taken
} else {
// Create other case alert, though it may make sense to just display the error string in an alert box
}
}
} else {
// Do your usual stuff
}