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iOS

Posted by Ektoras Drandakis
Ektoras Drandakis
29,580 Points

Xcode: unexpectedly found nil while unwrapping option value in label

When a new user registers in want to assign the username text in a label in another viewcontroller but i get a fatal error crash. Here is my code:

 @IBAction func signupBtn(sender: UIButton) {

        var email = self.emailField.text
        var password = self.passwordField.text
        var username = self.usernameField.text

        self.actInd.startAnimating()

        var newUser = PFUser()
        newUser.email = email
        newUser.password = password
        newUser.username = username
        userVC.usernameLbl.text = username // Here i get the crash!

        newUser.signUpInBackgroundWithBlock({ (succeed, error) -> Void in

            self.actInd.stopAnimating()

            if((error) != nil) {

                var alert = UIAlertView(title: "Error", message: "\(error)", delegate: self, cancelButtonTitle: "Ok")
                alert.show()
            } else {

//                var alert = UIAlertView(title: "Success", message: "Signed Up", delegate: self, cancelButtonTitle: "Ok")
//                alert.show()
                self.change_screen()

            }
        })
    }

1 Answer

Alvin Abia
Alvin Abia
Courses Plus Student 23,034 Points

I suspect that your crash is related to the fact that your username variable is contained only within the signupBtn func. By trying to set the text value of a label of another view controller to this variable, it will cause an error as the value of username that it's trying to access is out of that other view controller's scope. Here's two ways you could resolve this:

1) Move your username variable to outside the function so it's a member variable of the actual class whose function this is (so it would be a property of your initial view controller) and can be accessed outside of the sign up function. Then you could use username's value in prepareForSegue when setting the usernameLbl text value in userVC.

2) Log in the new user on successful signup so that after a user successfully signs up and logs in with Parse, you can access their username globally using PFUser's currentUser class method. Then in your userVC you can set your label like this:

usernameLbl.text = PFUser.currentUser().username

Hope this resolves your issue!

Ektoras Drandakis
Ektoras Drandakis
29,580 Points

Yes this worked!

Thank you!