Disable button from going to next viewcontroller if textfields aren't filled - ios

Question

I'm having the issue with the textfields being empty and once I hit the button it continues to the next viewcontroller. I want to disable the button until all textfields are complete.
#IBAction func buttontapped(_ sender: Any, forEvent event: UIEvent) {
let loginFunc = Login()
loginFunc.login(First_Nm: First_Nm.text!, Pw: Pw.text!, Last_Name: Last_Name.text!, Email: Email.text!) { jsonString in
let response = jsonString
print(response)
if response.range(of: "failure") == nil {
DispatchQueue.main.async {
self.performSegue(withIdentifier: "goToHomeVC", sender: nil)
}
}
}

Answer 1

Add a check for the UITextFields to see if the text's isEmpty property is true before you proceed to performSegue.
#IBAction func buttontapped(_ sender: Any, forEvent event: UIEvent) {
if First_Nm.text!.isEmpty || Last_Name.text!.isEmpty || Email.text!.isEmpty {
print("Incomplete, show an alert for user's attention!")
return
}
//...
}
Add-on: Also, follow a standard naming convention for your properties. Eg: Instead of First_Nm use firstNameTextField.

Answer 2

If you want to achieve the disable and enable on the button based on textField input you can implement UITextFieldDelegate - textFieldDidChange
The code would look like this:
#IBOutlet weak var loginButton: UIButton!
#IBOutlet weak var firstNameTextField: UITextField!
#IBOutlet weak var lastNameTextField: UITextField!
#IBOutlet weak var passwordTextField: UITextField!
#IBOutlet weak var emailTextField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
firstNameTextField.delegate = self
lastNameTextField.delegate = self
passwordTextField.delegate = self
emailTextField.delegate = self
}
And on the bottom of the ViewController file you can create extension for UITextFieldDelegate
extension YourViewController: UITextFieldDelegate {
func textFieldDidChangeSelection(_ textField: UITextField) {
checkButtonState()
}
func checkButtonState() {
var validFirstName = false
var validLastName = false
var validPassword = false
var validEmail = false
if firstNameTextField.text != "" {
validFirstName = true
}
if lastNameTextField.text != "" {
validLastName = true
}
if passwordTextField.text != "" {
validPassword = true
}
if emailTextField.text != "" {
validEmail = true
}
if validFirstName && validLastName && validPassword && validEmail {
loginButton.isEnabled = true
} else {
loginButton.isEnabled = false
}
}
}
Then I would also recommend another check when the button is tapped similar to above answer however I think it could be a more extensive check on email and password. (Login might not be as important but during sign up you might want to validate password and email further than not empty)
You can make up your own rules but usually its something along the lines of
Validate password:
• Required 6-8 characters
if string.count < 6 {
print("Password must be more than 6 characters")
}
• Maybe require one capital letter or one number
Validate email:
• Should contain "#"
if !string.contains("#") {
print("probably not a valid email")
}
You can check the strings in the textfield to see if they meet the criteria if not return a login or sign up error to the user. Hopefully this gets you going in the right direction