Disable / Enable a button in Xcode - ios

Question

Hi i'm new with Swift programming.
What im trying to do is Disable my button (signIn) in viewDidLoad and only enable when the textfields have text in them. Here's what i've achieved so far. (not much though!)
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
signIn.isEnabled = false
// Do any additional setup after loading the view, typically from a nib.
}
#IBOutlet weak var emailtxt: UITextField!
#IBOutlet weak var passwordtxt: UITextField!
#IBOutlet weak var signIn: UIButton!
I need help to create a function in signIn that keeps button disabled until text fields (emailtxt & passwordtxt) have text in them and then proceed.
Glad if anyone can sort me.
Thanks in advance!

Answer 1

First add these for all of your textFields in viewDidLoad():
emailtxt.addTarget(self, action: #selector(textFieldDidChange(_:)),
for: UIControlEvents.editingChanged)
passwordtxt.addTarget(self, action: #selector(textFieldDidChange(_:)),
for: UIControlEvents.editingChanged)
Then use this:
#objc func textFieldDidChange(_ textField: UITextField) {
self.buttonIsEnabled()
}
func buttonIsEnabled() {
var buttonIsEnabled = true
defer {
self.signIn.isEnabled = buttonIsEnabled
}
guard let emailtxt = self.emailtxt.text, !emailtxt.isEmpty else {
addButtonIsEnabled = false
return
}
guard let passwordtxt = self. passwordtxt.text, ! passwordtxt.isEmpty else {
addButtonIsEnabled = false
return
}
}
I use this way in my codes and it works well.
Even you can add more methods for additional checking to buttonIsEnabled, like:
self.checkEmailIsValid(for: emailtxt)
Of course you should handle this method before:
func checkEmailIsValid(for: String) {
//...
}

Answer 2

Set ViewController as delegate for emailtxt and passwordtxt like this,
override func viewDidLoad() {
super.viewDidLoad()
signIn.isEnabled = false
emailtxt.delegate = self
passwordtxt.delegate = self
// Do any additional setup after loading the view, typically from a nib.
}
Conform your ViewController to UITextFieldDelegate and enable/disable as the text input is finished,
extension ViewController: UITextFieldDelegate {
func textFieldDidEndEditing(_ textField: UITextField) {
if emailtxt.text?.isEmpty == false && passwordtxt.text?.isEmpty == false {
signIn.isEnabled = true
} else {
signIn.isEnabled = false
}
}
}
Here is the fix for your code you shared.
import UIKit
extension UIViewController {
func hideKeyboardWhenTappedAround() {
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(UIViewController.dismissKeyboard))
tap.cancelsTouchesInView = false
view.addGestureRecognizer(tap)
}
#objc func dismissKeyboard() {
view.endEditing(true)
}
}
extension SignInVC: UITextFieldDelegate {
func textFieldDidEndEditing(_ textField: UITextField) {
if emailtxt.text?.isEmpty == false && passwordtxt.text?.isEmpty == false {
signIn.isEnabled = true
} else {
signIn.isEnabled = false
}
}
}
class SignInVC: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
signIn.isEnabled = false
emailtxt.delegate = self
passwordtxt.delegate = self
self.hideKeyboardWhenTappedAround()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBOutlet weak var emailtxt: UITextField!
#IBOutlet weak var passwordtxt: UITextField!
#IBOutlet weak var signIn: UIButton!
}

Answer 3

What I would do is create an IBAction from one of your text fields, and set the event to Editing Changed:
The code should look like this:
#IBAction func textFieldEditingDidChange(_ sender: UITextField) {
}
You can then connect that same outlet to both of your text fields by dragging from the outlet to your remaining field. If you've connected both correctly, clicking on the circle to the left of your IBAction should show two text fields:
The action will now be fired every time text changes in either of your fields.
Then, at the top of the file, I'd create a computed property that returns false unless there is something in both fields:
var shouldEnableButton: Bool {
guard let text1 = textField1.text, let text2 = textField2.text else {
return false
}
return text1.isEmpty && text2.isEmpty ? false : true
}
Finally, we add shouldEnableButton to our IBAction:
#IBAction func textFieldEditingDidChange(_ sender: UITextField) {
button.isEnabled = shouldEnableButton
}
Important
When you connect your second text field to the outlet, it will incorrectly assign Editing Did End as its event:
Delete this event and click and drag from Editing Changed to your IBAction:

Answer 4

Use SwiftValidator
https://github.com/SwiftValidatorCommunity/SwiftValidator
by this, you will set validation of email & password like below
import SwiftValidator
let validator = Validator()
validator.registerField(emailTextField, errorLabel: emailErrorLabel, rules: [RequiredRule(), EmailRule(message: "Invalid email")])
// MARK: - ValidationDelegate
extension ViewController: ValidationDelegate {
func validationSuccessful() {
self.loginUser()
}
func validationFailed(_ errors:[(Validatable ,ValidationError)]) {
for (field, error) in errors {
//Handle as per need - show extra label - shake view etc
/*
if let field = field as? UITextField {
Utilities.shakeTheView(shakeView: field)
}
error.errorLabel?.text = error.errorMessage
error.errorLabel?.isHidden = false
*/
}
}
}