Swift - validating UITextField - swift

Question

I have these outlets in my app:
#IBOutlet var name1: UITextField!
#IBOutlet var name2: UITextField!
#IBOutlet var name3: UITextField!
#IBOutlet var name4: UITextField!
#IBOutlet var newButton: UIButton!
What I tried to do is the following:
Every time the user types something in one of these four UITextFields or deletes something, I want to check if any UITextField is empty
If any UITextField is empty, the button should be disabled.
If all UITextFields are set (not empty), the button should be enabled.
My code:
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
setButton()
return true
}
func setButton() {
let inputValid = checkInput()
if inputValid {
newButton.enabled = true
} else {
newButton.enabled = false
}
}
func checkInput() -> Bool {
let name1Value = name1.text
let name2Value = name2.text
let name3Value = name3.text
let name4Value = name4.text
if !name1Value.isEmpty && !name2Value.isEmpty && !name3Value.isEmpty && !name4Value.isEmpty {
return true
}
return false
}
Ok, it works 50% for now.
When I type one character in each UITextField, the button is still disabled.
When I add a second one to any UITextField, the button gets enabled etc...
Can anyone help me with this?

Answer 1

Alternatively, you can use this, which is called every time a key is pressed:
name1.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
name2.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
name3.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
name4.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
func textFieldDidChange(textField: UITextField) {
if name1.text?.isEmpty || name2.text?.isEmpty || name3.text?.isEmpty || name4.text?.isEmpty {
//Disable button
} else {
//Enable button
}
}

Answer 2

Swift 4
- Here is how I have solved it trying to avoid long conditionals
- This will also allow you to do realtime validation on each individual textfield, unlike the accepted answer, you can update your UI according to what the user is typing.
let textfields : [UITextField] = [name1, name2, name3, name4]
for textfield in textfields {
textfield.addTarget(self, action: #selector(textFieldDidChange(_:)), for: .editingChanged)
}
#objc func textFieldDidChange(_ textField: UITextField) {
//set Button to false whenever they begin editing
yourButton.isEnabled = false
guard let first = textFields[0].text, first != "" else {
print("textField 1 is empty")
return
}
guard let second = textFields[1].text, second != "" else {
print("textField 2 is empty")
return
}
guard let third = textFields[2].text, third != "" else {
print("textField 3 is empty")
return
}
guard let forth = textFields[3].text, forth != "" else {
print("textField 4 is empty")
return
}
// set button to true whenever all textfield criteria is met.
yourButton.isEnabled = true
}

Answer 3

The textField:shouldChangeCharactersInRange: method gets called BEFORE the contents of the text field have changed.
You should special-case the current text field and figure out if it's new contents are going to be blank after the edit.
Something like this:
textField.text.length > range.length - replacementString.length
(That's off the top of my head, and not debugged. Plus you would have to come up with logic that makes sure all the other fields are non-blank, and use the logic above to test the contents of the current field.)

Answer 4

Take a look at UITextFieldValidator. I have created a validator which covers almost each validation required in an app. Also its in swift. So go ahead and check it out.

Answer 5

Try this code. Hope you will get what to do.
func updateSaveButtonState() {
let text = titleTextField.text ?? ""
saveButton.isEnabled = !text.isEmpty
}
#IBAction func textEditingChanged(_ sender: UITextField) {
updateSaveButtonState()
}
#IBAction func returnPressed(_ sender: UITextField) {
titleTextField.resignFirstResponder()
}

Answer 6

Swift 4 & 5
Firstly, you create a function like setupTextFields() and you call it in viewDidLoad() (something like this):
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
setupTextFields() //You call the function here.
}
func setupTextFields() {
name1.addTarget(self, action: #selector(self.textFieldDidChange(_:)), for: UIControl.Event.editingChanged)
name2.addTarget(self, action: #selector(self.textFieldDidChange(_:)), for: UIControl.Event.editingChanged)
name3.addTarget(self, action: #selector(self.textFieldDidChange(_:)), for: UIControl.Event.editingChanged)
name4.addTarget(self, action: #selector(self.textFieldDidChange(_:)), for: UIControl.Event.editingChanged)
}
Then you create another function which each time you press a key, that function will be called. I'll show you two options, then you choose which fits better for you. Usually, Option 1 would be considered a better implementation for Swift.
Option 1
#objc func textFieldDidChange(_ textField: UITextField) {
guard !name1.text!.isEmpty else {
button.isEnabled = false
return
}
guard !name2.text!.isEmpty else {
button.isEnabled = false
return
}
guard !name3.text!.isEmpty else {
button.isEnabled = false
return
}
guard !name4.text!.isEmpty else {
button.isEnabled = false
return
}
button.isEnabled = true
}
Option 2
#objc func textFieldDidChange(_ textField: UITextField) {
if name1.text!.isEmpty || name2.text!.isEmpty || name3.text!.isEmpty || name4.text!.isEmpty {
button.isEnabled = false
} else {
button.isEnabled = true
}
}