Textfield didChange with timer - swift

Question

I'm working on autocompletion in my project and I would like to detect when the textfieldDidChange value and call a method (link to API) 500MS after that.
I hope it's clear enough
Thank for your help !

Answer 1

In Swift 3, you probably want to connect to "editing changed" not "value changed", and reset the timer and start another timer:
weak var timer: Timer?
#IBAction func didChangeEditing(_ sender: UITextField) {
timer?.invalidate()
timer = .scheduledTimer(withTimeInterval: 0.5, repeats: false) { [weak self] timer in
// trigger your autocomplete
}
}
Or you can alternatively hook into shouldChangeCharactersIn. For example:
class ViewController: UIViewController, UITextFieldDelegate {
#IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
textField.delegate = self // or you can do this in IB
}
weak var timer: Timer?
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
timer?.invalidate() // cancel prior timer, if any
timer = .scheduledTimer(withTimeInterval: 0.5, repeats: false) { [weak self] timer in
// trigger your autocomplete
}
return true
}
}

Answer 2

First make sure to make your class the TextField's delegate:
class yourClass: UIViewController, UITextFieldDelegate{
//...
}
And then in viewDidLoad():
textField.delegate = self
numbersTextField.addTarget(self, action: #selector(self.textFieldDidChange), for: .editingChanged)
After that, you can use a timer, like this:
var timer = Timer()
var count = 0
func textFieldDidChange(textField: UITextField){
timer.invalidate()
timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(self.timerFunc), userInfo: nil, repeats: true)
}
func timerFunc(){
count += 1
if count == 5{
timer.invalidate()
// do your things here down here, I assumed that your method is called autocomplete
autocomplete()
}
}
Hope it helps!