Change custom text field background color and text color IOS Swift

Question

I'm using following custom text field class to change appearance of the text field. Now I need to change text field's background color, text color and place holder color, when user start editing and end editing the text field. How to do it, using this class.

import Foundation
import UIKit

class CustomTextField: UITextField{

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        //Border
        self.layer.cornerRadius = 15.0;
        self.layer.borderWidth = 1.5
        self.layer.borderColor = UIColor.whiteColor().CGColor

        //Background
        self.backgroundColor = UIColor(white: 1, alpha: 0.0)

        //Text
        self.textColor = UIColor.whiteColor()
        self.textAlignment = NSTextAlignment.Center
    }

}

Answer 1

In your CustomTextField class you can add a property observer:

var change: Bool = false {
    didSet {
        textColor = change ? .yellow : .black
        backgroundColor = change ? .blue : .white
    }
}

and in your ViewController:

func textFieldDidBeginEditing(textField: UITextField) {
    customTextField.change = true
}

func textFieldDidEndEditing(textField: UITextField) {
    customTextField.change = false
}

Don't forget to set the delegate of your textfield, in storyboard or programmatically.

EDIT:
Shortened the code and updated for Swift 3