Swift - Delegate method with TabBar

Question

I have a very simple project where one View (Sending view) should change appearance of second View (Receiving view). I am trying to use delegation but I have a problem with assign variable "delegate" in SendingVC. I tried to do it in override func "prepare" in ReceivingVC, but this method is not called.

I think this code could work, but I don't know where I should put it:

let sendVC : SendingVC! = tabBarController?.viewControllers![1] as! SendingVC
sendVC.delegate = self

ReceivingVC:

import UIKit

class ReceivingVC: UIViewController, DataSendDelegate {

@IBOutlet weak var Label: UILabel!

func userDidEnterData(data: String) {
    Label.text = data
}

override func viewDidLoad() {
    super.viewDidLoad()
}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    let sendVC : SendingVC! = tabBarController?.viewControllers![1] as! SendingVC
    sendVC.delegate = self
}
}

SendingVC:

import UIKit

protocol DataSendDelegate {
func userDidEnterData(data: String)
}

class SendingVC: UIViewController {
var delegate: DataSendDelegate? = nil

override func viewDidLoad() {
    super.viewDidLoad()
}

@IBAction func setTextButton(_ sender: UIButton) {
    if delegate != nil {
        delegate?.userDidEnterData(data: "some text")
    }
}
}

Storyboard img

Answer 1

Thanks bjd23, it works perfectly. So solution is put it to the viewDidLoad method

Edit: If you have this code:

if delegate != nil {
    delegate?.userDidEnterData(data: "some text")
}

in the viewDidLoad instead of button action, I recommend to put it to the viewDidAppear or viewWillAppear, because if your Sending view is loaded first, nothing will happen