MainViewController+Extension.swift

class MainViewController: UIViewController {
    
    @IBOutlet var mainView: MainView!

    override func viewDidLoad() {
        super.viewDidLoad()
        mainView.delegate = self
    }
}

extension MainViewController: MainViewDelegate {
    
    func searchButtonTappedWithTerm(with searchTerm: String) {
        print("The text in UITextField is: \(searchTerm)")
    }
}