iOS: UIWebViewDelegate methods/functions with CustomWebView

Question

UIWebViewDelegate methods/functions are not being called from custom web view`.

Code I've tried:

class CustomWebView: UIWebView, UIWebViewDelegate {


    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.delegate = self
    }

    // Web view delegate method - not called upon web view load
    func webViewDidFinishLoad(_ webView: UIWebView) {
        print("webViewDidFinishLoad")
    }

   /*
   // tried this also
   override func didMoveToSuperview() {
    super.didMoveToSuperview()
    self.delegate = self
   }
   */
}

// View controller code

class WebControllerVC: UIViewController, UIWebViewDelegate {
   @IBOutlet weak var wvWebView: CustomWebView!

    override func viewDidLoad() {
        super.viewDidLoad()
        wvWebView.delegate = self
        wvWebView.loadHTMLString(htmlString, baseURL: nil) // htmlString is string variable with data in HTML format 
    }

}

I tried to look around following SO Posts, but can't see solution for custom web view.

• UIWebViewDelegate methods not getting called
• ShouldStartLoad of custom UIWebViewDelegate not being called when UIWebView request starts loading
• UiWebView delegate methods not getting called
• uiwebviewdelegate not called from non-visible uiwebview