ios webview refresh on scroll down

override func viewDidLoad() {
	// after webView.load
	let refreshControl = UIRefreshControl()
	refreshControl.addTarget(self, action: #selector(reloadWebView(_:)), for: .valueChanged)
	webView.scrollView.addSubview(refreshControl)
}
@objc func reloadWebView(_ sender: UIRefreshControl){
	webView.reload()
	sender.endRefreshing()
}