pull to refresh in webView using webkit in swift 4 - webview

Question

I'm already add pull to refresh function in my code, the icon refresh will appear when I start pull it but when I had make changing in the webview such as tick the checkbox or enter the text in textbox,,why It not reset back to the default view?
import UIKit
import WebKit
class ViewController: UIViewController,WKNavigationDelegate,UIWebViewDelegate {
#IBOutlet weak var activityIndicator: UIActivityIndicatorView!
#IBOutlet weak var webView: WKWebView!
#IBOutlet var containerView: UIView? = nil
override func viewDidLoad() {
super.viewDidLoad()
self.view.addSubview(self.activityIndicator)
self.view.addSubview(self.webView)
let url:URL = URL(string : "https://www.facebook.com/")!
let urlRequest : URLRequest = URLRequest(url: url)
webView.load(urlRequest)
//activity indicator
self.webView.addSubview(self.activityIndicator)
self.activityIndicator.startAnimating()
self.webView.navigationDelegate = self
self.activityIndicator.hidesWhenStopped = true
self.webView.navigationDelegate=self;
//refresh
webView.scrollView.bounces = true
let refreshControl = UIRefreshControl()
refreshControl.addTarget(self, action: #selector(ViewController.refreshWebView), for: UIControlEvents.valueChanged)
webView.scrollView.addSubview(refreshControl)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear( animated )
let url:URL = URL(string : "https://www.facebook.com/")!
let urlRequest : URLRequest = URLRequest(url: url)
webView.load(urlRequest)
}
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
activityIndicator.stopAnimating()
}
func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
activityIndicator.stopAnimating()
}
func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
activityIndicator.startAnimating()
}
#objc func refreshWebView(sender: UIRefreshControl) {
print("refersh")
//
sender.endRefreshing()
}
}

Answer 1

EDIT: I found a solution how the pull to refresh Indicator waits til the WebView did Finish loading:
I have used a UIRefreshControl instead an UIActivityIndicator.
import UIKit
import WebKit
class ViewController: UIViewController,WKNavigationDelegate,UIWebViewDelegate {
#IBOutlet weak var webView: UIWebView!
override func viewDidLoad() {
super.viewDidLoad()
let url:URL = URL(string : "https://www.google.com")!
let urlRequest : URLRequest = URLRequest(url: url)
webView.loadRequest(urlRequest)
//refresh
webView.scrollView.alwaysBounceVertical = true
let refreshControl = UIRefreshControl()
refreshControl.tintColor = .white
let attributes = [NSForegroundColorAttributeName: UIColor.white]
let attributedTitle = NSAttributedString(string: "refreshing ...", attributes: attributes)
refreshControl.attributedTitle = attributedTitle
refreshControl.addTarget(self, action: #selector(ViewController.refreshWebView), for: UIControlEvents.valueChanged)
refreshControl.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
webView.scrollView.refreshControl = refreshControl
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear( animated )
let url:URL = URL(string : "https://www.google.com")!
let urlRequest : URLRequest = URLRequest(url: url)
webView.loadRequest(urlRequest)
}
func webViewDidFinishLoad(_ webView: UIWebView) {
self.webView.scrollView.refreshControl?.endRefreshing()
}
func webView(_ webView: UIWebView, didFailLoadWithError error: Error) {
self.webView.scrollView.refreshControl?.endRefreshing()
}
func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {
return true
}
#objc func refreshWebView(sender: UIRefreshControl) {
print("refresh")
self.webView.reload()
}