Do something after WKWebView has finished loading and scraping specific page - swift

Question

what I'm trying to do is perform an action only after the WKWebView I'm using has finished loading and scraping the page.
Here's the code for the webView:
let webView = WKWebView()
let url = URL(string: "https://web.spaggiari.eu/home/app/default/menu_webinfoschool_genitori.php?custcode=")!
let request = URLRequest(url: url)
webView.load(request)
What I want to do is show the button to "Connect" only after the process has fished (that specific process and not when the webView finishes loading every time). For now I'm using DispatchQueue to wait for seconds hoping the page loads in time.
DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(4)) {
UIView.animate(withDuration: 0.8, animations: {
self.registerButton.alpha = 1
self.registerButton.isEnabled = true
})
UIView.animate(withDuration: 0.8, delay: 0.4, animations: {
self.blurButton.alpha = 1
})
}
I'm using Xcode with Swift3

Answer 1

this code indicates that page fully loaded, may this help you
func webpageFullyLoaded(_ str: String) {
if (str == "complete") || (str == "interactive") {
print("page completely loaded")
}
}
func webViewDidFinishLoad(_ webView: UIWebView) {
webpageFullyLoaded(webView.stringByEvaluatingJavaScript(from: "document.readyState"))
}

Answer 2

WKWebView has this delegate
/*! #abstract The web view's navigation delegate. */
weak open var navigationDelegate: WKNavigationDelegate?
WKNavigationDelegate :
A class conforming to the WKNavigationDelegate protocol can provide
methods for tracking progress for main frame navigations and for deciding
policy for main frame and subframe navigations
This delegate has a method, that might help you
/*! #abstract Invoked when a main frame navigation completes.
#param webView The web view invoking the delegate method.
#param navigation The navigation.
*/
#available(iOS 8.0, *)
optional public func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!)
So you can try this
func loadPage() {
let webView = WKWebView()
webView.navigationDelegate = self
let url = URL(string: "https://web.spaggiari.eu/home/app/default/menu_webinfoschool_genitori.php?custcode=")!
let request = URLRequest(url: url)
webView.load(request)
}
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
// Do your work here
}
Also make sure your self here conforms to WKNavigationDelegate.
Update
To handle loading of different web pages in the same WKWebView you can,
func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: #escaping (WKNavigationActionPolicy) -> Swift.Void) {
print("Page Being loaded is \(navigationAction.request), you can do your work here")
decisionHandler(.allow)
}
You can read more about what you can do in the navigation delegate here