How to check if WkWebView finish loading in Objective-C?

Question

I want to load HTML pages using WkWebView and I want to show the page just after it's finished loading. As long as it's loading I would like to show an activity indicator on an empty View. I create two view a loadingView and a wkWebView. While the page is loading I add to VC as subview the loadingView and after I want to remove loadingView and add wkWebView. Here is my code:

    [self addSubview:_loadingView];
    _wkWebView = [[WKWebView alloc] initWithFrame:self.frame];
    _wkWebView.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, self.frame.size.height);

    //Send a request to wkUrlconnection
    NSURL *wkUrl = [NSURL URLWithString:self.wkUrlString];
    NSURLRequest *wkRequest = [NSURLRequest requestWithURL:wkUrl];

    //Here I want to check if it's loaded and then remove loadingView and add wkWebView
    [_wkWebView loadRequest:wkRequest];
    [self.loadingView removeFromSuperview];
    [self addSubview:_wkWebView];

Can someone show me how to check while it's loading and if finish refresh the VC? Thank you for your answers.

Answer 1

I think the WKNavigationDelegate's webView:didFinishNavigation: delegate callback is what you're looking for.

Configure and present your activity indicator when you start to load and then stop and remove it from view when the callback is called.

Answer 2

For anyone who is experiencing the issue of a webpage containing multiple frames and therefore doing multiple loads which interrups your load animation, I have implemented the following and it works for me in all the situations I have come across so far:

Swift:

var loadCount: Int = 0

override func viewDidLoad() {
    super.viewDidLoad()

    startLoading()
    webview.navigationDelegate = self
    let request = URLRequest(url: url)
    webview.load(request)
}

func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
    loadCount += 1
}

func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {

    loadCount -= 1

    DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) { [weak self] in
        if self?.loadCount == 0 {
            self?.stopLoading()
        }
    }

}

The basic idea is to start your load animation before you request the url, then count each request being made and only stop the load animation when your request count == 0. This is done after a slight delay as I find that some frames queue up requests synchronously so the next load will begin before the 0.1 second delay has completed.

( ͡° ͜ʖ ͡°)

Answer 3

for swift 4.2:

func webView(_ webView: WKWebView,
                 didFinish navigation: WKNavigation!){
        print("loaded")
}

be sure to set delegate for webView in didLoad (or similar)

webView.navigationDelegate = self

Answer 4

class WebViewVC: UIViewController {
    
    // MARK: IBOutlets
    @IBOutlet weak var webView: WKWebView!
    @IBOutlet weak var activityIndicator: UIActivityIndicatorView!
    
    // MARK: Life cycle
    override func viewDidLoad() {
        super.viewDidLoad()
        
        webView.navigationDelegate = self
        loadWebsite()
    }
}

// MARK: WKWebView
extension WebViewVC: WKNavigationDelegate {
    func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
        activityIndicator.startAnimating()
    }
    
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        activityIndicator.stopAnimating()
    }
}

// MARK: Private methods
extension WebViewVC {
    private func loadWebsite() {
        guard let url = URL(string: "google.com") else { return }
        
        let urlRequest = URLRequest(url: url)
        webView.load(urlRequest)
    }
}