WKWebview popup for PDF close button?

Question

My app is running WKWebview to display a website. When an element is clicked it calls window.open() which is caught and depending on the link a PDF is shown:

func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration, for navigationAction: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {
    popupWebView = WKWebView(frame: view.bounds, configuration: configuration)
    popupWebView!.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    popupWebView!.navigationDelegate = self
    popupWebView!.uiDelegate = self
    popupWebView!.allowsBackForwardNavigationGestures = true
    
    view.addSubview(popupWebView!)
    return popupWebView!
}

In my case it works perfectly fine.

My problem is now that I can not go back because the PDF was opened in fullscreen. Is it possible to enable navigation controls in this kind of pop-up webview? Or is there any way to control the back behaviour by a "back" swipe? I tried to do it via allowsBackForwardNavigationGestures but it does not seem to work...

Answer 1

I don't think the WKWebView has an easy way add a back button, you will need to add the back button on your view (or navigation controller). I've been able to do it like this:

Observe the canGoBack property change of the webView instance in order to enable/disable (or hide/show) the back button like this:

popupWebView.addObserver(self, forKeyPath: #keyPath(WKWebView.canGoBack), options: .new, context: nil)

And on the view controller:

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    if keyPath == "canGoBack" {
        if webView.canGoBack {
            // enable the back button
        } else {
            // disable the back button
        }
    }
}

Finally when the user taps the back button it is only necessary to call:

popupWebView.goBack()