UIWebView delegate method shouldStartLoadWithRequest: equivalent in WKWebView?

Question

I have a module inside my iOS 7+ app which is a UIWebView. The html page loads a javascript that creates custom-shaped buttons (using the Raphaeljs library). With UIWebView,

Answer 1

In Swift you can do something like this:

func webView(webView: WKWebView, decidePolicyForNavigationAction navigationAction: WKNavigationAction, decisionHandler: (WKNavigationActionPolicy) -> Void) {

    switch navigationAction.request.URLString {
    case "http://action.is.needed/some-action":
        self.someFunc()
        decisionHandler(.Cancel)
        break
    default:
        decisionHandler(.Allow)
        break
    }

}

And this is the link in web page:

Hello world!