UIWebView delegate method shouldStartLoadWithRequest: equivalent in WKWebView?

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, I set delegate to self. The delegate method webView: shouldStartLoadWithRequest: navigationType: is called each time one of my custom button is pressed. The requests should not be handled by the html, but rather by the iOS code. So I used a request convention (read somewhere here on stackoverflow) using "inapp" as the scheme of my requests. I then check for the host and take the appropriate action.

This code works fine on iOS 7. But the web views appear blank on iOS 8 (bug?), so I decided to use WKWebView for iOS 8 devices. The web views now render fine (and amazingly faster!), but my buttons have no effect.

I tried using - (WKNaviation *)loadRequest:(NSURLRequest *)request, but it's not called.

I can't find a direct equivalent of the UIWebView delegate method webView: shouldStartLoadWithRequest: navigationType:. What's the best way of handling those requests with WKWebView?

I've been looking for a good explanation myself, but haven't found one. I've used the following in my app and everything seems to work (Edit: updated based on ccoroom's comment):

UIWebViewDelegate     - webView:shouldStartLoadWithRequest:navigationType:
WKNavigationDelegate  - webView:decidePolicyForNavigationAction:decisionHandler:

Here's the other UIWebViewDelegate methods:

UIWebViewDelegate     - webViewDidStartLoad:
WKNavigationDelegate  - webView:didCommitNavigation:

UIWebViewDelegate     - webViewDidFinishLoad:
WKNavigationDelegate  - webView:didFinishNavigation:

UIWebViewDelegate     - webView:didFailLoadWithError:
WKNavigationDelegate  - webView:didFailNavigation:withError:
                      - webView:didFailProvisionalNavigation:withError:

I'd love for someone to confirm this for me though.

Edit: Actually, I've answered the question you had in the title (although I'm no longer confident that webView:didCommitNavigation: is called at the exact same point in the lifecycle), but re-reading your description it looks like what you actually need to know about is how to reimplement a Javascript/Objective-C bridge using WKWebView. So have a look at my other answer.

To answer the original question, the equivalent of webView:shouldStartLoadWithRequest:navigationType: in UIWebView is webView:decidePolicyForNavigationAction:decisionHandler: in WKWebView. These methods are called before each request is made (including the initial request) and provide the ability to allow/disallow it.

Just use the following method , it's a part of WKNavigationDelegate

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {

    NSURLRequest *request = navigationAction.request;
    NSString *url = [[request URL]absoluteString];

    decisionHandler(WKNavigationActionPolicyAllow);
}