WKWebview - Complex communication between Javascript & native code

Question

In WKWebView we can call ObjectiveC/swift code using webkit message handlers eg: webkit.messageHandlers..pushMessage(message)

It works we

Answer 1

I have a workaround for question1.

PostMessage with JavaScript

window.webkit.messageHandlers..postMessage(function(data){alert(data);}+"");

Handle It in your Objective-C project

-(void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
    NSString *callBackString = message.body;
    callBackString = [@"(" stringByAppendingString:callBackString];
    callBackString = [callBackString stringByAppendingFormat:@")('%@');", @"Some RetString"];
    [message.webView evaluateJavaScript:callBackString completionHandler:^(id _Nullable obj, NSError * _Nullable error) {
        if (error) {
            NSLog(@"name = %@ error = %@",@"", error.localizedDescription);
        }
    }];
}