Can I handle alert inside UIWebViewDelegate?

Question

I can see the alert message inside my UIWebView

Answer 1

This seems to do it:

- (void)webViewDidFinishLoad:(UIWebView *)webView
{
    JSContext *ctx = [webView valueForKeyPath:@"documentView.webView.mainFrame.javaScriptContext"];
    ctx[@"window"][@"alert"] = ^(JSValue *message) {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"JavaScript Alert" message:[message toString] delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [alert show];
    };
}

Note: only tested on iOS 8.