Web view is blank after creating the bridge object

[visgotti]

import UIKit
import WebKit
class ViewController: UIViewController, WKNavigationDelegate {
    var mainWebView : WKWebView = WKWebView.init();
    override func viewDidLoad() {
          super.viewDidLoad()
          mainWebView.frame = view.frame;
          self.view.addSubview(mainWebView)
    }
    override func viewWillAppear(_ animated: Bool) {
         var bridge = WKWebViewJavascriptBridge.init(for: mainWebView);
         let url = URL(string: "http://127.0.0.1:8283")!
         mainWebView.load(URLRequest(url: url))
    }
}

When I comment out WKWebViewJavascriptBridge.init(for: mainWebView); the web page loads fine, otherwise it is a blank white screen. Any ideas why?

[visgotti]

Closing.. here's what worked.

import UIKit
import WebKit
class ViewController: UIViewController, WKNavigationDelegate {
    var mainWebView : WKWebView = WKWebView.init();
    var bridge : WKWebViewJavascriptBridge!;
    override func viewWillAppear(_ animated: Bool) {
        mainWebView.frame = self.view.frame;
        mainWebView.navigationDelegate = self;
        bridge = WKWebViewJavascriptBridge( for: mainWebView)!;
        bridge!.setWebViewDelegate(self);
        let url = URL(string: "http://127.0.0.1:8283")!
        mainWebView.load(URLRequest(url: url))
    }
    
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        bridge!.setWebViewDelegate(self);
        self.view.addSubview(mainWebView)
    }
}