API Review: Service Worker Post Message Setting

[chetanpandey1266]

No description provided.

[oldnewthing]

Is there a race window where the service worker could try to post a message before we register the handler?

If we are worried about events coming from the old page, maybe the place to register these event handlers is in NavigationStarted?

[oldnewthing]

Should probably use reinterpret_cast<HWND>(m_appWindow.Id().Value) as the parent window for the message box.

[oldnewthing]

Suggested change

	m_appWindow->AsyncMessageBox(message.str(), L"Message from Service Worker");
	m_appWindow->AsyncMessageBox(message.str(), L"Message from Service Worker (relayed by Main Thread)");

[oldnewthing]

The bottom half of the C++ sample is missing from the C# sample. I'm guessing it's something like

   webView.CoreWebView2.WebMessageReceived += (s, e) => {
      var message = e.TryGetWebMessageAsString();
      if (message == "MessageFromMainThread") {
         m_appWindow.AsyncMessageBox($"""
            Message:
            {message}
            Service Worker Message from Main thread
            """, "Message from Service Worker");
      }
   };

   WebView.CoreWebView2.Profile.ServiceWorkerManager.ServiceWorkerRegistered += (s, e) => {
      var serviceWorkerRegistration = e.ServiceWorkerRegistration;
      var serviceWorker = serviceWorkerRegistration.ActiveServiceWorker;
      if (serviceWorker != null) {
         SetupEventsOnServiceWorker(serviceWorker);
      } else {
         serviceWorkerRegistration.ServiceWorkerActivated += (s2, e2) => {
            SetupEventsOnServiceWorker(e2.ActiveServiceWorker);
         };
      }
   };
}

private void SetupEventsOnServiceWorker(CoreWebView2ServiceWorker serviceWorker)
{
   serviceWorker.WebMessageReceived += (s, e) => {
      var message = e.TryGetWebMessageAsString();
      m_appWindow.AsyncMessageBox($"""
         Message:
         {message}
         """, "Message from Service Worker");
   };
}

[oldnewthing]

Unused variable.

[oldnewthing]

Presumably should avoid double-registering if the setting is toggled multiple times.

[oldnewthing]

Plural verb? Plural "Workers"?

Suggested change

	Boolean IsWebViewScriptApisForServiceWorkerEnabled { get; set; };
	Boolean AreWebViewScriptApisForServiceWorkersEnabled { get; set; };

Maybe tweak for better reading:

            Boolean AreWebViewScriptApisEnabledForServiceWorkers { get; set; };

[FrankC-msft]

Precedent is to increment a number suffix of the interface, for new properties on CoreWebView2Settings, rather than insert adjectives. (see ICoreWebView2Settings12 adding IsNonClientRegionSupportEnabled. If we haven't otherwise already changed patterns, stay consistent for new properties.

[FrankC-msft]

This was meant to be ICoreWebView2StagingSettings to align with interface_name in c# below, correct? (and would change to ICoreWebView2SettingsN if we change to that pattern.)