webkit2gtk-4.0 script_message_received does not work vala

Question

I am creating a WebKit WebView from Vala.

I connected the UserContentManager and registered a script message handler.

I also connected the script_message_received signal before that, as it is writte in the Valadoc documentation.

The script was successfully registered, but script_message_received does not fire. After executing the script

window.webkit.messageHandlers.test.postMessage ('test');

Nothing happens.

WebView webKit = new WebView ();

webKit = new WebView.with_user_content_manager (new WebKit.UserContentManager ());

webKit.user_content_manager.script_message_received.connect ((js_result) =>
{
    debug ("Test result");
});

if (! webKit.user_content_manager.register_script_message_handler ("test"))
    debug ("Failed to register script message handler");

What do I have to do so that the signal is fired?

Answer 1

The problem was in public class Main: Object

You need to use public class Main: Gtk.Window

Otherwise nothing works.