Suggested Improvement

[QNENet]

The code in MainLayout at present is

    protected void onAttach(AttachEvent attachEvent) {
        RouteRegistry registry = attachEvent.getUI().getInternals().getRouter()
                .getRegistry();

        UI ui = attachEvent.getUI();
        fillSideBar(attachEvent.getUI());
        routesListener = registry
                .addRoutesChangeListener(event -> ui.access(() -> {
                    fillSideBar(ui);
                    if (!isCurrentRouteExists(ui)) {
                        ui.navigate(DeregisteredRouteView.class,
                                ui.getInternals().getActiveViewLocation()
                                        .getPath());
                    }
                }));

    }

This results in a rather untidy view if the remnant of a previous view remain in the address bar.

The suggestion is to provide a direct navigate to the MainView for all remnants.

I have tried the following but it did not work for me.

    protected void onAttach(AttachEvent attachEvent) {
        RouteRegistry registry = attachEvent.getUI().getInternals().getRouter()
                .getRegistry();

        UI ui = attachEvent.getUI();
        fillSideBar(attachEvent.getUI());
        routesListener = registry
                .addRoutesChangeListener(event -> ui.access(() -> {
                    fillSideBar(ui);
                    if (!isCurrentRouteExists(ui)) {
                        ui.navigate(MainView.class);
                    }
                }));

    }

[QNENet]

As the result of using 20.0.0.rc1 to fix system fail on stop of a bundle the ugliness of the process is more predominate now when menu items are removed. The current process would confuse users.

Please advise if this issue should be raised elsewhere, but it may be specific to Karaf version only.

[mstahv]

Yup, this is just related to this demo. May modifying the Route annotation in DeregisteredView to @Route(value = "unknown", layout = MainLayout.class) would be enough? Then the message would be shown in the "main layout".