tutorial-cdi-events.asciidoc

title	order	layout
Observable Vaadin Events	4	page

Observable Vaadin Events

The Vaadin CDI add-on publishes many Vaadin events to CDI.

It is not necessary to register a listener, using only an observer is sufficient to handle these events.

Events published to CDI include:

• ServiceInitEvent See VaadinServiceInitListener for more.

• PollEvent.

• BeforeEnterEvent. See Navigation Lifecycle for more.

• BeforeLeaveEvent. See Navigation Lifecycle for more.

• AfterNavigationEvent. See Navigation Lifecycle for more.

• UIInitEvent. See UIInitListener for more.

• SessionInitEvent. See Handling Session Initialization and Destruction for more.

• SessionDestroyEvent. See Handling Session Initialization and Destruction for more.

• ServiceDestroyEvent.

Warning

Whether or not ServiceDestroyEvent works with CDI during application shutdown depends on each specific implementation.

Example: Using the @Observes annotation to listen ServiceInitEvent.

public class BootstrapCustomizer {

    private void onServiceInit(@Observes
            ServiceInitEvent serviceInitEvent) {
        serviceInitEvent.addIndexHtmlRequestListener(
                this::modifyBootstrapPage);
    }

    private void modifyBootstrapPage(
            IndexHtmlResponse response) {
        response.getDocument().body().append(
                "<p>By CDI add-on</p>");
    }
}