FieldEvents.BlurEvent

Hi,

I refer to the page https://vaadin.com/book/-/page/application.events.html, discussing different ways to intercepts and handle events.

I'm curious about the following not working:

[...]

this.username = new TextField();

// alternative #1: it works
this.username.addListener((FieldEvents.BlurListener)this);

// alternative #2: does not work
this.username.addListener(FieldEvents.BlurEvent.class, this, "blur");

addComponent(this.username);

public void blur(FieldEvents.BlurEvent event) {
[...]
}

[...]

I get no errors, but the second way of adding a listener has no consequences (either the event is not fired or it is not intercepted).

Thanks, Marco

More explicitly, it seems to me that:

public void addListener(Class<?> eventType, Object target, String methodName) {}

does not work when eventType is FieldEvents.BlurEvent (while, for example, it works for Button.ClickEvent).

Thanks,
Marco

Marco Zanon: public void addListener(Class<?> eventType, Object target, String methodName) {}

This method (which the javadoc discourages from using) does not tell the client that it should send such events to the server - unless someone else has registered a listener with the appropriate API, no events are sent by the client. It works directly with events that are generated on the server side, though.

I would recommend using the addListener(listenerImplementation) method. If you absolutely need to register a listener using an arbitrary method, see the protected method AbstractComponent.addListener(eventIdentifier, eventType, target, method) that is used by addListener(FocusListener) etc.

Henri, thanks very much for your answer.

Marco