With GWT, is there a way to not load widgets declared in uibinder xml files?

Question

One common design I have with GWT is to create a widget which contains two children: A and B.

I declare these two widgets A and B in the uibinder file associated to my main widget.

What I want to do is to load or not widget A depending on an if statement.

Ideal approach is to set provided=true for widget A and to set widget A to null when I want to not load this widget. But GWT throws an error.

Is there a way to declare widgets in uibinder and then not loading them ?

thanks

EDIT: after a lot of discussions, an ideal approach is to declared a field "provided=true" and "optional=true" when optional=true, createAndBindUI must not throw an Exception if the field is null. This is a clean approach.

If you think that this feature must exists in GWT, please star this issue: http://code.google.com/p/google-web-toolkit/issues/detail?id=5699

EDIT 2 : using the LazyPanel as described by Thomas seems to be a better way to handle this.

Answer 1

I stumbled on the GWT issue, which led me here, so here's my take on it, 20 months later.

Use a LazyPanel and set it to visible="false" so that it's content is not built until you need it (simply call setVisible(true) to reveal it, triggerring the lazy-initialization of its content.

LazyPanel is fully integrated with UiBinder so that you declare its content in the same UiBinder template, as if it were a SimplePanel, without even bothering creating a subclass of LazyPanel. See https://developers.google.com/web-toolkit/doc/2.4/DevGuideUiBinder#Lazy