Minimal example dialog:
I've just googled up this solution. Basically the idea is to use actionListener instead of button's action, and in backing bean you add callback parameter which will be then check in button's oncomplete method. Sample partial code:
JSF first:
Backing bean:
public void doAction(ActionEvent actionEvent) {
// do your stuff here...
if (ok) {
RequestContext.getCurrentInstance().addCallbackParam("saved", true);
} else {
RequestContext.getCurrentInstance().addCallbackParam("saved", false);
}
}
Hope this helps someone :)