UIBinder with Widget - gwt

Question

I am trying to add a widget to a panel using UIBinder but the composite simply doesn't load, here is my xml:
<ui:UiBinder xmlns:ui='urn:ui:com.google.gwt.uibinder'
xmlns:g='urn:import:com.google.gwt.user.client.ui'
xmlns:my='urn:import:com.abc.client.test.ui'>
<g:HTMLPanel ui:field="mainLayoutPanel">
<g:SimplePanel ui:field="menuPanel" >
<my:MainMenuViewImpl ui:field="mainMenu"/>
</g:SimplePanel>
<!-- the widget causing the issue -->
<my:FinancialsNav ui:field="nav"/>
<g:SimplePanel ui:field="mainPanel" />
</g:HTMLPanel>
</ui:UiBinder>
The corresponding java class:
public class AppLayoutImpl extends Composite implements AppLayout{
#UiField
HTMLPanel mainLayoutPanel;
interface AppLayoutUiBinder extends UiBinder<Widget,AppLayoutImpl>{}
private static AppLayoutUiBinder binder=GWT.create(AppLayoutUiBinder.class);
#UiField
SimplePanel menuPanel;// nav at the top
#UiField(provided=true)
FinancialsNav nav;// nav on the side
#UiField
SimplePanel mainPanel;// center
#UiField(provided=true)
MainMenuViewImpl mainMenu;
public AppLayoutImpl(ClientFactory clientFactory){
mainMenu=clientFactory.getMainMenuView();
nav=clientFactory.getNav();
initWidget(binder.createAndBindUi(this));
}
#Override
public Widget asWidget(){
return this;
}
}
And the Widget causing the issue:
public class FinancialsNav extends Composite implements ClickHandler{
private VerticalPanel nav=new VerticalPanel();
// Operations
private DisclosurePanel operationsWrapper=new DisclosurePanel(Proto2.constants.financials_navigation_operations());
private NavButton product=new NavButton(Proto2.constants.financials_navigation_products(),
SharedUtilities.PRODUCT_TOKEN);
private NavButton generalOptions=new NavButton(Proto2.constants.financials_navigation_generalOptions(),"");
private ArrayList<NavButton[]> buttons;
private NavButton[] operationsButtons={product,vc,fc,emp,others};
//...
private NavButton[] optionsButtons={generalOptions};
private final EventBus bus;
public FinancialsNav(EventBus bus){
this.bus=bus;
buildNav();
initWidget(nav);
}
private void buildNav(){
buttons=new ArrayList<NavButton[]>();
buttons.add(operationsButtons);
//...
buttons.add(optionsButtons);
int n=buttons.size();
int nn;
for(int i=0;i<n;i++){
nn=buttons.get(i).length;
for(int j=0;j<nn;j++){
(buttons.get(i)[j]).addClickHandler(this);
(buttons.get(i)[j]).setStylePrimaryName(NAV_BUTTON_STYLE);
if(i==0){
operationsWrapper.add(buttons.get(i)[j]);
//...
}else if(i==4){
optionsWrapper.add(buttons.get(i)[j]);
}
}
}
nav.add(operationsWrapper);
// ...
nav.add(optionsWrapper);
}
The FinancialsNav widget works fine when not used with UIBinder and the rest of AppLayout works as expected when the FinancialsNav isn't there.
I spent hours on this looking at various tutorials and examples but simply could not find what is wrong with the code. I also tried various workaround such as declaring a panel in the UIBinder instead of the FinancialsNav and the adding the nav to the panel.
Also everything is in the same package so it shouldn't be an import issue.
Any help would be much appreciated...
Here is the clientFactory
public class ClientFactoryImpl implements ClientFactory{
private static final EventBus eventBus=new SimpleEventBus();
private static final PlaceController placeController=new PlaceController(eventBus);
private static final CreatePlanServiceAsync createPlanService=GWT.create(CreatePlanService.class);
private static final FinancialsNav navView=new FinancialsNav(eventBus);
private static final MainMenuViewImpl mainMenuView=new MainMenuViewImpl();
#Override
public EventBus getEventBus(){
return eventBus;
}
#Override
public PlaceController getPlaceController(){
return placeController;
}
#Override
public FinancialsNav getNav(){
return navView;
}
#Override
public MainMenuViewImpl getMainMenuView(){
return mainMenuView;
}
#Override
public CreatePlanServiceAsync getCreatePlanService(){
return createPlanService;
}
}

Answer 1

FinancialsNav widgets has constructor with arguments. So create no argument constructor.
The entry <my:FinancialsNav ui:field="nav"/> is equals to new FinancialsNav().
In most cases this means that they must be default instantiable; that is, they must provide a zero-argument constructor. you have to pass argument
/** Used by MyUiBinder to instantiate FinancialsNav */
#UiFactory FinancialsNav makeFinancialsNav() { // method name is insignificant. do start with make
return new FinancialsNav(eventBus);
}
Refer Using a widget that requires constructor args
Can you show clientFactory code!!

Answer 2

Ok I found the error, actually not directly related to UIBinder.
Simultaneously to implementing UIBinder I was trying to reduce the number of tables used by the panels in my app.
As I noticed that the disclosure panel is based on a table I removed an intermediary vertical panel I had in the FinancialsNav.
Hence having DisclosurePanel --> Buttons instead of DisclosurePanel --> VerticalPanel --> Buttons. And that is causing the entire block not to show.
#adenoyelle and #bumika: thank you for help