code: private void setupComboBoxSite() {
  
          IndexedContainer container = CmsVaadinUtils.getAvailableSitesContainer(A_CmsUI.getCmsObject(), "title");
          m_site.setContainerDataSource(container);
          m_site.setItemCaptionMode(ItemCaptionMode.PROPERTY);
          m_site.setItemCaptionPropertyId("title");
          m_site.setNullSelectionAllowed(false);
          m_site.setTextInputAllowed(false);
          m_site.setValue(A_CmsUI.getCmsObject().getRequestContext().getSiteRoot());
          m_site.addValueChangeListener(new ValueChangeListener() {
  
              private static final long serialVersionUID = -1019243885633462477L;
  
              public void valueChange(ValueChangeEvent event) {
  
                  changeSite();
                  removeUnvalidPathFields();
              }
          });
  
          m_project.setContainerDataSource(CmsVaadinUtils.getProjectsContainer(A_CmsUI.getCmsObject(), "caption"));
          m_project.setItemCaptionPropertyId("caption");
          m_project.select(A_CmsUI.getCmsObject().getRequestContext().getCurrentProject().getUuid());
          m_project.setNewItemsAllowed(false);
          m_project.setNullSelectionAllowed(false);
          m_project.setTextInputAllowed(false);
      }
docs: Sets up the combo box for the site choice.<p>