richface组件的延迟加载

我正在尝试“懒加载”一个richface组件。不知怎么的,没有页面刷新,我无法渲染它。我希望避免整页刷新。

情况:

基本页面加载了:

菜单Bean.java

private MenuBarComponent getLazyMenuBarComponent() {
    if (lazyMenuBar != null) {
        return lazyMenuBar;
    }
    lazyMenuBar = new MainMenuBarLazy(); // no children
    return lazyMenuBar;
}

按下“激活菜单”按钮后:

第.xhtml页

<a4j:region id="main-menu-region">
    <h:form  id="mainMenu-form">
        <rich:dropDownMenu  binding="#{menuBarBean.menuBar}" 
                        id="HOOFDMENU" 
                        showEvent="mouseup" 
                        onclick="showMenu();" 
                        styleClass="menu-hdr-btn"
                        hideDelay="3600000"
                        showDelay="0"
                        onshow="onMenuShow();" 
        />
        <a4j:jsFunction name="fetchMenu" action="#{menuBarBean.fetchMenu}"
            render="@region @form HOOFDMENU">       <!-- I THOUGHT THIS SHOULD WORK -->
        </a4j:jsFunction>
    </h:form> 
</a4j:region>

<a4j:jsFunction name="fetchMenu" action="#{menuBarBean.fetchMenu}">
</a4j:jsFunction>

<javascript>
  function displayMenu(){
      #{rich:component('HOOFDMENU')}.show();
  }
</javascript>

菜单Bean.java

public String fetchMenu() {
        if(currentMenuBar.getChildrenSize() > 1){
            return "";
        }
        showMenuBar = true;
        currentMenuBar = getMenuBarComponent();   // The component gets pointed to the full menu
        return "TRUE";// "RELOAD" triggers a full page refresh and shows the full menu;
    }

public UIComponent getMenuBar() {
    if (currentMenuBar == null) {
        currentMenuBar = getLazyMenuBarComponent();
    }
    menuBarComponent = currentMenuBar.build();  // Here the component gets builded. It is chosen to build it in the getter because in the build there is also a check of the users ROLE, which can be changed on the fly.
    return menuBarComponent;
}

编辑后添加

javascript.js

function showMenu(){ // gets triggered when pressed on the dropdown component
    fetchMenu();     // triggers the build-full-menu action
    displayMenu();   // sets dropdownbox to show (the menu should show now), I only get the borders of an empty list
}

如果在按下菜单激活按钮后按F5,将显示完整菜单。 如果我回来 fetchMenu() return=“RELOAD”页面重新加载,同时显示完整菜单。 如果我尝试重新阅读区域/表单或HOOFDMENU,我不会得到任何重新阅读的完整菜单。

我如何才能只重新加载页面的菜单部分而不重新加载整个页面?