Dynamic jsf menu

In this blog I will explain how you can create a dynamic menu in jsf pages from a bean. The data of the menu can for example come from a xml or from a database table. In my other blog I use adf taskflow with a xml menu, this time I use menu items.

First we create a taskflow with two views and with two control flow cases

Now we can create a jsf template with the menubar where we add our menu items.
<br /> <af:panelSplitter orientation="vertical" inlineStyle="width:846px;"<br /> splitterPosition="56"><br /> <f:facet name="first"><br /> <af:group><br /> <af:facetRef facetName="menu"/><br /> <af:menuBar id="menuBar" binding="#{Menu.initMenu}"/><br /> </af:group><br /> </f:facet><br /> <f:facet name="second"><br /> <af:facetRef facetName="body"/><br /> </f:facet><br /> </af:panelSplitter><br />
We create the menu bean and defined it as a request managed bean in the adfc-config.xml

    private RichMenuBar initMenu;

    public void createMenus(PhaseEvent phaseEvent) {

            boolean addMenu = true;
            for (Iterator iterator = initMenu.getChildren().iterator(); iterator.hasNext();) {
                UIComponent component = (UIComponent) iterator.next();
                if ( component.getId().equalsIgnoreCase("menuMain")){
                    addMenu = false;
                }
            }           
           if (addMenu) {
            //Create Menu and set id and text
                RichMenu menuMain = new RichMenu();
                menuMain.setId("menuMain");
                menuMain.setText("Main");

                RichCommandMenuItem menuPage1 = new RichCommandMenuItem();
                menuPage1.setId("page1");
                menuPage1.setText("Page 1");
                menuPage1.setActionExpression(getMethodExpression("page1"));
    
                RichCommandMenuItem menuPage2 = new RichCommandMenuItem();
                menuPage2.setId("page2");
                menuPage2.setText("Page 2");
                menuPage2.setActionExpression(getMethodExpression("page2"));

                menuMain.getChildren().add(menuPage1);
                menuMain.getChildren().add(menuPage2);
                initMenu.getChildren().add(menuMain);
            }
    }
    private MethodExpression getMethodExpression(String name) {
        Class [] argtypes = new Class[1];
        argtypes[0] = ActionEvent.class;
        FacesContext facesCtx = FacesContext.getCurrentInstance();
        Application app = facesCtx.getApplication();
        ExpressionFactory elFactory = app.getExpressionFactory();
        ELContext elContext = facesCtx.getELContext();
        return elFactory.createMethodExpression(elContext,name,null,argtypes);
    }


    private ValueExpression getValueExpression(String name) {
        FacesContext facesCtx = FacesContext.getCurrentInstance();
        Application app = facesCtx.getApplication();
        ExpressionFactory elFactory = app.getExpressionFactory();
        ELContext elContext = facesCtx.getELContext();
        return  elFactory.createValueExpression(elContext, name, Object.class);
    }

We are ready to create the two pages and we only have to add beforePhase attribute to f:view element.
<br /><?xml version='1.0' encoding='windows-1252'?><br /><jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.0"<br /> xmlns:h="http://java.sun.com/jsf/html"<br /> xmlns:f="http://java.sun.com/jsf/core"<br /> xmlns:af="http://xmlns.oracle.com/adf/faces/rich"><br /> <jsp:directive.page contentType="text/html;charset=windows-1252"/><br /> <f:view beforePhase="#{Menu.createMenus}"><br /> <af:document><br /> <af:form><br /> <af:pageTemplate viewId="/main.jspx"><br /> <f:facet name="menu"/><br /> <f:facet name="body"><br /> <af:outputText value="page1"/><br /> </f:facet><br /> </af:pageTemplate><br /> </af:form><br /> </af:document><br /> </f:view><br /></jsp:root><br />And we are finished. Here is the 11g example project