JavaServer Faces

Conditionally Disable Components Using Bean Properties

A better approach to conditionally include and disable components is to externalize all details for these decisions to a Java class. Example 6-6 shows this approach.

Example 6-6. Menu area using value expressions for conditional rendering (expense/stage1/menuArea.jsp)

<%@ page contentType="text/html" %>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>

<f:view>
  <h:form>
    <table cellpadding="0" cellspacing="0" width="100%">
      <tr>
        <td>
          <h:commandButton value="New" 
            disabled="#{reportHandler.newDisabled}" />
          <h:commandButton value="Delete" 
            disabled="#{reportHandler.deleteDisabled}" />
          <h:commandButton value="Submit" 
            disabled="#{reportHandler.submitDisabled}" />
          <h:commandButton value="Accept" 
            rendered="#{reportHandler.acceptRendered}"
                  disabled="#{reportHandler.acceptDisabled}" />
          <h:commandButton value="Reject" 
            rendered="#{reportHandler.rejectRendered}"
                              disabled="#{reportHandler.rejectDisabled}" />
        </td>
        <td align="right">
          You're logged in as "${pageContext.request.remoteUser}"
          [<h:outputLink value="../../logout.jsp" />
             <h:outputText value="Logout" />
           </h:outputLink>]
          [<h:outputLink value="prefUser.faces" />
             <h:outputText value="Preferences" />
           </h:outputLink>]
        </td>
      </tr>
    </table>
  </h:form>
</f:view>

All HTML form elements have an attribute named disabled. When set to true, the browser disables the corresponding user interface widget: a button can’t be clicked, ...