为什么在ui：composition中未呈现ui：fragement

Question

I'm a beginner with JSF and Java, please be nice!

I'm trying to render a specific block if a user is an Administrator.

I have a template. This template render correctly a specific block if the user is logged.

admin.xhtml:

    <ui:composition template="../../WEB-INF/tpl/admin/template.xhtml">
        <ui:define name="sectionTitle">Admin</ui:define>

        <!-- Logged as Admin -->
        <ui:fragment rendered="#{user.admin}">
            <ui:define name="body">
                <h3>Welcome</h3>
                <p>Please choose an administration task!</p>
            </ui:define>
        </ui:fragment>

    </ui:composition>

template.xhtml:

<div class="header">
    <h2>
        <ui:insert name="sectionTitle"> Default Section Title</ui:insert>
    </h2>
    <ui:insert name="logBox">
        <ui:fragment rendered="#{not user.logged}">
            <ui:include src="login.xhtml"></ui:include>
        </ui:fragment>

        <ui:fragment rendered="#{user.logged}">
            <h:form>
                <h:commandButton value="Logout"
                    action="#{userService.logout}" />
            </h:form>
        </ui:fragment>
    </ui:insert>
</div>

    <div class="corebody">
        <ui:insert name="body"> Default Section Content</ui:insert>
    </div>

I can move the rendered block inside the template like so:

<ui:fragment rendered="#{user.admin}">
        <ui:insert name="body"> Default Section Content</ui:insert>
</ui:fragment>

but this don't seem ok to me regarding the responsability of each files ( this don't seem really generic, why should such a thing be in the template? ).

Am I missing something really obvious?

Answer 1

Anything outside <ui:define> and <ui:composition> is ignored during building the view and don't end up in JSF component tree.

You need to put <ui:fragment> inside <ui:define> .

<ui:composition template="../../WEB-INF/tpl/admin/template.xhtml">
    <ui:define name="sectionTitle">Admin</ui:define>

    <!-- Logged as Admin -->
    <ui:define name="body">
        <ui:fragment rendered="#{user.admin}">
            <h3>Welcome</h3>
            <p>Please choose an administration task!</p>
        </ui:fragment>
    </ui:define>

</ui:composition>

An alternative is to use JSTL <c:if> as that runs during view build time already:

<ui:composition template="../../WEB-INF/tpl/admin/template.xhtml">
    <ui:define name="sectionTitle">Admin</ui:define>

    <!-- Logged as Admin -->
    <c:if test="#{user.admin}">
        <ui:define name="body">
            <h3>Welcome</h3>
            <p>Please choose an administration task!</p>
        </ui:define>
    </c:if>

</ui:composition>

See also:

• How to include another XHTML in XHTML using JSF 2.0 Facelets?
• JSTL in JSF2 Facelets... makes sense?

Answer 2

<ui:composition template="../../WEB-INF/tpl/admin/template.xhtml">
    <ui:define name="sectionTitle">

        <!-- Logged as Admin -->
        <ui:fragment rendered="#{user.admin}">
            <ui:define name="body">
                 <h3>Welcome</h3>
                 <p>Please choose an administration task!</p>
            </ui:define>
        </ui:fragment>
    </ui:define>
</ui:composition>

Try this.