Question

In my application I am using JSF 1.2. I dont want to use facelets taglib so I have included a JSP using jsp:include attribute. I want to pass a variable to subpage which will decide the style class value. Below is the code for parent.jsp

<f:view>
...
    <f:subview id="navigation">
        <jsp:include page="/subpage/child.jsp">
            <jsp:param value="page9" name="pageName"/>
        </jsp:include>
    </f:subview> 
...
</f:view>

Child jsp is

            <f:subview id="navigation">
    ...
                <t:commandLink id="page9" value="mylink" action="#{manageBean.someAction}" 
                  styleClass="#{param.pageName == 'page9'?'stepLinkActive':'stepLink'}" />
    ...
            </f:subview>

In above code stepActiveLink class is not getting applied to myLink. Infact #{param.pageName} value is blank.

I found this link on SO which works if I use surrounding the command link like below

        <c:if test='${param.pagename eq "page9"}'>      
            <t:commandLink id="page9"
                value="#{msgs['DICT.ISSUE_CONTROL.SPECIAL_INFO']} "
                action="#{bondIssueBean.gotoModifyPage9}" styleClass="stepLinkActive" />
        </c:if>
        <c:if test='${param.pagename ne "page9"}'>      
            <t:commandLink id="page9"
                value="#{msgs['DICT.ISSUE_CONTROL.SPECIAL_INFO']} "
                action="#{bondIssueBean.gotoModifyPage9}" styleClass="stepLink" />
        </c:if>

I have lot of commandLinks which will need to duplicate commandlink definition just to change style class. I wonder, going forward if any other param is passed then it may increase duplicate codes. My questions are

1. Why JSF EL can not identify param value – ${param.paramName}? I also tried accessing param variable using #{param[‘pageName’]} but no luck.
2. How I can replace above if..else so that I can have single commandlink definition?

Answer 1

It fails “by design”. For a technical background story see also JSF issue 629, which summarizes as follows:

After some discussion on this issue, we’re going to mark this issue as WONTFIX
for the follow reasons:

• mainly, this wouldn’t have worked in 1.1 if it had not been for the side
  effect of a fix to get the RI to work in an older version of Tomcat. As
  soon as that fix was removed, jsp:param would no longer work.
• the fix for 1.2 is very risky and there probably would have been unintended
  side effects as a result of adding it.

There’s however a possible workaround with help of <c:set> which copies it into the request scope so that it’s available in JSF EL #{} as well.

<c:set var="param_pageName" value="${param.pageName}" scope="request" />
<t:commandLink id="page9" value="mylink" action="#{manageBean.someAction}" 
    styleClass="#{param_pageName == 'page9' ? 'stepLinkActive' : 'stepLink'}" />