Create nested tag files, which pass information from outer to inner

[Anoop Krishnan]

I want to create nested tag files, which pass information from outer to inner.

I tried the following

Parent tag called repeater.tag as given below

<%@tag body-content="scriptless" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c"%>
<%@variable name-given="setHeader" scope="NESTED" variable-class="java.lang.Boolean"%>
<c:set var="setHeader" value="true"></c:set>
<jsp:doBody></jsp:doBody>

Child tag is header.tag as given below

    
<%@tag body-content="scriptless" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c"%>
<c:if test="${setHeader}">
<jsp:doBody></jsp:doBody>
</c:if>

Now my test.jsp has the following content

    
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@taglib prefix="n" tagdir="/WEB-INF/tags"%>
<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c"%>
<n:repeater dataSource="<%=ds%>">
<n:header>Header = <c:out value="${setHeader}" /></n:header>
</n:repeater>

I was expecting the the out put as Header = true
but it doesn't happen because header.tag doesn't know anything about the EL variable

  setHeader  

.

I am confused .
I am setting setHeader as a EL varaible and it has a NESTED scope in the repeater.tag

   <%@variable name-given="setHeader" scope="NESTED" variable-class="java.lang.Boolean"%>
<c:set var="setHeader" value="true"></c:set> 

header.tag is nested inside the repeater so theoretically the EL variable must be accessible for it isn't it ?

But I am wrong why ? & Where ?
Do you have an idea ?

[Christophe Verré]

I can't tell much about it, but I suspect that the variable is made available in the tag and its caller page. The header tag uses its own page context, that would be why you can't access the variable. I don't remember if there's a way to synchronize variables for inner tag files...
If you can't find out how to do it, you could use an attribute for the header tag. The spec also recommends that for IN parameters, you should use attributes.