Jakarta Struts Cookbook

3.5. Using Indexed Properties in a JSTL Loop

Problem

You want to use indexed bean properties with the Struts html tags in a JSTL c:forEach loop instead of Struts logic:iterate loop.

Solution

To create fields for a simple indexed property, use the bean:define tag to expose the loop counter as a scripting variable that can be used in a runtime expression:

<c:forEach var="theItem" items="${MyForm.myItems}" varStatus="loopStatus">
  <bean:define id="itemIndex">
    <c:out value="${loopStatus.index}"/>
  </bean:define>
  <br/><html:text property='<%="myItem["+itemIndex+"]"%>'/>
</c:forEach>

If the indexed property is a nested bean and you are using the indexed="true" property, then replace the Struts logic:iterate tag with the JSTL c:forEach:

<c:forEach var="theNestedItem" items="${MyForm.myNestedItems}">
  <br/><html:text name="theNestedItem" 
              property="nestedProperty"
              indexed="true"/>
</c:forEach>

Discussion

The c:forEach tag provided by JSTL provides additional functionality and can be easier to use than the logic:iterate tag. The items to loop through can be specified using EL. The JSTL tag permits greater control for looping over a subset of the collection, and details on the loop status are easily obtained. However, as is common to all JSTL tags, no scripting variables are created. As was shown in other recipes in this chapter, runtime expressions may have to be used when dealing with indexed properties. This is particularly true if you are not using the struts-el tag libraries.

The bean:define ...