Custom tags help

[sebastian pettersson]

I am trying to create a custom tag that generates the code for an HTML table in this manner:

<my:drawTable maxColoumns='3' items="${aCollectionOfBeans}" var="currentBean">
     ${currentBean.aProperty}
</my:drawTable>

Here the tag draws a table of no more than 3 coloumns and as many rows as it takes to include all items. And in each cell of the table the value of currentBean.aProperty is printed.

The tag is defined through a tag file:

<%@ tag body-content="scriptless" %>
<%@ attribute name="maxColoumns" required="true" %>
<%@ attribute name="items" rtexprvalue="true" required="true" %>
<%@ attribute name="var" rtexprvalue="false" required="true" %>
<%@ variable name-from-attribute="var" alias="current" variable-class="java.lang.Object" scope="NESTED" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
 
<table width="0" border="0" cellspacing="0" cellpadding="0">
<c:forEach items="${items}" var="current">
<c:set var="counter" value="${counter + 1}" /> 
<c:if test="${counter%maxColoumns == 1}"><tr></c:if>
<td class="formtext">
<jsp:doBody var="cellContent" />
${cellContent}
</td>
<c:if test="${counter%maxColoumns == 0}"></tr></c:if>
</c:forEach>
</tr>
</table>

So the table generating code works, i've come that far. What doesn't work is the line: "${currentBean.aProperty}" in the jsp code. This Exception is thrown:

javax.servlet.ServletException: javax.servlet.jsp.JspException: Unable to find a value for "aProperty" in object of class "java.lang.String" using operator "."

So apparently the container sees currentBean as a String object instead of a bean. If I change the EL expression to "${currentBean}" no exception is thrown and it evaluates to the fully specified classname of currentBean.

Can anyone help to get it working like i want it too with code like the first code snippet?

Thanks in advance,

Sebastian
[ April 10, 2005: Message edited by: sebastian pettersson ]

[seb petterson]

Ok, so now i realize that the value of the variable "items", as it is declared in the jsp, is receieved as a String in the tag. And the forEach loop is probably just iterating over a set of substring elements separated by some token in the Collection's toString() value. Hence the call throwing the exception looks something like this:

"com.mycompany.beans.myBean@27cd63".getAProperty()

So the question is how to define a custom tag (through a tag file preferably) that takes a bean (or any non-String value) variable.

Any feedback is appreciated, even if you don't know the answer.

Thanks.

[sebastian pettersson]

Matter resolved:

<%@ attribute name="items" rtexprvalue="true" required="true" type="java.util.Collection" %>