Problems with dynamic values in EL expressions

[ibenjes]

Hi,

I've got a generic table where the user can select which columns are visible.
The JSF part looks like this (as part of a table):

<rich:columns id="#{column.id}" value="#{columns}" label="#{column.label}" var="column" index="ind" sortable="true" sortBy="#{data[column.value]}" sortOrder="#{column.sortOrder}" rendered="#{column.rendered}">
          <f:facet name="header">
               #{column.label}
          </f:facet>
          
          <s:fragment rendered="#{column.dataType eq 'java.lang.String'}">
                      #{data[column.value]}
                 </s:fragment>
          <s:fragment rendered="#{column.dataType eq 'java.lang.Boolean'}">
                      #{data[column.value] ? 'Yes' : 'No'}
                 </s:fragment>
          <s:fragment rendered="#{column.dataType eq 'java.util.Date'}">
                      <h:outputText value="#{data[column.value]}">
                           <s:convertDateTime pattern="#{userProfile.dateFormat}"/>
                      </h:outputText>
                 </s:fragment>
          
     </rich:columns>

The column is a Bean which defines the column label, sorting order and which member of the actual data object (in most cases an entity) is shown in that row/column via

#{data[column.value]}

On the java side you would define the column with something like

new Column(1,"Column Label","memberName");

with memberName being the member of the entity you want to show in that column.
So in the JSF page you would get

#{data[memberName]}

. That all works fine when you only want to access members in the entity. But e.g. you have a Object Company in the entity and that Company class has a member String companyName. You don't want to show Company in the data table but company.companyName

The problem is if you specify

new Column(1/*index*/,"Column Label","company.companyName");

You get

sortBy="#{data[column.value]}": Property 'company.companyName' not found on type XXX

I've tried:

company.companyName
company.getCompanyName
company[companyName]

all with no success. It seems you can't really nest EL expressions. Do you know a way to do it?

I then tried to write my own tag handler (see here:
http://seamframework.org/Documentation/CreatingCustomELFunctions

and do

#{e:evalEl(e:concat('data.',column.value))}

but that doesn't work either.

Any suggestions? My last resort is to have a method
getObj(Object data)
on Column which uses Reflection to find the right members but there must be a better way.