Best way for creating an dynamic crosstable

[luc4]

Hi,

i try to implement an 'dynamic crosstable'. The user have the ability to add both items for rows and items for columns.

My first approach was to use the <rich:columns> tag, but like in the documentation pointed out the values must be available at component tree build time. So i think it's not possible to add row/column objects via an action/actionListener because the values will then not available when the tree is build?


Second approach is to use <c:forEach> that works:

<c:forEach items="#{bean.rowMapKeys}" var="objectKey" varStatus="rowIndex">
 <c:if test="#{rowIndex.index == 0}>
 <tr>
 <th>CrossHead</th>
 <c:forEach items="#{bean.result[objectKey]}" var="property" varStatus="rowIndex">
 <th><h:outputText id="columnHead_#{rowIndex.index}_#{columnIndex}" value="#{property.label}"/></th>
 </c:forEach>
 </tr>
 </c:if>

 <tr>
 <rich:column>
 <h:outputText value="#{objectKey.name}"/>
 </rich:column>

 <rich:columns id="compareColumns_#{rowIndex.index}_#{columnIndex}" value="#{bean.result[objectKey]}" var="property" index="columnIndex">
 <h:outputText id="propertyValue_#{rowIndex.index}_#{columnIndex}" value="#{property.value}"/>
 </rich:columns>
 </tr>
</c:forEach>

But then i have to write my custom html for headers etc. and can't use skinning 'out of the box'.

Two additional questions to this approach:
1. I use <rich:column/s> tags without wrapping it in an <rich:dataTable> element (like shown in the docs) ... This is legal? The rendered html shows an table element around the tabledata elements ...

2. I think this solution works because <c:forEach> will be evaluated at build time? But how can it works? The values for the columns will be fetched in the INVOKE_APPLICATION Phase from the db (not available at build time)... I really don't understand that?


Third approach is to programmatic build the table and use the binding attribute like described here http://balusc.blogspot.com/2006/06/using-datatables.html#PopulateDynamicDatatable.

What will be the best/natural way to achieve this requirement with richfaces? Maybe some people implemented something similar and have some suggestions?

Greetings Luca