SaveState and resetState only called once for a component in a dataTable?!

Question

I am fairly new to JSF and am trying to write some custom components using MyFaces 1.0.9.
I am trying to write choose, when and otherwise components to mirror the functionality that XSL provides. I also created function and argument tags that allow me to call any method on a binding bean via a method binding. The when tag allows a function tag as a child so that instead of a test to a value binding, I can call a function on a bean to get the test value.
Example:<x:choose>
<x:when>
  <x:function name="#{myBean.myFunction}">
   <x:argument value="testValue" />
   <%-- I will render some components here --%>
  </:x:function>
<x:otherwise><%-- here is the else components to render --%></x:otherwise>
</x:choose>I am evaluating the UIWhen components in the encodeChildren method of my UIChoose component.
Everything is working fine until I started using my tags/components in a data table. Now, I have not tried the normal dataTable, I am using the MyFaces extended one, but I haven't done anything that should make a difference.
What is happening is that my UIWhen tag's saveState and restoreState methods are only being called once, despite the fact that there are 3 rows in my data table. So what happens, is that the isRendered() property of my UIWhen component is not restored per row, but only once. So my controls are either all validated or none are validated based on the rendered state of the last row only, not each individual row as expected.
I may be able to "fake" this into working by saving hidden input tags when rendering my UIWhen components and then restoring the rendered property when the page is posted, but that seems like a hack to me. Isn't the purpose of the saveState and restoreState supposed to handle this?
Is this a bug in the dataTable component/tag or is this a shortcomming of JSF?
Either way, is there a better way then trying to save my rendered state per row as hidden elements?
I looked at the code of the normal dataTable renderer in the MyFaces source, and it does not seem to call restore or save state that I could see.
Thanks for the help,
Andrew

Answer 1

Hello!
You can place in the data model editor formula and placeholder
columns outside of any groups. I think you need for each of your
summary-attibutes a placeholder column and one formula column.
Use the formula column to populate the placeholders via PL/SQL.
Afterwords you can reference the placeholders anywhere you want.
Regards,
Hajo Winkler