Submit in a fetch mode collapsed rows - jsf

Question

I have this datatable:
<p:dataTable id="necesidades"
value="#{registrarAccionDosBean.accionDos.necesidadesConTema}"
rendered="#{not empty registrarAccionDosBean.accionDos.necesidadesConTema}"
var="necesidad"
rowKey="#{necesidad.idNecesidad}">
<p:column style="width:16px">
<p:rowToggler />
</p:column>
<p:rowExpansion>
<h:panelGroup id="grupoTema">
<h:panelGroup id="edicion" rendered="#{necesidad.tema.idTema ne null}">
<p:row>
<p:column >
<h:outputLabel value="#{etiq.lbl_comunes_requerido} #{etiq.etiqueta_checkbox_transparenciasFocalizadas}" styleClass="textoAcciones"/>
</p:column>
<p:column >
<!-- Nested data table -->
<p:dataTable id="transparenciasInplace"
var="transparencias"
value="#{registrarAccionDosBean.transparenciasFocalizadas}"
selection="#{necesidad.tema.transparenciasFocalizadas}"
rowKey="#{transparencias.idTf}">
<f:facet name="header">
Objetives
</f:facet>
<p:column selectionMode="multiple" style="width:16px;text-align:center"/>
<p:column>
<h:outputLabel value="#{transparencias.descripcion}" styleClass="textoAccionesSmall"/>
</p:column>
</p:dataTable>
</p:column>
</p:row>
</h:panelGroup>
</h:panelGroup>
</p:rowExpansion>
</p:dataTable>
I have n rows collapsed with information inside of each of them, this information was persisted in different times and days, so I need to save some information plus the n rows as a whole, the problem is that the rows are collapsed when is show on screen and I want to be in that way because a can have a lot rows on screen and if I show them expanded it will be hard to read, but when I send it through a command button the table inside my collapsed row are setting null, I need to expand each of them in order to properly send all the information.
So I want to send the information collapsed but in some way force to fetch the information inside of each of them
I am getting the information from the database right, because there I just fetch my query and get the information right, so my problem is on my jsf page I think