Primefaces exporting only one expandable table - jsf

Question

I am trying to export a view to xlsx using PrimeFaces extensions. I have a main table and an expandable row with 2 tables inside.
The exporter works fine for the first dataTable in the expandable row, but not for the other one. Any ideas?
<p:dataTable id="mainTable" var="mainObject" value="#{mainBean.mainList}">
<p:column exportable="false" width="5%">
<p:rowToggler />
</p:column>
<p:column>
<f:facet name="header">
<h:outputText value="main column A"/>
</f:facet>
<h:outputText value="#{mainObject.columnA}" />
</p:column>
<p:column>
<f:facet name="header">
<h:outputText value="main column B"/>
</f:facet>
<h:outputText value="#{mainObject.columnB}" />
</p:column>
<p:rowExpansion>
<p:datTable id="relatedTableA" var="relatedA" value="#{mainObject.relatedA}">
<f:facet name="header">
<h:outputText value="Related A"/>
</f:facet>
<p:column>
<f:facet name="header">
<h:outputText value="Related A column A"/>
</f:facet>
<h:outputText value="#{relatedA.columnA}" />
</p:column>
<p:column>
<f:facet name="header">
<h:outputText value="Related A column B"/>
</f:facet>
<h:outputText value="#{relatedA.columnB}" />
</p:column>
</p:dataTable>
<p:datTable id="relatedTableB" var="relatedB" value="#{mainObject.relatedB}">
<f:facet name="header">
<h:outputText value="Related B"/>
</f:facet>
<p:column>
<f:facet name="header">
<h:outputText value="Related B column A"/>
</f:facet>
<h:outputText value="#{relatedB.columnA}" />
</p:column>
<p:column>
<f:facet name="header">
<h:outputText value="Related B column B"/>
</f:facet>
<h:outputText value="#{relatedB.columnB}" />
</p:column>
</p:dataTable>
</p:rowExpansion>
</p:dataTable>
<h:commandLink>
<p:graphicImage url="/resources/images/Excel32.png" width="32"/>
<pe:exporter type="xlsx" target="mainTable" fileName="fileExport" facetBackground="#AAFFBB" datasetPadding="4" />
</h:commandLink>
I followed this guide: https://www.primefaces.org/showcase-ext/sections/exporter/expandableTable.jsf
In my app, the view works perfect. I use the toggle and then it shows the 2 tables. The only problem is that it exports only one of the expandables.
Thanks for your time.

Answer 1

Seemes this is simply not supported.
In the exporter component source code when it comes to exporting the row expensions they have hard coded to consider the first child for each rowExpansion only:
if (rowExpansion.getChildren().get(0) instanceof DataTable) {
final DataTable childTable = (DataTable) rowExpansion.getChildren().get(0);
// ...
}
This is why you only get the first sub table in your output.
Using the customExporter feature you have the chance to extend the ExcelExporter and override the method exportCells which seemes responsible for your problem. Then change the behavior to do a loop on rowExpansion.getChildren() instead of just getting the first element.
General steps to configure a custom exporter from the linked site:
Step 1: Create a folder named META-INF under resouces folder.Below
META-INF folder create another folder called services.
Step 2: Creae a
file with the name "ExporterFactory" as a service(Fully binary name of
the service).
Here it should be org.primefaces.extensions.component.exporter.ExporterFactory.
Step 3:
Provide your own implementaions/providers of Exporter factory anywhere
in your project.
And copy the absolute path of custom exporter factory implementation in the ExporterFactory file
How to do : Copy the file content of DefaultExporterFactory and rename the file as CustomExporterFactory.Copy the absolute path
org.primefaces.extensions.showcase.util.CustomExporterFactory in
ExporterFactory file.
Step 4: Copy the exporter implementations and
add your own changes.And call these custom implementations(Ex
PDFCustomExporter,ExcelCustomExporter) instead built-in
implmentations(Ex PDFExporter,ExcelExporter)