My goal is to create a PDF containing all the products ordered from my orderHome page.

The problem is that the @DataModel field from the OrderHome object can be accessed from the HTML view, but not for the PDF view. I've got the following Error :

/pdf/order/printOrder.xhtml @171,62 <c:forEach items="#{orderLines}"> Must evaluate to a Collection, Map, Array, or null.

My question is : is there any problem with @DataModel (which is here in Conversation context, as its owner class) and PDF generated with <p:document/> tag ?

Here is the orderHome.xml file :

<ui:composition ... >
  ...
  <rich:dataTable value="#{orderLines}" ...>
    <rich:column ...>
      ...
    </rich:column>
  </rich:dataTable>
  <h:commandButton value="#{messages['order.print']}" action="#{OrderHome.print()}"/>
  ...
</ui:composition>

The OrderHome.java file :

@Name("orderHome")
public class OrderHome extends EntityHome<Order> {
  ...
  @DataModel
  protected List<OrderLine> orderLines;
  ...
  @Override
  protected void initInstance() {
    super.initInstance();
    initOrderProducts();
  }
  
  public void initOrderProducts() {
    orderedProducts = getInstance().getOrderLines()
  }
  
  public void print() {
    computeTotalOrder(); // specific method
  }
  
  private void computeTotalOrder() {
    double total = 0;
    for(final OrderLine orderLine : orderLines) {
      total += orderLine.getPrice();
    }
    getInstance.setTotalOrder(total);
  }
  ...
}

The orderHome.page.xml file :

<?xml ...?>
<page ...>
  <begin-conversation join="true" flush-mode="manual" />

  <navigation from-action="#{orderHome.print()}">
    <redirect view-id="/pdf/order/printOrder.xhtml"/>
  </navigation>
</page>

And finaly the printOrder.xhtml page :

<p:document ...>
  ...
  <c:forEach items="#{orderLines}" var="orderLine">
    ...
  </c:forEach>
  ...
</p:document>

I've googled for a long time and already tried to replace my <h:commandButton> with some <s:link> or <a:commandButton>, but nothing changed ...