Can't undestand why this won't work with subreports

[bthale]

We are using a framework that we have written that makes it hard to pass in a data source for a subreport. So I created a variable of type JRBeanCollectionDataSource. I have a scriptlet that overrides beforeDetailEval. See code below:

When I set a break point in this method, I can see the correct data being retrieved and passed to the variable, but debug console outpupt shows no data being passed and subreport is empty. What could cause this behaviour? The jrxml specific code is here.

<variable name="SUB_REPORT_DATA_SOURCE" class="net.sf.jasperreports.engine.data.JRBeanCollectionDataSource"/>     

<subreport>
    <reportElement x="0" y="9" width="802" height="41"/>
    <dataSourceExpression><![CDATA[$V{SUB_REPORT_DATA_SOURCE}]]></dataSourceExpression>
    <subreportExpression class="java.lang.String"><![CDATA[$P{SUBREPORT_DIR} + "TradeUpdatesSubreport.jasper"]]></subreportExpression>
   </subreport>
 

 

 

Code:

    public void beforeDetailEval() throws JRScriptletException    {	JRBeanCollectionDataSource ds = (JRBeanCollectionDataSource)this.getParameterValue("REPORT_DATA_SOURCE");	this.setVariableValue("SUB_REPORT_DATA_SOURCE", ds);    }

Post Edited by bthale at 04/04/2011 20:48

[tmatyashovsky]

Hi,

 

Sub reports are evaluated before code you've provided.

So first data source (which is empty or null at that moment) is passed to subreport and only after it is populated during beforeDetailEval() execution.

 

Why you not use pure report parameter for your data source, populate it on back-end of your application and then simply pass it to sub report?

 

Best,

Taras