Bug 314631 Cann't get correct default values for parameters that with non-constant default value expressions
Steps to reproduce: 1. create a report with a scalar parameter that has non-constant default value expression such as BirtDateTime.today() 2. setup a project to get the default values of the parameter in BIRT runtime Eg. IReportEngine engine = createReportEngine( ); IRunnable runnable = engine.openReportDesign( REPORT_DESIGN ); IGetParamaterDefinitionTask task = engine.createGetParameterDefinitionTask( runnable ); HashMap result = task.getDefaultValues(); Expect result: The result map contains a parameter name and default value pair in which the default value is a Date instance of today. Actural result: The default value is null.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/GetParameterDefinitionTask.java
*            the cascading parameter group name
	 * @param groupKeyValues -
	 *            the array of known parameter values (see the example above)
	 * @return the selection list of the parameter to work on
	 */
	public Collection getSelectionListForCascadingGroup(
			String parameterGroupName, Object[] groupKeyValues )
	{
		CascadingParameterGroupHandle parameterGroup = getCascadingParameterGroup( parameterGroupName );
		if ( parameterGroup == null )
		{
			executionContext.addException( new EngineException(
					MessageConstants.PARAMETER_GROUP_ISNOT_FOUND_BY_GROUPNAME_EXCEPTION,
					parameterGroupName ) );
			return Collections.EMPTY_LIST;
		}
		SlotHandle slotHandle = parameterGroup.getParameters( );
		if ( groupKeyValues.length >= slotHandle.getCount( ) )
		{
			executionContext.addException( new EngineException(
					MessageConstants.PARAMETER_INVALID_GROUP_LEVEL_EXCEPTION,
					parameterGroupName ) );
			return Collections.EMPTY_LIST;
		}
		ScalarParameterHandle requestedParam = (ScalarParameterHandle) slotHandle
				.get( groupKeyValues.length ); 
		
		
		if ( requestedParam == null )
		{