Bug 180864 Change Allow Null option in Cascading Group.[0705]
Description: Change Allow Null option in Cascading Group. Build number:2.2.0.v20070404 Steps to reproduce: 1. New a cascading group and add sub parameter. Expected result: Is Required option in cascading group definition dialog. Actual result: Allow null value option in Cascading Group definition dialog Error log:N/A
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/CascadingParametersDialog.java
}
	private String[] getDataSetColumns( ScalarParameterHandle handle,
			boolean needFilter )
	{
		DataSetHandle dataSet = getDataSet( handle );
		if ( dataSet == null )
		{
			return new String[0];
		}
		CachedMetaDataHandle metaHandle = dataSet.getCachedMetaDataHandle( );
		if ( metaHandle == null )
		{
			try
			{
				metaHandle = DataSetUIUtil.getCachedMetaDataHandle( dataSet );
			}
			catch ( SemanticException e )
			{
				ExceptionHandler.handle( e );
				return new String[0];
			}
		}
		if ( metaHandle == null || metaHandle.getResultSet( ) == null )
		{
			return new String[0];
		}
		ArrayList valueList = new ArrayList( );
		for ( Iterator iter = metaHandle.getResultSet( ).iterator( ); iter.hasNext( ); )
		{
			ResultSetColumnHandle columnHandle = (ResultSetColumnHandle) iter.next( );