Bug 176457 Use container's column bindings in chart editor
chart/org.eclipse.birt.chart.reportitem.ui/src/org/eclipse/birt/chart/reportitem/ui/ReportDataServiceProvider.java
return itemHandle.columnBindingsIterator( );
	}
	protected final List getPreviewRowData( String[] columnExpression,
			int rowCount, boolean isStringType ) throws ChartException
	{
		ArrayList dataList = new ArrayList( );
		
		
		ClassLoader oldContextLoader = Thread.currentThread( )
				.getContextClassLoader( );
		ClassLoader parentLoader = oldContextLoader;
		if ( parentLoader == null )
			parentLoader = this.getClass( ).getClassLoader( );
		ClassLoader newContextLoader = getCustomScriptClassLoader( parentLoader );
		Thread.currentThread( ).setContextClassLoader( newContextLoader );
		try
		{
			QueryDefinition queryDefn = new QueryDefinition( );
			queryDefn.setMaxRows( getMaxRow( ) );
			queryDefn.setDataSetName( getDataSetFromHandle( ).getQualifiedName( ) );
			DataRequestSession session = DataRequestSession.newSession( new DataSessionContext( DataSessionContext.CACHE_USE_ALWAYS,
					getReportDesignHandle( ) ) );
			for ( int i = 0; i < columnExpression.length; i++ )
			{
				queryDefn.addResultSetExpression( columnExpression[i],
						new ScriptExpression( columnExpression[i] ) );