Script Cross-tab in BIRT 2.2

I failed to find out how to add column name for a ’dimension’ in cross-tab item of BIRT 2.2, so I have to use scripts to create a cross-table. The idea here is creating table columns before the create table event。
(You may notice that the top-left part of the cross-tab in BIRT 2.2 is blank and could not add any other report items into it. It’s confused!??)

importPackage(Packages.org.eclipse.birt.report.model.api);  
  
// invode a java object to get all 'usTitles' datas from Database.  
usTitleService = new Packages.com.boldtech.seed.util.ReportUsTitleUtil;  
usTitles = usTitleService.getUsTitles();  
  
reportDesignHandle = reportContext.getReportRunnable().designHandle.getDesignHandle();  
reportEngine = reportContext.getReportRunnable().reportEngine;  
elementFactory = reportDesignHandle.getElementFactory();  
  
// a table in the report body  
employeeTable = reportDesignHandle.getBody().getContents().get(0);  
header = employeeTable.getHeader().get(0);  
detail = employeeTable.getDetail().get(0);  
footer = employeeTable.getFooter().get(0);  
group = employeeTable.getGroups().get(0);  
groupFooter = group.getFooter().get(0);  
computedSet = employeeTable.getColumnBindings();  
  
usTitleSize = usTitles.size();  
var startAddColumn = 2;  
for(var i=0; i < usTitleSize; i++){  
//--- column title  
var addedColumn = startAddColumn + i;  
employeeTable.insertColumn(addedColumn,1);  
cell = header.getCells().get(addedColumn);  
cell.getWidth().setValue("10%");  
label = elementFactory.newLabel(null);  
cell.getContent().add(label);  
label.setText(usTitles.get(i).getSysConfigName());  
  
//--- column value  
// "employeeTitleResult" was created to keep metric values in the 'onFetch' event of table  
cs1 = StructureFactory.createComputedColumn();  
cs1.setName("Column_TitleCount_" + i);  
cs1.setExpression("employeeTitleResult[row.__rownum][" + i + "].value");  
cs1.setDataType("any");  
computedSet.addItem( cs1 );  
  
cell = detail.getCells().get(addedColumn);  
data = elementFactory.newDataItem(null);  
data.setResultSetColumn("Column_TitleCount_" + i);  
data.setName("ColumnValue_" + i);  
data.setStyleName("cell-text-center-align");  
cell.getContent().add(data);  
  
//--- summary at group footer cell  
cs1 = StructureFactory.createComputedColumn();  
cs1.setName("Group_TitleCount_" + i);  
cs1.setAggregateFunction("SUM");  
cs1.setExpression("row[\"Column_TitleCount_" + i + "\"]");  
cs1.setFilterExpression("row[\"Column_TitleCount_" + i + "\"]>=1");  
cs1.setDataType("any");  
cs1.setAggregateOn("ProjectGroup");  
computedSet.addItem( cs1 );  
  
cell = groupFooter.getCells().get(addedColumn);  
data = elementFactory.newDataItem( null );  
data.setResultSetColumn("Group_TitleCount_"+i);  
data.setName("GroupValue_" + i);  
data.setStyleName("cell-text-center-align");  
cell.getContent().add(data);  
// group summary rule: do not display '0' value.  
cs1 = StructureFactory.createMapRule();  
cs1.setTestExpression("row[\"Group_TitleCount_" + i + "\"]");  
cs1.setOperator("le");  
cs1.setValue1("0");  
data.getPropertyHandle("mapRules").addItem(cs1);  
  
//--- summary at footer cell  
cs1 = StructureFactory.createComputedColumn();  
cs1.setName("Grand_TitleCount_" + i);  
cs1.setAggregateFunction("SUM");  
cs1.setExpression("row[\"Group_TitleCount_" + i + "\"]");  
cs1.setFilterExpression("row[\"Group_TitleCount_" + i + "\"]>=1");  
cs1.setDataType("any");  
computedSet.addItem( cs1 );  
  
cell = footer.getCells().get(addedColumn);  
data = elementFactory.newDataItem( null );  
data.setResultSetColumn("Grand_TitleCount_" + i);  
data.setName("GrandValue_" + i);  
data.setStyleName("cell-text-center-align");  
cell.getContent().add(data);  
  
// footer summary rule: do not display '0' value.  
cs1 = StructureFactory.createMapRule();  
cs1.setTestExpression("row[\"Grand_TitleCount_" + i + "\"]");  
cs1.setOperator("le");  
cs1.setValue1("0");  
data.getPropertyHandle("mapRules").addItem(cs1);  
}