tree hierarchy in column for advaced data grid in flex

Question

I am creating a dynamic advanced data grid and want to have show parent child hierarchy in columns of the datagrid i.e. when i click on a particular column header of a datagrid it should expand horizontally showing all its children as below

Before Clicking on ColumnHeader1

+ColumnHeader1

After Clicking on ColumnHeader1

-ColumnHeader1 Column1 Column2 Column3

any idea/sample on how to achieve this would be helpful

Answer 1

I have tried something like this and it works:

put your data in:

public var targetSchema:HierarchicalData = null;

and