Hierarchical table columns

Traditionally tables support a flat list of columns. Currently also TTableControl and TWebSiteTable are implemented this way. However, a future feature of a table control might be to support hierarchical table columns.

In a table control with hierarchical table columns a column can be expanded and collapsed just like a node in a tree control. When expanding a column new columns will appear that subdivide the information in a column just like a table does for a list. These extra columns can then be used to sort and filter the rows in the table.

The hierarchical columns could be used for the following purposes.

References to other objects

Being able to expand columns could be useful when a column references an other object. That object probably has its own properties so the object's values for those columns could be expanded in the table row.

Date values

When a column contains date values it can be very useful to be able the expand the column into the year, month and day columns. This way the user is able to not only sort on the entire date but also on individual values making up the date.