Below shows extensive use of value getters (using expressions) and class rules (again using expressions). The grid shows 'actual vs budget data and yearly total' for widget sales split by city and country.
Location column is showing the aggregation groups, grouping by city and country.
Months are affected by the context. The data displayed is either x_act or x_bud data for the month (eg jan_act when jan is green, or jan_bud when jan is red). Likewise the background color is also changed using class rules dependent on the selected month.
Total is the total 'actual' figures display, ie adding up all the green. This also changes (which columns to include) as the month is changed.
Notice that the example (including calculating the expression on the fly, the grid only calculates what's needed to be displayed) runs very fast (once the data is loaded) despite over 6,000 rows.
This example is best viewed by opening it in a new tab (click the link on the top right of the example).