How can I add a row that calculates all the rows above:
something like this.
tnx
Discussion posts and replies are publicly visible
In the read only grid, its a bit tricky as you have to modify the data property. But if you can switch to an editable grid, then you can just create a gridRowLayout() outside the loop to show the sum using sum() function and passing the relevant property from the variable that you are iterating on.
Try to Append the map of Sum and use it on grid.