Calculate the sum of grid in action center

Hi All ,
I want to create task form on action center with dynamic content , I am using the new package of FormActivityLibrary(1.1.6) so i can adding logic to the components , I am able to adding java script to modify the value of text filed at runtime , but I want to iterate grid view to calculate the sum of all rows how can i do that ?

The solution is we can deal with datatable of the grid as array of arrays in js scripts .

I can execute script in preview of the form , but can’t execute it in action center !!