Hello :
I need advice on how to proceed :

Given a table 6 x 30 rows. A typical row as follows :

Cell A (text) - Cell B (text) - Cell C (checkbox) - Cell D (number) -
Cell E (number) - Cell F (if C = true, D * E else O)

Cell F contains a Sub-Total for that row.
Cell F(n) contains the grand total - Sum of Cells F1 to Fn-1

The Ruby code does the following ;
1  If a checkbox is changed, calculate value of Cell F in the same row
and update the contents of the field.
However, Ruby would need to check constantly the status of each
checkbox. This sounds like a bad way to do this. Ideally, on change, the
checkbox would send a message to Ruby, but how?.

2  Update the value of Cell F(n)
(Cell F names could be numeric 1 to n-1 so Ruby could loop through and
sum the list)

I suppose the Sub-Total cells and the Grand Total cell would contain an
ERB : <% calculated value %>

However, I don”Ēt see how the ERBs in Sub-Total/Grand Total could update
the table once the page has been rendered.

If item 1 above isn”Ēt possible, the page could remain dormant until the
user clicks on a button to calculate the Grand Total.

I have the table. However, I don”Ēt know where to begin with Ruby.(I”Ēm
doing this in RubyFrontier).

Regards : Hubert Wagner