Footer sum based on a more complex situation (another columns, value signs, ...)

itajackass

My goal is to do a more complex sum based on another column:
Details:

This is the flow i'd like to do:

1. var $SUM = 0;
2. If column Type == IN then:
   2.1 IF AMOUNT > 0 THEN $sum = $sum + AMOUNT; ELSE $sum = $sum - AMOUNT;
   3 If column Type == OUT then:
   3.1 IF AMOUNT > 0 THEN $sum = $sum - AMOUNT; ELSE $sum = $sum + AMOUNT;

So this is i'm expecting:
$sum = 0;
$sum = $sum + 200;
$sum = $sum + 100;
$sum = $sum - 50;
$sum = $sum -10;

//$sum now is: 240 (i'd like to have this result) instead 340.

This is my example fiddle: http://live.datatables.net/togejizi/1/edit

If it possible i'd like to use data-in attribute i've inserted for each cell.

itajackass

I've tried this working solution.

http://live.datatables.net/liravimi/1/edit

But i'll ask for a better solution if is possible?