Recalculation of attributes

Question

Hi,
In a view object I have the attributes (amount, balance, and others) from entities objects and the following case in a page:
amount [input text] (where the user enters a number)
balance [output text] (where balance is a atribute that must be recalculated, to get it I use partialTriggers and autoSubmit in amount inputText ) (The recalculation is: balance=balance - amount)
To get the balance in the value type selecting Expressions of attribute 'balance' I enter the following:
((balance == null)? 0 : balance) - ((amount == null)? 0 : amount), in Dependencies I could only choose amount attribute and not balance attribute because does not appear as available.
Testing the page appears the value current of the attribute 'balance' and entering a number in amount input text, does not appears the recalculated value in the balance. What should I do to get the value recalculated and then update this new value?
Edited by: user10469853 on 08/12/2008 06:20

Answer 1

Hi,
== null is not valid in EL, use the "empty" operator instead:
(empty balance ? 0 : balance) - (empty amount ? 0 : amount)
Also, the partial trigger goes on the balance field, not on the inputText, from your post I think you might have made that mistake.
Regards,
~ Simon