Using recalc function to change a field if item has weight - netsuite

Question

I currently have a recalc function that resets the shipping cost field if a line item has changed, but I really only need to do that if the item has a weight. How do I retrieve the weight of the changed line item?
Here's what I currently have:
function recalc(){
nlapiSetFieldValue('shippingcost', '0.00');
}

Answer 1

recalc is fired only when a change to a line item affects the Total of the transaction, and as such, may not be a reliable event for what you want to accomplish.
I would recommend against using validateLine as that event should be used to determine whether the new value for a field is valid.
I would advise you to use fieldChanged for responding to a field value that has changed. Something like:
function fieldChanged(type, name, linenum) {
if (type == 'item') {
if (name == 'item') {
handleItemChange(linenum);
}
}
}
function handleItemChange(linenum) {
var itemWeight = parseFloat(nlapiGetFieldValue('item', 'weight', linenum)) || 0;
if (itemWeight > 0) {
nlapiSetFieldValue('shippingcost', 0);
}
}
You may also want to consider the postSourcing event instead of fieldChanged, depending on which fields should actually trigger this logic.

Answer 2

Small segue, recalc doesn't give you a way to get the current line of the sublist, you'd need to loop through the whole sublist anytime a single line was changed.
Try validateLine, something like:
function validateLine(listType){
//To get the item weight, you could create a
//custom transaction column field that sourced the item weight.
if(nlapiGetCurrentLineItemValue(listType,'custcolitemWeight') > 0){
nlapiSetFieldValue('shippingcost','0.00')
}
//or you could source directly from the item record using nlapiLookupField
// Depending on your use case either could be appropriate
if(nlapiLookupField('item',nlapiGetCurrentLineItemValue(listType,'item'),'weight')){
nlapiSetFieldValue('shippingcost','0.00')
}
//you *need* to return true with the validate* event functions.
return true;
}
This (untested) example only handles line additions. If users are allowed to remove items, you'll need to implement a similar validateDelete that also reverts your changes.