Acumatica Unbound User Fields on SOOrder - acumatica

Question

I have a user field on an SOOrder DAC extension, which is a sum of some of the lines on the document (based on a field in the SOLine extension). When I add a new line, the total is updating properly. However, when I load the document for the first time, the screen is showing 0.00. I created an SOOrderEntry extension and I put code into the SOLine_RowSelecting event handler. When I load the document, it steps into the code and it looks like it is setting the fields properly, but they don't show on the screen. The same method is called from the SOLine_CuryLineAmt_FieldUpdated, and that works just fine. Here is the code I'm using:
public class SOOrderEntryExt : PXGraphExtension<SOOrderEntry>
{
//Used to prevent recursive calls in RowSelecting
bool _isCalculating = false;
protected virtual void SOLine_RowSelecting(PXCache cache, PXRowSelectingEventArgs e)
{
var row = e.Row as SOLine;
if (row == null) return;
using (new PXConnectionScope())
{
if (!_isCalculating)
CalcTotals();
}
}
protected virtual void SOLine_CuryLineAmt_FieldUpdated(PXCache cache, PXFieldUpdatedEventArgs e)
{
if (!_isCalculating)
CalcTotals();
}
public void CalcTotals()
{
SOOrder order = Base.CurrentDocument.Select();
if (order == null) return;
_isCalculating = true;
var orderExt = order.GetExtension<SOOrderExt>();
orderExt.UsrMyCustomField = 0m;
//Get totals
foreach (SOLine lineSum in Base.Transactions.Select())
{
var lineSumExt = lineSum.GetExtension<SOLineExt>();
if (lineSumExt.UsrMyCondition)
orderExt.UsrMyCustomField += lineSum.CuryLineAmt;
}
_isCalculating = false;
}
}

Answer 1

RowSelected is called on each callback to select the data. There's no need to re-calculate on FieldUpdated event too because RowSelected will be called when updating records. Therefore consider removing SOLine_CuryLineAmt_FieldUpdated
You have the RowSelected event declared for SOLine DAC. The event then selects all SOLine to compute the totals. This amount to when selecting one of the Detail compute the total of all Detail, that smells lack a recursive pattern. Therefore consider declaring RowSelected on the Master document which is SOOrder in this case and remove all the workarounds you have to break recursion.
There's no null check in computations. Acumatica DAC fields are nullable. With your code you can end up in situation where you add null to a number which would results in type violation at runtime. Therefore consider checking if CuryLineAmt is null before using it's value to compute the total.
You are accumulating the total in the UsrMyCustomField DAC field
using the += addition assignment operator. It works but I would
advise against that. The DAC fields aren't meant as register for
computations or temporary value place-holder. Therefore consider
accumulating the total in a local variable and assign only the final
computed value to the DAC field.
Code to compute a total with all these points considered:
public class SOOrderEntryExt : PXGraphExtension<SOOrderEntry>
{
public void SOOrder_RowSelected(PXCache cache, PXRowSelectedEventArgs e)
{
SOOrder order = e.Row as SOOrder;
if (order != null)
{
SOOrderExt orderExt = order.GetExtension<SOOrderExt>();
if (orderExt != null)
{
decimal total = 0M;
foreach (SOLine line in Base.Transactions.Select())
{
total += line.CuryLineAmt.HasValue ? line.CuryLineAmt.Value : 0M;
}
orderExt.UsrMyCustomField = total;
}
}
}
}