Acumatica - How do I add a new column to InvoiceSplits Selector - action

Question

I need to add UnitCost to the Add Invoice Details Selector screen that appears when Add Invoice is clicked in Sales Order screen when the invoice type is a credit or return. I am new to Acumatica and not sure how I need to do it as an extension. I added it to InvoiceSplits but when I put breakpoints in there, I never hit them.
I added this code to SOOrderEntry...am I on the right track?
namespace PX.Objects.SO
{
public class SOOrderEntry_Extension : PXGraphExtension<SOOrderEntry>
{
[System.SerializableAttribute()]
public class InvoiceSplits : IBqlTable
{
#region UnitCost
public abstract class unitCost : PX.Data.IBqlField
{
}
protected Decimal? _UnitCost;
[PXDBPriceCost()]
[PXUIField(DisplayName = "Unit Cost")]
public virtual Decimal? UnitCost
{
get
{
return this._UnitCost;
}
set
{
this._UnitCost = value;
}
}
}
#endregion
#region Event Handlers
public delegate InvoiceSplits CreateInvoiceSplitsDelegate(ARTran artran, SOLine line, SOSalesPerTran sptran, INTran tran, INTranSplit split);
// [PXOverride]
public InvoiceSplits CreateInvoiceSplits(ARTran artran, SOLine line, SOSalesPerTran sptran, INTran tran, INTranSplit split, CreateInvoiceSplitsDelegate baseMethod)
{
InvoiceSplits invSplit = new InvoiceSplits();
invSplit.UnitCost = artran.UnitCost;
if (tran != null)
{
invSplit.UnitCost = split.UnitCost ?? tran.UnitCost;
}
return invSplit;
// return baseMethod(artran,line,sptran,tran,split);
}

Answer 1

Instead of creating a separate InvoiceSplits class, you would want to make a PXCacheExtension of InvoiceSplits.
public sealed class InvoiceSplitsExtension : PXCacheExtension<InvoiceSplits>
{
#region UnitCost
public abstract class unitCost : IBqlField
{
}
[PXDBPriceCost]
[PXUIField(DisplayName = "Unit Cost")]
public decimal? UnitCost { get; set; }
#endregion
}
Then in the PXOverride of the CreateInvoiceSplits method you would get the CacheExtension and set the UnitCost on that.
public delegate InvoiceSplits CreateInvoiceSplitsDel(ARTran artran, SOLine line, SOSalesPerTran sptran, INTran tran, INTranSplit split);
[PXOverride]
public InvoiceSplits CreateInvoiceSplits(ARTran artran, SOLine line, SOSalesPerTran sptran, INTran tran, INTranSplit split, CreateInvoiceSplitsDel del)
{
InvoiceSplits invSplit = del?.Invoke(artran, line, sptran, tran, split);
InvoiceSplitsExtension invSplitExt = PXCache<InvoiceSplits>.GetExtension<InvoiceSplitsExtension>(invSplit);
invSplitExt.UnitCost = artran.UnitCost;
if (tran != null)
{
invSplitExt.UnitCost = split.UnitCost ?? tran.UnitCost;
}
return invSplit;
}
Lastly, you will need to add your UnitCost field to the UI. To do this you will need to go into a customization package, customize the SO301000 screen and navigate to Dialogs->Dialog: Add Invoice Details->Grid: invoiceSplits on the tree view. Then go to the "Add Data Fields" tab, select your UnitCost field and click create controls.