Populating unbound column with fix value reference to other table - acumatica

Question

I have extended a APTran DAC for Bills and Adjustments screen (ID - AP301000).
I am trying to populate a value from different table based on the current line item.
The value I need is from CrossReference based on current Inventory on line item and VendorID of current Bill.
Below is the code. Please let me know if I am missing anything.
public class string_VendorType : Constant<string>
{
public string_VendorType() : base("0VPN")
{ }
}
protected string _UsrVendorPartNum;
[PXString(50)]
[PXUIField(DisplayName = "Vendor Part Number", Enabled = false, IsReadOnly = true)]
[PXDefault(typeof(Search2<INItemXRef.alternateID,
LeftJoin<InventoryItem, On<INItemXRef.inventoryID, Equal<InventoryItem.inventoryID>>,
LeftJoin<APTran, On<InventoryItem.inventoryID, Equal<APTran.inventoryID>>,
LeftJoin<APInvoice, On<APInvoice.refNbr, Equal<APTran.refNbr>,
And<APInvoice.vendorID, Equal<INItemXRef.bAccountID>>>>>>,
Where<InventoryItem.inventoryID, Equal<Current<APTran.inventoryID>>,
And<INItemXRef.alternateType, Equal<string_VendorType>,
And<APInvoice.refNbr, Equal<Current<APTran.refNbr>>>>>>))]
public virtual string UsrVendorPartNum
{
get
{
return _UsrVendorPartNum;
}
set
{
_UsrVendorPartNum = value;
}
}
public abstract class usrVendorPartNum : IBqlField { }
However, the value isn't populating. Please advise.

Answer 1

I got the following working (using PXUnboundDefault). The query you have can be simplified to the following working example:
public class APTranExt : PXCacheExtension<PX.Objects.AP.APTran>
{
protected string _UsrVendorPartNum;
[PXString(50)]
[PXUIField(DisplayName = "Vendor Part Number", Enabled = false, IsReadOnly = true)]
[PXUnboundDefault(typeof(Search<INItemXRef.alternateID,
Where<INItemXRef.inventoryID, Equal<Current<APTran.inventoryID>>,
And<INItemXRef.alternateType, Equal<INAlternateType.vPN>,
And<INItemXRef.bAccountID, Equal<Current<APTran.vendorID>>>>>>))]
public virtual string UsrVendorPartNum
{
get
{
return _UsrVendorPartNum;
}
set
{
_UsrVendorPartNum = value;
}
}
public abstract class usrVendorPartNum : IBqlField { }
}
Note that you do not need to create your own constant. You can reuse INAlternateType and the vPN constant.
Simply for reference...
I would say if this was a DB field you could look into using the AlternativeItemAttribute, however it requires a subitem field which oddly APTran does not have in it.
Example usage of AlternativeItemAttribute on POLine.AlternateID:
public abstract class alternateID : PX.Data.IBqlField
{
}
protected String _AlternateID;
[AlternativeItem(INPrimaryAlternateType.VPN, typeof(POLine.vendorID), typeof(POLine.inventoryID), typeof(POLine.subItemID))]
public virtual String AlternateID
{
get
{
return this._AlternateID;
}
set
{
this._AlternateID = value;
}
}