Updating One Field from Another. Easy Customization.

Hi Everyone.

One of the most often called customization requests is to default (or update) a Field A, based on what was entered in a Field B. And now its time for me to post a memo article on standard technique for this customization.

Lets define a scope of work:

1. When we issue an invoice to a customer.
2. And then select a Project used by this customer.
3. We have to default a Customer Ref Number field with a Project Purchase Order Number.
4. Which is, in its own case, an Attribute of a Project, and has to be retrieved from there.
5. PO Number is defined in Project Module "Attributes" screen and entered into a "Project" Maintenance screen.

Something like this:

In the video below I comment on customization done. Please find the code for the customization below.

Here is the code:

using System;
using System.Collections;
using System.Collections.Generic;
using PX.Data;
using PX.Objects.GL;
using PX.Objects.CM;
using PX.Objects.CS;
using PX.Objects.CR;
using PX.Objects.TX;
using PX.Objects.IN;
using PX.Objects.BQLConstants;
using PX.Objects.EP;
using PX.TM;
using SOInvoice = PX.Objects.SO.SOInvoice;
using SOInvoiceEntry = PX.Objects.SO.SOInvoiceEntry;
using PX.Objects.SO;
using PX.Objects.DR;
using PX.Objects;
using PX.Objects.AR;
using PX.Objects.PM;

namespace PX.Objects.AR
{
  [PXCustomization]
  public class Cst_ARInvoiceEntry: ARInvoiceEntry
  {

    #region Event Handlers
protected override void ARInvoice_ProjectID_FieldUpdated(PXCache sender, PXFieldUpdatedEventArgs e)
{
  base.ARInvoice_ProjectID_FieldUpdated(sender, e);
  var row = (ARInvoice)e.Row;
  var ProjectID = row.ProjectID;
  var CustRefNbr = row.InvoiceNbr;
  string EntityType = "PR";
  string Attribute = "PONUMBER";
  //CustRefNbr = CustRefNbr + 1;
     
  PMProject pm = PXSelect<PMProject,
             Where<PMProject.baseType, Equal<PMProject.ProjectBaseType>, And<PMProject.nonProject, Equal<False>, And<PMProject.contractID, Equal<Current<ARInvoice.projectID>>, And<PMProject.isTemplate, NotEqual<True>>>>>>.SelectSingleBound(this, new object [] { e.Row });
  
  if (pm != null)
  {
  //CustRefNbr = pm.ContractCD;

  PXResultset<CSAnswers> res = PXSelectJoin<CSAnswers,
       InnerJoin<CSAttribute, On<CSAttribute.attributeID, Equal<CSAnswers.attributeID>>>,
       Where<CSAnswers.entityType, Equal<Required<CSAnswers.entityType>>,
       And<CSAnswers.attributeID, Equal<Required<CSAnswers.attributeID>>,
       And<CSAnswers.entityID, Equal<Required<CSAnswers.entityID>>>>>>.Select(this, EntityType, Attribute, pm.ContractID);
  
  CSAnswers ans = res;

  if (ans.Value != null)
  {
    
  //CustRefNbr = ans.Value;

  ARInvoice line = sender.CreateCopy(row) as ARInvoice;
  line.InvoiceNbr = ans.Value;
  sender.Update(line);
  //string msg = CustRefNbr;
  //throw new PXSetPropertyException(msg);
  //row.InvoiceNbr = CustRefNbr;
}}}


    #endregion

  }


}

All the best,
Sergey.