Why couldn't you use a Column-Post Validate event on the ItemCode field to fill the PO No. field for your conditions. It would only fire once per ItemCode and not when otherwise changing the line. 

Why couldn't you use a Column-Post Validate event on the ItemCode field to fill the PO No. field for your conditions. It would only fire once per ItemCode and not when otherwise changing the line. 

connex Sorry but I am not following you on this code wise.

I said you can't prevent an event script from running more than once, but what connex is suggesting is using an event trigger (column post-validate on ItemCode) that naturally will only run once per line.  After you set a line's ItemCode, it never changes.

If your business logic can be properly applied at that point, it is an excellent idea, and easier than the checkbox.

I simplified the script without the checkbox and it populates the purchaseorderno field with the "C", however it does it no matter the customerno, so I have something wrong there.  Also curious on if I want the "C" value to be set only if a PO is not created, the column post-validate with this script fires off right after you enter the item code, I would think we would need it to look at the field after the record was written, gives the user a chance to create a PO if needed without going and deleting the "C".

If oSession.CompanyCode = "ROI" then

nCustomerNo = ""
nVendorno = ""
nPOno = ""

rVal = oBusObj.GetValue("CustomerNo$", nCustomerNo)
rVal = oBusObj.GetValue("VendorNo$", nVendorNo)
rVal = oBusObj.GetValue("PurchaseOrderNo$", nPOno)

	If nCustomerNo <> "2861000" or "2303006" then

		If nVendorno = "0001226" then		

			If nPOno = "" then			
			rVal = oBusObj.SetValue("PurchaseOrderNo$", "C")
			
			End if	
		End if
	End if
End if

The business process is up to you.  For a pre-write event on the detail table you'd need the checkbox for control.

Use oHeaderObj for your GetValue on CustomerNo (since it is a header field).

Your filter on nCustomerNo is all wrong (and I'm surprised you don't get a VBScript syntax error).  Try something like this:

variable <> "A" and variable <> "B"

Column Post Validate on ItemCode should work if on a version that allows selecting it (older versions didn't but I think 2020+ does in a detail script).

A table Post Read event filtered by oBusObj.EditState = 2 also works and once the record is saved, the EditState will be equal to 1.

Another event could be the Set Default Values one, I haven't used it much but it is supposed to run when default values are being set by the business object on new records.

Column Post-Validate is in every version since script events were introduced in 2010 with version 4.40. I think it is your safest bet because any event that precedes setting the ItemCode will cause the PO number field to be cleared.

The event existed since 4.4 but in certain tables, certain columns were not selectable on column events.  I seem to recall at one point, the ItemCode column could not be selected on detail tables.  I can't recall what version was the last version I saw this on though, I did just check my 2018 install and it can be selected so it may have been corrected in 2018 or maybe 2017.

Column-Post Validate and table pre-write both work good in every aspect except the script puts the "C" value in the PO field as soon as the item code is entered, I would like it to wait until the user decides if they want to generate a PO first.  Also tried the table post read with the "editstate" filter, couldn't get the script to fire at all.  Seems like I am close with the first two events maybe just a logic sequence problem?  Here's the corrected script Kevin M .

If oSession.CompanyCode = "ROI" then

sCCheckBox = ""
nCustomerNo = ""
nVendorno = ""
nPOno = ""

rVal = oBusObj.GetValue("UDF_CCHECKBOX$", sCCheckBox)
rVal = oHeaderObj.GetValue("CustomerNo$", nCustomerNo)
rVal = oBusObj.GetValue("VendorNo$", nVendorNo)
rVal = oBusObj.GetValue("PurchaseOrderNo$", nPOno)

	If sCCheckbox = "N" then

		If nCustomerNo <> "2861000" and nCustomerNo <> "2303006" then

			If nVendorno = "0001226" then		

				If nPOno = "" then			
				rVal = oBusObj.SetValue("PurchaseOrderNo$", "C")
				rVal = oBusObj.SetValue("UDF_CCHECKBOX$", "Y")
				
				End if
			End if	
		End if
	End if
End if

If you want to give the user an opportunity to create a PO first, then a line level script is not the way to do this.  You'll want to switch to the pre-write event on the header table.  Grab the customer number and if appropriate, loop through each line using the same criteria against the checkbox and purchase order number and for each line that meets your criteria, set the purchase order number.  You can restrict this to new records only by checking if oBusObj.EditState = 2 so it doesn't run on existing orders.

Remove the column trigger, and just leave the line pre-write.  They'd have to add the value before moving off the line for the first time, but that is the best you can do in a line script.

David,

I always recommend use of pre-totals for header scripts instead of pre-write, since $ changes in a header pre-write script cause serious problems.