MS ACCESS: VBA too fast leading to field updating only if Toggle Breakpoint in code, need timer? - vba

Question

I am currently doing a Purchase Order "software" under Access and I am having issue with calculating the amount after a item quantity (qty) update.
When I have Toggle breakpoints in my VBA code on the "after update" event, after updating qty = 5 and going through the lines of code, I have the parent text field correctly updated from the subform one (which is the sum of the 'Total Price' fields).
The code contains a Refresh in order to add the right value rather than the old one:
.
.
However, when I remove the toggle breakpoint, I think that the VBA code does not have enough time fully process the refresh command, which update the parent text field with the wrong (old) value.
This issue leads to have a discrepancy between the actual subform calculated total, and the value added to the parent table (here I removed the toggle breakpoint, and added 1 on the second line item, but the calculation gave a 250 rather than a 251):
When I look at the values in the code, when the breakpoint is on the updating line, you can see that the value of the field is the right one, but the 'watch' field shows the old value:
.
.
Do you guys have a solution to make sure all the fields are updated before going to the next line?
I was thinking using some sort of delay, or an "application wait until processing done" type of command but I cannot find anything that is actually working;
Let me know,
Cheers!
EDIT 1:
The "Expected Total Cost" is bound to a table field called "curPOExpectedTotalCost", which is why I use VBA code to populate the data into its dedicated textbox (called "txtcurPOExpectedTotalCost").
The main goal is simply to have this bound field being correctly updated; I want to be able to change the qty or the unit price and automatically populate the right total PO price into "Expected Total Cost" which is bound to a table; the issue is that it works well when I am running each lines one by one using the breakpoints in my code, but does not work when I remove them; this tells me it is probably too fast, hence a way of delaying the next command or a command to wait for processing to be done.
EDIT 2:
I found a workaround, but it seems overpowered for this simple task I was trying to achieve; good side is that it removes the middle man (the subform textbox that sum all the total prices):
I open a recordset and iterate a variable until I can populate the result into the dedicated "Expected Total Cost" bound textbox:
DoCmd.RunCommand (acCmdRefresh)
Dim RS As DAO.Recordset
Dim SQL As String
SQL = "SELECT numPONumberAndRevID, numPOContentQtyOrdered, numPOContentPrice FROM tblPOSCONTENT WHERE numPONumberAndRevID = " & Nz(Me.Parent.MasterPOID.Value)
Set RS = CurrentDb.OpenRecordset(SQL)
Do While Not RS.EOF
ExpectedCalculatedCost = ExpectedCalculatedCost + RS("numPOContentQtyOrdered") * RS("numPOContentPrice")
RS.MoveNext
Loop
RS.Close
Set RS = Nothing
Me.Parent.txtcurPOExpectedTotalCost.Value = ExpectedCalculatedCost

Answer 1

We could arrange in a simple way.
We name the detail input subform control as sfrmDetail, the main total control can be assigned with a .ControlSource like:
Me.txtcurPOExpectedTotalCost.ControlSource="=[sfrmDetail].[Form].[txtSubFormExpectedTotalCost]"
When txtnumPOContentQtyOrdered updates, your main form changes instanteneously without any VBA code.
In the subform, say sfrmDetail, that will be embedded in the main form as subformcontrol sfrmDetail (yes with the same name), we assign a .ControlSouce=Sum(Qty*UnitPrice) for the control txtSubFormExpectedTotalCost, at the footer of the subform.
Solution II:
As #June7 pointed out in comments, the Total cost, that can be calculated dynamically, should be better only for display only (form input display, report printing, but not saved in disk).
OK, now we want at any cost to stock in field tblMain.curPOExpectedTotalCost the total cost with a slight data redundancy, so in the main form we have Me.txtcurPOExpectedTotalCost.ControlSource="curPOExpectedTotalCost"
In the subform sfrmDetail, we can update with:
Option Compare Database
Option Explicit
Private Sub txtnumPOContentQtyOrdered_AfterUpdate()
Me.Recalc
Me.Parent.txtcurPOExpectedTotalCost.Value = Me.txtSubformExpectedTotalCost.Value
End Sub
Me.Recalc() updates all calculated fields of sfrmDetail before we change the target main table field.
Please consult also Is storing counts of database record redundant? for data redundancy.