custom data validation in a VBA form - forms

Question

I have this form to enter new data to a table.
I would like to warn the user when he is entering an invoice number that already exist. Here is the code I have but its not working:
Private Sub CommandButton1_Click()
Dim L As Long
Dim Code As String
Dim TextBox2 As Long
Dim valFormula As String
valFormula = "=COUNTIFS($F12:$F1702,F1702,$D12:$D1702,D1702)=1"
If MsgBox("Confirm?", vbYesNo, "Confirming new invoice") = vbYes Then
With Worksheets("FACTURE")
L = Sheets("FACTURE").Range("D65535").End(xlUp).Row + 1 'Pour placer le nouvel enregistrement _ la premi_re ligne de tableau non vide
End With
With Me
Range("D" & L).Validation
.Add Type:=xlValidateCustom, _
AlertStyle:=xlValidAlertWarning, _
Formula1:="=COUNTIFS($F12:$F1702,F1702,$D12:$D1702,D1702)=1"
.InputTitle = ""
.ErrorTitle = "Duplicate alert"
.InputMessage = ""
.ErrorMessage = "This invoice number already exist. Continue?"
Range("B" & L).Value = .ComboBox2 & .ComboBox3
Range("C" & L).Value = (Now)
Range("D" & L).Value = .TextBox2
Range("E" & L).Value = .TextBox3
Range("F" & L).Value = .TextBox4
Range("G" & L).Value = .TextBox5
Range("K" & L).Value = .ComboBox1
Range("L" & L).Value = .ComboBox2
Range("M" & L).Value = .ComboBox3
Range("N" & L).Value = .TextBox9
Range("O" & L).Value = .TextBox10
Range("R" & L).Value = .TextBox39
Range("P" & L).Value = .TextBox40
Range("C" & L).Interior.ColorIndex = 0
If .OptionButton1 Then
FormatCell Range("B" & L), xlThemeColorAccent3
ElseIf .OptionButton2 Then
FormatCell Range("B" & L), xlThemeColorAccent1
ElseIf .OptionButton3 Then
FormatCell Range("B" & L), xlThemeColorAccent4
Else
FormatCell Range("B" & L), xlThemeColorAccent2
End If
End With
End If
End Sub
Any advice?

Answer 1

As Comintern suggested, use Find() method of Range object, with code like:
Set f = rngToSerachIn.Find(what:=factureNo, LookIn:=xlValues, lookat:=xlWhole)
where
f is a range variable where to store the range with the searched value
rngToSerachIn is the range where to search the value
factureNo is the value to search for
furthermore it seems to me your invoices will be stored in rows from 12 downwards, so it could be useful to write a generic function to get first empty cell in a given column of a given worksheet ranging from a certain row
Since it'd be a good practice to demand specific tasks to Sub/Function to improve both code readability and maintenance, you could do that for:
getting first empty row after last non empty one starting from a given row in a given column of a given worksheet
validating invoice number
filling worksheet ranges
formatting invoice cell
as follows:
Option Explicit
Private Sub CommandButton1_Click()
Dim L As Long
Dim factureWs As Worksheet
If MsgBox("Confirm?", vbYesNo, "Confirming new invoice") = vbNo Then Exit Sub
Set factureWs = Worksheets("FACTURE") '<--| set the worksheet you want to work with
L = GetLastNonEmptyRow(factureWs, "D", 12) + 1 '<--| get passed worksheet first empty row after last non empty one in column "D" from row 12 (included)
If L > 12 Then If Not CheckDuplicate(Me.TextBox2, factureWs.Range("D12:D" & L - 1)) Then Exit Sub '<--| exit if duplicated non accepted by the user
FillRanges factureWs, L '<--| fill worksheet ranges with userfom controls values
FormatInvoice factureWs.Range("B" & L) '<--| color invoice cell depending on option buttons values
End Sub
Function GetLastNonEmptyRow(ws As Worksheet, colIndex As String, firstRow As Long) As Long
Dim lastRow As Long
With ws
lastRow = .Cells(.Rows.Count, colIndex).End(xlUp).row ' <--| get last non empty row in given column
If lastRow = 1 Then If IsEmpty(.Range(colIndex & 1)) Then lastRow = 0 '<--| handle the case of an empty column
If lastRow < firstRow Then lastRow = firstRow - 1 '<--| handle the case the last non empty row is above the first passed one
End With
GetLastNonEmptyRow = lastRow
End Function
Function CheckDuplicate(factureNo As String, rng As Range) As Boolean
Dim f As Range
Set f = rng.Find(what:=factureNo, LookIn:=xlValues, lookat:=xlWhole)
If Not f Is Nothing Then
CheckDuplicate = MsgBox("This invoice number already exist!" & vbCrLf & vbCrLf & "Continue?", vbExclamation + vbYesNo, "Duplicate alert") = vbYes
Else
CheckDuplicate = True
End If
End Function
Sub FormatInvoice(rng As Range)
Dim thColor As XlThemeColor
With Me
Select Case True
Case .OptionButton1
thColor = xlThemeColorAccent3
Case .OptionButton2
thColor = xlThemeColorAccent1
Case .OptionButton3
thColor = xlThemeColorAccent4
Case Else
thColor = xlThemeColorAccent2
End Select
End With
FormatCell rng, thColor
End Sub
Sub FillRanges(ws As Worksheet, L As Long)
With ws
.Range("C" & L).Value = (Now)
.Range("D" & L).Value = Me.TextBox2
.Range("E" & L).Value = Me.TextBox3
.Range("F" & L).Value = Me.TextBox4
.Range("G" & L).Value = Me.TextBox5
.Range("K" & L).Value = Me.ComboBox1
.Range("L" & L).Value = Me.ComboBox2
.Range("M" & L).Value = Me.ComboBox3
.Range("N" & L).Value = Me.TextBox9
.Range("O" & L).Value = Me.TextBox10
.Range("R" & L).Value = Me.TextBox39
.Range("P" & L).Value = Me.TextBox40
End With
End Sub
you may find it useful and follow this pattern in your subsequent coding