How to make the following code simpler with Arrays - ms-access

Question

This is by no means essential, but I would like to find out how to create more efficient code, and i'm sure this is far from efficient!
On the form disabled fields values are cleared before the form is saved.
The below code send a message to the user to inform them that they may lose some data if they leave a checkbox unchecked.
In the context of the form it all makes sense, i would just like to know a simpler methodology, i'm sure i could use an array somewhere but cant quite figure it out.
Dim couldLoseData As Boolean
Dim msgStr As String
couldLoseData = False
If (Me.chkInvSent = False) And (Not IsNull(Me.invoicedDate)) Then
couldLoseData = True
msgStr = "Invoice Sent"
End If
If (Me.chkFeePaid = False) And (Not IsNull(Me.datePaid)) Then
couldLoseData = True
If msgStr = "" Then
msgStr = "Claim Fee Paid"
Else
msgStr = msgStr & " / Claim Fee Paid"
End If
End If
If (Me.chkFeeLodged = False) And (Not IsNull(Me.lodgedDate)) Then
couldLoseData = True
If msgStr = "" Then
msgStr = "Fee Lodged"
Else
msgStr = msgStr & " / Fee Lodged"
End If
End If
If couldLoseData = True Then
If MsgBox("You will lose data in the following areas as the relevant checkboxes are unticked." & vbNewLine & vbNewLine & _
msgStr & vbNewLine & vbNewLine & "Do you wish to continue?", vbYesNo, dbNameOf) = vbNo Then
Cancel = True
End If
Else
'
'
'
' Procedure that gets carried out here
End If
No biggie but if any one could offer me a simpler solution it would be appreciated.
Cheers
Noel

Answer 1

I'm not sure why you think you should be using arrays. When it comes to the msgStr variable logic I would just put in the following:
msgStr = msgStr & "Invoice Sent / "
rather than the five lines of If msgstr = "" Then, etc, etc, End If lines.
Then at the end I would put in the following line
msgStr = lef(msgStr, len(msgStr) - 3) ' remove the trailing /
This then removes the trailing " / "
Purists will tell you that you should never add anything to a string you later remove. I say, so long as you leave a comment there for the next person who is reading your code, this reduces complexity of your preceding lines of code making it much easier to grasp exactly what is going on.
Whenever I'm looking for a value to be returned from a MsgBox I place the string creating in a separate line of code. Thus is much easier to see, at a glance, exactly what the code is doing.
strMsg = "You will lose data in the following areas as the relevant checkboxes are unticked." & vbNewLine & vbNewLine & _
msgStr & vbNewLine & vbNewLine & "Do you wish to continue?"
If MsgBox(strMsg, vbYesNo, dbNameOf) <> vbYes Then _
Cancel = True
If I'm only setting one value in the If statement, such as you show, I will also put in the _ and thus not require the End If.
I also prefer <> vbYes just in case something wonky should happen or if someone, not you of course, mucks with the msgbox options.

Answer 2

Why do you even allow the user to close the form when all the data fields have not been filled out?
Basically, to me, your logic is all in the wrong place. If you have a CLOSE button on your form (assuming you've gotten rid of the default Windows CLOSE X), you would not enable it until such time as all the data fields have been filled out appropriately.
The way I usually do this is to write a subroutine (or function) that checks all the fields that have to be filled out and enables the CLOSE button if everything is in order. Thus, the user CAN'T close the form until all the appropriate fields are filled out, except, perhaps, if you've provided a CANCEL button (in which case, you WANT to lose the data).

Answer 3

You don't need arrays but a simple helper method to simplify code and make it more reusable:
(just replace checkboxes and conditions in the following code)
Public Function ErrorChecker(assumption As Boolean, errorMessage As String, condition As Boolean, concatenate As Boolean) As String
Dim ret As String = [String].Empty
If Not assumption AndAlso condition Then
If concatenate Then
ret += " / "
End If
ret += errorMessage
End If
Return ret
End Function
Private Sub button1_Click(sender As Object, e As EventArgs)
Dim message As String = [String].Empty
message += ErrorChecker(checkBox1.Checked, "Error 1", value1 Is Nothing, False)
message += ErrorChecker(checkBox2.Checked, "Error 2", value2 Is Nothing, True)
message += ErrorChecker(checkBox3.Checked, "Error 3", value3 Is Nothing, True)
If message <> String.Empty Then
'messagebox
End If
End Sub

Answer 4

I've written a simple function to concatenate two strings that eliminates the need to worry about whether you need to strip anything off when you're done concatenating. Here's the function:
'-----------------------------------------------------------------------------
' Purpose : Concatenates two strings
' Usage : Dim MyList As String
' MyList = Conc(MyList, SomeValue)
' Notes : Eliminates the need to strip off the leading/trailing delimiter
' when building a string list
'-----------------------------------------------------------------------------
Function Conc(StartText As String, NextVal, _
Optional Delimiter As String = ", ") As String
If Len(StartText) = 0 Then
Conc = Nz(NextVal)
ElseIf Len(CStr(Nz(NextVal))) = 0 Then
Conc = StartText
Else
Conc = StartText & Delimiter & NextVal
End If
End Function
And here's how I'd rewrite your code using this function:
Dim msgStr As String
If (Me.chkInvSent = False) And (Not IsNull(Me.invoicedDate)) Then
msgStr = Conc(msgStr, "Invoice Sent", " / ")
End If
If (Me.chkFeePaid = False) And (Not IsNull(Me.datePaid)) Then
msgStr = Conc(msgStr, "Claim Fee Paid", " / ")
End If
If (Me.chkFeeLodged = False) And (Not IsNull(Me.lodgedDate)) Then
msgStr = Conc(msgStr, "Fee Lodged", " / ")
End If
If Len(msgStr) > 0 Then
If MsgBox("You will lose data in the following areas as the relevant checkboxes are unticked." & vbNewLine & vbNewLine & _
msgStr & vbNewLine & vbNewLine & "Do you wish to continue?", vbYesNo, dbNameOf) <> vbYes Then
Cancel = True
End If
Else
' Procedure that gets carried out here
End If

Answer 5

This is how I'd code it up
Dim couldLoseData As Boolean
Dim msgStr As String
Dim InvBoolean as boolean
Dim PaidBoolean as boolean
Dim LodgedBoolean as boolean
Dim response as integer
couldLoseData = False
InvBoolean = (Me.chkInvSent = False) And (Not IsNull(Me.invoicedDate))
PaidBoolean = (Me.chkFeePaid = False) And (Not IsNull(Me.datePaid))
LodgedBoolean = (Me.chkFeeLodged = False) And (Not IsNull(Me.lodgedDate))
couldLoseData = InvBoolean or PaidBoolean or LodgeBoolean
'if any one is true, there could be lost data.
if couldLoseData = false then
exit sub 'bail if nothing applies
'you may want a GOTO if there is stuff this sub needs to do regardless
end if
If InvBoolean = true then 'add phrase and move to new line
msgStr = msgStr & "Invoice Sent" & vbcrlf
end if
If PaidBoolean = true then 'add phrase and move to new line
msgStr = msgStr & "Claim Fee Paid" & vbcrlf
end if
If LodgedBoolean = true then 'add phrase and move to new line
msgStr = msgStr & "Fee Lodged" & vbcrlf
end if
If couldLoseData = True Then
msgStr = "You will lose data in the following areas as the relevant checkboxes are unticked." & vbcrlf & msgStr & vbcrlf
msgStr = msgStr & "Do you wish to continue?"
response = msgbox(msgstr, vbYesNo)
if response = vbno then
Cancel = True
End If
end if

Answer 6

If you really were looking to use an array:
Dim couldLoseData As Boolean
Dim msgStr As String
Dim ConditionsResponses(0 to 2,1)
Dim x as integer
Dim response as integer
couldLoseData = False
ConditionsResponses(0,0) = (Me.chkInvSent = False) And (Not IsNull(Me.invoicedDate))
ConditionsResponses(1,0) = (Me.chkFeePaid = False) And (Not IsNull(Me.datePaid))
ConditionsResponses(2,0) = (Me.chkFeeLodged = False) And (Not IsNull(Me.lodgedDate))
ConditionsResponses(0,1) = "Invoice Sent" & vbcrlf
ConditionsResponses(1,1) = "Claim Fee Paid" & vbcrlf
ConditionsResponses(2,1) = "Fee Lodged" & vbcrlf
couldLoseData = ConditionsResponses(0,0) or ConditionsResponses(0,0) or ConditionsResponses(0,0)
'if any one is true, there could be lost data.
for x = 0 to 2
if ConditionsResponses(x,0)= true then
msgStr = msgStr & ConditionsResponses(x,1)
end if
next x
If couldLoseData = True Then
msgStr = "You will lose data in the following areas as the relevant checkboxes are unticked." & vbcrlf & msgStr & vbcrlf
msgStr = msgStr & "Do you wish to continue?"
response = msgbox(msgstr, vbYesNo)
if response = vbno then
Cancel = True
End If
end if