DRYing up an initialization pattern

I maintain a VBA process that prints a large number of PDFs. It was awful when I inherited it and I've been making improvements over time, but I'm a bit stuck on this one. There are at least 4 functions with this exact same code used to check to see if the program has been initialized properly. They could all be called individually, or together depending on circumstances.

I do not want to initialize again if I don't have to. Hence the check in every subroutine, but I just can't figure out how to do it any differently. Thoughts? Is there a design pattern to deal with this kind of thing that I don't know of?

Please try to focus on the pattern and not the supporting intitializer. I know there are a few issues there and intend to deal with them soon. I included it in case it was relevant.

Main code:

Private rootDir As String
Private isInit As Boolean
Private mCycle As String

Public Function printPDF_VoidedNewItems()
    If Not isInit Then
        initialize
    End If
    If rootDir <> "" And mCycle <> "" Then
        If setPrinterToPDF() Then
            ' logic specific to printing this pdf
        End If
    End If
End Function

Public Function printPDF_ComsNotFed()
    If Not isInit Then
        initialize
    End If
    If rootDir <> "" And mCycle <> "" Then
        If setPrinterToPDF() Then
            ' logic specific to printing this pdf
        End If
    End If
End Function

Initializer:

```
Private Sub initialize()
rootDir = folderPicker() & "\"
mCycle = getCycleInput
isInit = True
End Sub

Private Function folderPicker() As String
'***
' returns directory path to be printed to
' does not allow multiple selections,
' so returning the first item in selected
' items is sufficient.
'
' returns empty string On Error or if the
' user cancels
'****
On Error GoTo ErrHandler

Dim folderChosen As Integer
Dim fd As Variant
Set fd = Application.F

Down with the underscore

I find the naming of printPdf_xxxx functions confusing, because if that code is/were in a class module they should be private, and the class would say Implements printPdf, where printPdf would be a class with VoidedNewItems and ComsNotFed members... or it could be that there's a private field called printPdf that's declared WithEvents and the functions are event handlers made public.

Avoid underscores in procedure & function (/method) names, the language has a meaning for identifiers with an underscore.

Initializing once

If you scratch that code and implement it in a class instead, and run initialisation in the... Class_Initialize method, which can be thought of as a parameterless constructor that runs when you create the object. Not too crazy about spawning a UI prompt in that handler though, but then the methods wouldn't have to worry about whether or not Initialize has executed.

StackExchange Code Review Q#55896, answer score: 6