At the framework level, I have a method which is calling an Overridable method such as:

        Private Function DataEntry() As Boolean

...

            ' Initialization code with row
            If Not InitializeWithRow() Then
                Return False
            End If

...

            Return True
        End Function

        Public Overridable Function InitializeWithRow() As Boolean
            Return True
        End Function

This is the main class. When the main class calls the Overridable method InitializeWithRow(), it has no way of knowing if the client application, which inherits from this class, has defined it or not. When the client application has defined it, it means a piece of code related to that method is present in the sub class such as:

    Public Overrides Function InitializeWithRow() As Boolean

        ' If the status is Voided or Closed
        If oProcess.oApp.Inlist(oRow("NoStatus"), 7, 8) Then
            AddDate("ContactDate", , False)
        Else
            AddDate("ContactDate", , False, True)
        End If

        Return True
    End Function

When this is the case, I would like the framework main class to validate for something before allowing the class to call the overrides method. But, I guess this is not possible.

Any comment?