VBA Validation Module

Attribute VB_Name = "basValidation"

Option Explicit
'    Name:     basValidationFunctions

'    Purpose:  each function will perform a primitive datatype
'              validation and return a boolean value

'    Note:     The variant data type is used for all parameters as
'              the form sets the value property for a text/combo box
'              to NULL if the user does not supply data.  Variant is
'              the only data type that stores the NULL value.
'
'              BCS 240/340 Validation Code Re - Instructor: Shane Bell


Public Function RequiredInteger(ByVal varNumber As Variant) As Boolean

'    Validate a required integer field

'    Criteria: cannot be null, must be a whole number

'    establish error handler

'     On Error GoTo RequiredInteger_Err

'    Assume invalid data

     RequiredInteger = False

'    Check criteria

     If IsNumeric(varNumber) Then
          If CDbl(varNumber) = CLng(varNumber) Then
               RequiredInteger = True
          End If
     End If

'RequiredInteger_Exit:
'
'     Exit Function
'
'RequiredInteger_Err:
'
'     Call ErrorHandler("RequiredInteger", "basValidationFunctions")
'     End

End Function

Public Function RequiredNumber(ByVal varNumber As Variant) As Boolean

'    Validate a required numeric field

'    Criteria: cannot be null, must be a number

'    establish error handler

'     On Error GoTo RequiredNumber_Err

'    Assume invalid data

     RequiredNumber = False

'    Check criteria

     If IsNumeric(varNumber) Then
          RequiredNumber = True
     End If

'RequiredNumber_Exit:
'
'     Exit Function
'
'RequiredNumber_Err:
'
'     Call ErrorHandler("RequiredNumber", "basValidationFunctions")
'     End

End Function

Public Function RequiredDate(ByVal varDate As Variant) As Boolean

'    Validate a required date field

'    Criteria: cannot be null, must be a date

'    establish error handler

'     On Error GoTo RequiredDate_Err

'    Assume invalid data

     RequiredDate = False

'    Check criteria

     If Not IsNumeric(varDate) Then
          If IsDate(varDate) Then
               RequiredDate = True
          End If
     End If
'
'RequiredDate_Exit:
'
'     Exit Function
'
'RequiredDate_Err:
'
'     Call ErrorHandler("RequiredDate", "basValidationFunctions")
'     End

End Function

Public Function RequiredText(ByVal varText As Variant) As Boolean

'    Validate a required text field

'    Criteria: cannot be null, cannot be a date, cannot be a number

'    establish error handler

'     On Error GoTo RequiredText_Err

'    Assume invalid data

     RequiredText = False

'    Check criteria

     If Not IsNull(varText) Then
          If Not IsDate(varText) Then
               If Not IsNumeric(varText) Then
                    RequiredText = True
               End If
          End If
     End If

'RequiredText_Exit:
'
'     Exit Function
'
'RequiredText_Err:
'
'     Call ErrHandler("RequiredText", "basValidationFunctions")
'     End

End Function

Public Function RequiredAlphaNumeric(ByVal varAlphaNumeric As Variant) As Boolean

'    Validate a required text field

'    Criteria: cannot be null, cannot be a date

'    establish error handler

'     On Error GoTo RequiredAlphaNumeric_Err

'    Assume invalid data

     RequiredAlphaNumeric = False

'    Check criteria

     If Not IsNull(varAlphaNumeric) Then
          If Not IsDate(varAlphaNumeric) Then
               RequiredAlphaNumeric = True
          End If
     End If

'RequiredAlphaNumeric_Exit:
'
'     Exit Function
'
'RequiredAlphaNumeric_Err:
'
'     Call ErrorHandler("RequiredAlphNumeric", "basValidationFunctions")
'     End

End Function

Public Function NotRequiredInteger(ByVal varNumber As Variant) As Boolean

'    Validate a not required integer field

'    Criteria: must be a whole number or null

'    establish error handler

'     On Error GoTo NotRequiredInteger_Err

'    Assume invalid data

     NotRequiredInteger = False

'    Check criteria

     If IsNull(varNumber) Then
          NotRequiredInteger = True
     Else
          If IsNumeric(varNumber) Then
               If CDbl(varNumber) = CLng(varNumber) Then
                    NotRequiredInteger = True
               End If
          End If
     End If

'NotRequiredInteger_Exit:
'
'     Exit Function
'
'NotRequiredInteger_Err:
'
'     Call ErrorHandler("NotRequiredInteger", "basValidationFunctions")
'     End

End Function

Public Function NotRequiredNumber(ByVal varNumber As Variant) As Boolean


'    Validate a not required numeric field

'    Criteria: must be a number or null

'    establish error handler

'     On Error GoTo NotRequiredNumber_Err

'    Assume invalid data

     NotRequiredNumber = False

'    Check criteria

     If IsNull(varNumber) Then
          NotRequiredNumber = True
     Else
          If IsNumeric(varNumber) Then
               NotRequiredNumber = True
          End If
     End If
'
'NotRequiredNumber_Exit:
'
'     Exit Function
'
'NotRequiredNumber_Err:
'
'     Call ErrorHandler("NotRequiredNumber", "basValidationFunctions")
'     End

End Function

Public Function NotRequiredDate(ByVal varDate As Variant) As Boolean


'    Validate a not required date field

'    Criteria: must be a date or null

'    establish error handler

'     On Error GoTo NotRequiredDate_Err

'    Assume invalid data

     NotRequiredDate = False

'    Check criteria

     If IsNull(varDate) Then
          NotRequiredDate = True
     Else
          If IsDate(varDate) Then
               NotRequiredDate = True
          End If
     End If

'NotRequiredDate_Exit:
'
'     Exit Function
'
'NotRequiredDate_Err:
'
'     Call ErrorHandler("NotRequiredDate", "basValidationFunctions")
'     End

End Function

Public Function NotRequiredText(ByVal varText As Variant) As Boolean


'    Validate a not required text field

'    Criteria: can be null or any other value except a date or a number

'    establish error handler

'     On Error GoTo NotRequiredText_Err

'    Assume invalid data

     NotRequiredText = False

'    Check criteria

     If IsNull(varText) Then
          NotRequiredText = True
     Else
          If Not IsDate(varText) Then
               If Not IsNumeric(varText) Then
                    NotRequiredText = True
               End If
          End If
     End If

'NotRequiredText_Exit:
'
'     Exit Function
'
'NotRequiredText_Err:
'
'     Call ErrorHandler("NotRequiredText", "basValidationFunctions")
'     End

End Function

Public Function NotRequiredAlphaNumeric(ByVal varAlphaNumeric As Variant) As Boolean


'    Validate a required text field

'    Criteria: cannot be a date

'    establish error handler

     On Error GoTo NotRequiredAlphaNumeric_Err

'    Assume invalid data

     NotRequiredAlphaNumeric = False

'    Check criteria

     If IsNull(varAlphaNumeric) Then
          NotRequiredAlphaNumeric = True
     Else
          If Not IsDate(varAlphaNumeric) Then
               NotRequiredAlphaNumeric = True
          End If
     End If

'NotRequiredAlphaNumeric_Exit:
'
'     Exit Function
'
'NotRequiredAlphaNumeric_Err:
'
'     Call ErrorHandler("NotRequiredAlphaNumeric", "basValidationFunctions")
'     End

End Function