Binaryworld - CUDL - A class to create UDL files ... [ VB -> ADO ]

' A class that creates UDL files for use as ADO Data Sources.

' Universal Data link files are handy for select data sources but there
' are lack of a way to create/edit this files. The little program i
' attached teaches how to read/write a UDL file.

' IMPORTANT: requires that you add a reference to the following library:
'  Microsoft OLE DB Service Component 1.0 Type Llibrary
' in the oledb32.dll file

' Usage example:
'   ' To create a new UDL file.
'   Dim udl As New cUdl
'   If udl.CreateUDL Then udl.SaveToFile "c:\yourfile.udl"

'   ' To open and edit an existing UDL file
'   Dim udl As New cUdl
'   udl.LoadFromFile "c:\yourfile.udl"
'   udl.OpenUDL

Private Const CON_UDL_LINE1 = "[oledb]"
Private Const CON_UDL_LINE2 = "; Everything after this line is an OLE DB " _
  & "initstring"
Private mvarADOConnectString As String

Public Property Let ADOConnectString(ByVal vData As String)
  mvarADOConnectString = vData
End Property

Public Property Get ADOConnectString() As String
  ADOConnectString = mvarADOConnectString
End Property

Public Function CreateUDL() As Boolean
  On Error GoTo Err_CreateUDL
  Dim pDataLink As New DataLinks, pConn As Connection

  Set pConn = pDataLink.PromptNew
  pConn.Open
  mvarADOConnectString = pConn.ConnectionString
  pConn.Close

  CreateUDL = True
  Exit Function
Err_CreateUDL:
  CreateUDL = False
End Function

Public Function OpenUDL(Optional ByVal strConnectString As String) As Boolean
  On Error GoTo Err_OpenUDL
  Dim pDataLink As New DataLinks, pConn As New Connection
  If mvarADOConnectString = vbNullString Then
    OpenUDL = CreateUDL
    Exit Function
  Else
    pConn.ConnectionString = mvarADOConnectString
    If pDataLink.PromptEdit(pConn) Then
      pConn.Open
      mvarADOConnectString = pConn.ConnectionString
      pConn.Close
    End If
  End If
  OpenUDL = True
  Exit Function
Err_OpenUDL:
  OpenUDL = False
End Function

Public Sub SaveToFile(ByVal strUDLFile As String)
  Dim strBuf As String, intFileNum As Integer

  strBuf = CON_UDL_LINE1 & vbCrLf & CON_UDL_LINE2 & vbCrLf & _
    mvarADOConnectString
  strBuf = StrConv(strBuf, vbUnicode)
  intFileNum = FreeFile
  If Dir(strUDLFile) <> vbNullString Then Kill strUDLFile
  Open strUDLFile For Binary As #intFileNum
  Put #intFileNum, , strBuf
  Close #intFileNum
End Sub

Public Function LoadFromFile(ByVal strUDLFile As String) As Boolean
  Dim intFileNum As Integer, strBuf As String, i As Integer
  intFileNum = FreeFile
  Open strUDLFile For Binary As #intFileNum
  strBuf = Input(LOF(intFileNum), #intFileNum)
  Close #intFileNum
  strBuf = StrConv(strBuf, vbFromUnicode)
  i = InStr(strBuf, "Provider=")
  If i > 0 Then
    mvarADOConnectString = Mid(strBuf, i)
    LoadFromFile = True
  Else
    LoadFromFile = False
  End If
End Function