'====================================================================================================================
'Public Function CheckOnlineUpgrade(DBCon as ADODB.Connection) as Boolean
'
' If this returns true immediately "End" current App.
'
' DBCon must evaluate to an active and open connection to a data source with read access to the following table
'
' CREATE TABLE App_Versions (
'     app_title varchar(255) not null,   -- The title of the VB application as determined by App.Title
'     major int not null,                -- The major version as determined by App.Major (requires upgrade)
'     minor int not null,                -- The minor version as determined by App.Minor (optional upgrade)
'     revision int not null,             -- The revision number as determined by App.Revision (silent upgrade)
'     upgrade_url varchar(255) not null) -- The full URL to a executable upgrade routine
'
'--------------------------------------------------------------------------------------------------------------------
' System Requirements:
'       Microsoft Visual Basic Runtime 6.0 or higher
'       Microsoft Internet Explorer 4.0 or higher
'       Microsoft Data Access Components 2.0 or higher
'       Sage Analytic Upgrade Agent 1.0 or higher
'
' Make sure to reference "Microsoft ActiveX Data Objects 2.0 Library" or higher in your Visual Basic project
'
' Written by: Sage Analytic (http://www.sageanalytic.com)
'             02/23/2001
'
'====================================================================================================================

Declare Function GetCurrentProcessId Lib "kernel32" () As Long

Public Function CheckOnlineUpgrade(DBCon As ADODB.Connection) As Boolean

Dim UpgradeAvailable As Boolean
Dim UpgradeRequired As Boolean
Dim AppRS As New ADODB.Recordset
Dim LocalFilename As String
Dim RemoteFilename As String
UpgradeAvailable = False
UpgradeRequired = False


AppRS.Open "SELECT major, minor, revision, upgrade_url FROM App_Versions WHERE app_title = '" + App.Title + "'", DBCon

If Not AppRS.EOF Then
  RemoteFilename = AppRS("upgrade_url")
  LocalFilename = Trim(App.Path) + "\" + Mid(RemoteFilename, InStrRev(RemoteFilename, "/") + 1)

  If AppRS("major").Value > App.Major Then
    ' If Major has changed then an upgrade is mandatory
    UpgradeAvailable = True
    UpgradeRequired = True
  ElseIf AppRS("major").Value = App.Major And AppRS("minor").Value > App.Minor Then
    ' If only Minor has changed then an upgrade is optional
    UpgradeAvailable = True
    UpgradeRequired = False
  ElseIf AppRS("major").Value = App.Major And AppRS("minor").Value = App.Minor And AppRS("revision").Value > App.Revision Then
    ' If only Revision has changed then an upgrade is optional and do not even prompt the user
    UpgradeAvailable = False
    UpgradeRequired = False
  End If
End If

If UpgradeRequired Then
  CheckOnlineUpgrade = True
  If MsgBox("An mandatory upgrade for this application is available. " + vbCrLf + _
      "The new version will be downloaded and installed automatically for you. " + vbCrLf + _
      "You will not be able to run this application until the upgrade has been performed.", _
      vbOKCancel + vbExclamation, "Application Version Check") = vbCancel Then
  UpgradeRequired = False
  End If
ElseIf UpgradeAvailable Then
  If MsgBox("An upgrade for this application is available. " + vbCrLf + vbCrLf + _
      "Do you wish to download and install the upgrade at this time?", vbYesNo + vbExclamation, _
      "Application Version Check") = vbYes Then
    CheckOnlineUpgrade = True
    UpgradeRequired = True
  End If
End If

If UpgradeRequired Then
  On Error Resume Next
  If Shell("""" + Trim(App.Path) + "\UpgradeAgent.exe"" /R " + RemoteFilename + _
      " /L """ + LocalFilename + """" + _
      " /A """ + App.Title + """" + _
      " /E """ + Trim(App.Path) + "\" + Trim(App.EXEName) + ".exe""" + _
      " /P " + CStr(GetCurrentProcessId()) + " /D", vbNormalFocus) = 0 Then
    MsgBox "ERROR: The upgrade agent could not be started.", vbCritical, "Application Version Check"
  End If
End If

End Function

'==============================================================================================