(Visual Basic 6.0) Google Drive Refresh Access Token

Demonstrates how to automatically refresh the access token when it expires.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim success As Long
success = 1

' This example uses a previously obtained access token having permission for the 
' Google Drive scope.

' The access token (and refresh token) was previously saved to a JSON file with this format:
' See Get Google Drive OAuth2 Access Token

' {
'   "access_token": "ya29.Gls-BsdxTWuenChv ... yzVIrXikkLxu5T6dy4I6GjADFardoz4Lruw",
'   "expires_in": 3600,
'   "refresh_token": "1/tMBJ ... 27D-Hk6rpQYBA",
'   "scope": "https://www.googleapis.com/auth/drive",
'   "token_type": "Bearer"
' }

Dim json As New ChilkatJsonObject
Dim tokenFilePath As String
tokenFilePath = "qa_data/tokens/googleDrive.json"
success = json.LoadFile(tokenFilePath)

Dim oauth2 As New ChilkatOAuth2
oauth2.AccessToken = json.StringOf("access_token")
oauth2.RefreshToken = json.StringOf("refresh_token")

oauth2.AuthorizationEndpoint = "https://accounts.google.com/o/oauth2/v2/auth"
oauth2.TokenEndpoint = "https://www.googleapis.com/oauth2/v4/token"

'  Replace these with actual values.
oauth2.ClientId = "GOOGLE-CLIENT-ID"
oauth2.ClientSecret = "GOOGLE-CLIENT-SECRET"
oauth2.Scope = "https://www.googleapis.com/auth/drive"

' Use OAuth2 to refresh the access token.
success = oauth2.RefreshAccessToken()
If (success <> 1) Then
    Debug.Print oauth2.LastErrorText
    Exit Sub
End If

Debug.Print oauth2.AccessTokenResponse

' Save the new access token to our JSON file (so we can refresh it again when needed).
success = json.UpdateString("access_token",oauth2.AccessToken)

Dim fac As New CkFileAccess
success = fac.WriteEntireTextFile(tokenFilePath,json.Emit(),"utf-8",0)

Debug.Print "Access Token Refreshed!"