(VB.NET UWP/WinRT) Google Drive Refresh Access Token

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

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

Dim success As Boolean = True

' 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 Chilkat.JsonObject
Dim tokenFilePath As String = "qa_data/tokens/googleDrive.json"
json.LoadFile(tokenFilePath)

Dim oauth2 As New Chilkat.OAuth2
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 = Await oauth2.RefreshAccessTokenAsync()
If (success <> True) Then
    Debug.WriteLine(oauth2.LastErrorText)
    Exit Sub
End If


Debug.WriteLine(oauth2.AccessTokenResponse)

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

Dim fac As New Chilkat.FileAccess
fac.WriteEntireTextFile(tokenFilePath,json.Emit(),"utf-8",False)

Debug.WriteLine("Access Token Refreshed!")