(Visual FoxPro) Google People API Refresh Access Token

Demonstrates how to refresh a Google Access Token for the Google People API.

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

LOCAL loJsonToken
LOCAL lnSuccess
LOCAL loOauth2
LOCAL loSbJson

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

* It is assumed we previously obtained an OAuth2 access token.
* This example loads the JSON access token file 
* saved by this example: Get Google People API OAuth2 Access Token

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJsonToken = CreateObject('Chilkat.JsonObject')
lnSuccess = loJsonToken.LoadFile("qa_data/tokens/googlePeople.json")
IF (lnSuccess <> 1) THEN
    ? "Failed to load googlePeople.json"
    RELEASE loJsonToken
    CANCEL
ENDIF

* The access token JSON looks like this:

* {
*   "access_token": "ya29.a0AfH6S ... LAZYFUkf0",
*   "expires_in": 3599,
*   "refresh_token": "1//0fL_Ov ... ee0",
*   "scope": "https://www.googleapis.com/auth/contacts",
*   "token_type": "Bearer"
* }

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.OAuth2')
loOauth2 = CreateObject('Chilkat.OAuth2')

loOauth2.TokenEndpoint = "https://www.googleapis.com/oauth2/v4/token"

* Replace these with actual values.
loOauth2.ClientId = "GOOGLE-CLIENT-ID"
loOauth2.ClientSecret = "GOOGLE-CLIENT-SECRET"

* Get the "refresh_token"
loOauth2.RefreshToken = loJsonToken.StringOf("refresh_token")

* Send the HTTP POST to refresh the access token..
lnSuccess = loOauth2.RefreshAccessToken()
IF (lnSuccess <> 1) THEN
    ? loOauth2.LastErrorText
    RELEASE loJsonToken
    RELEASE loOauth2
    CANCEL
ENDIF

* The response contains a new access token, but we must keep
* our existing refresh token for when we need to refresh again in the future.
loJsonToken.UpdateString("access_token",loOauth2.AccessToken)

* Save the new JSON access token response to a file.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbJson = CreateObject('Chilkat.StringBuilder')
loJsonToken.EmitCompact = 0
loJsonToken.EmitSb(loSbJson)
loSbJson.WriteFile("qa_data/tokens/googlePeople.json","utf-8",0)

? "OAuth2 authorization granted!"
? "New Access Token = " + loOauth2.AccessToken

RELEASE loJsonToken
RELEASE loOauth2
RELEASE loSbJson