(PureBasic) Google Drive Refresh Access Token

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

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkFileAccess.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkOAuth2.pb"

Procedure ChilkatExample()

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

    success.i = 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"
    ; }

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    tokenFilePath.s = "qa_data/tokens/googleDrive.json"
    CkJsonObject::ckLoadFile(json,tokenFilePath)

    oauth2.i = CkOAuth2::ckCreate()
    If oauth2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkOAuth2::setCkAccessToken(oauth2, CkJsonObject::ckStringOf(json,"access_token"))
    CkOAuth2::setCkRefreshToken(oauth2, CkJsonObject::ckStringOf(json,"refresh_token"))

    CkOAuth2::setCkAuthorizationEndpoint(oauth2, "https://accounts.google.com/o/oauth2/v2/auth")
    CkOAuth2::setCkTokenEndpoint(oauth2, "https://www.googleapis.com/oauth2/v4/token")

    ;  Replace these with actual values.
    CkOAuth2::setCkClientId(oauth2, "GOOGLE-CLIENT-ID")
    CkOAuth2::setCkClientSecret(oauth2, "GOOGLE-CLIENT-SECRET")
    CkOAuth2::setCkScope(oauth2, "https://www.googleapis.com/auth/drive")

    ; Use OAuth2 to refresh the access token.
    success = CkOAuth2::ckRefreshAccessToken(oauth2)
    If success <> 1
        Debug CkOAuth2::ckLastErrorText(oauth2)
        CkJsonObject::ckDispose(json)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    Debug CkOAuth2::ckAccessTokenResponse(oauth2)

    ; Save the new access token to our JSON file (so we can refresh it again when needed).
    CkJsonObject::ckUpdateString(json,"access_token",CkOAuth2::ckAccessToken(oauth2))

    fac.i = CkFileAccess::ckCreate()
    If fac.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkFileAccess::ckWriteEntireTextFile(fac,tokenFilePath,CkJsonObject::ckEmit(json),"utf-8",0)

    Debug "Access Token Refreshed!"


    CkJsonObject::ckDispose(json)
    CkOAuth2::ckDispose(oauth2)
    CkFileAccess::ckDispose(fac)


    ProcedureReturn
EndProcedure