Delphi DLL

Google Drive Refresh Access Token

See more Google Drive Examples

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, FileAccess, OAuth2, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
json: HCkJsonObject;
tokenFilePath: PWideChar;
oauth2: HCkOAuth2;
fac: HCkFileAccess;

begin
success := False;

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

success := 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"
// }

json := CkJsonObject_Create();
tokenFilePath := 'qa_data/tokens/googleDrive.json';
CkJsonObject_LoadFile(json,tokenFilePath);

oauth2 := CkOAuth2_Create();
CkOAuth2_putAccessToken(oauth2,CkJsonObject__stringOf(json,'access_token'));
CkOAuth2_putRefreshToken(oauth2,CkJsonObject__stringOf(json,'refresh_token'));

CkOAuth2_putAuthorizationEndpoint(oauth2,'https://accounts.google.com/o/oauth2/v2/auth');
CkOAuth2_putTokenEndpoint(oauth2,'https://www.googleapis.com/oauth2/v4/token');

//  Replace these with actual values.
CkOAuth2_putClientId(oauth2,'GOOGLE-CLIENT-ID');
CkOAuth2_putClientSecret(oauth2,'GOOGLE-CLIENT-SECRET');
CkOAuth2_putScope(oauth2,'https://www.googleapis.com/auth/drive');

// Use OAuth2 to refresh the access token.
success := CkOAuth2_RefreshAccessToken(oauth2);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkOAuth2__lastErrorText(oauth2));
    Exit;
  end;

Memo1.Lines.Add(CkOAuth2__accessTokenResponse(oauth2));

// Save the new access token to our JSON file (so we can refresh it again when needed).
CkJsonObject_UpdateString(json,'access_token',CkOAuth2__accessToken(oauth2));

fac := CkFileAccess_Create();
CkFileAccess_WriteEntireTextFile(fac,tokenFilePath,CkJsonObject__emit(json),'utf-8',False);

Memo1.Lines.Add('Access Token Refreshed!');

CkJsonObject_Dispose(json);
CkOAuth2_Dispose(oauth2);
CkFileAccess_Dispose(fac);

end;