Lazarus Pascal

Get Access Token for Google Tasks using Service Account JSON Key

See more Google Tasks Examples

Demonstrates how to get an access token for the Google Tasks API using a Service Account JSON key. Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.FileAccess,
  Chilkat.AuthGoogle,
  Chilkat.Socket;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  fac: TFileAccess;
  jsonKey: string;
  gAuth: TAuthGoogle;
  tlsSock: TSocket;

begin
  success := False;

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

  //  First load the JSON key into a string.
  fac := TFileAccess.Create;
  jsonKey := fac.ReadEntireTextFile('qa_data/googleSvcAccountKeys/ChilkatCloud-48f7737c7505.json','utf-8');
  if (fac.LastMethodSuccess <> True) then
    begin
      WriteLn(fac.LastErrorText);
      Exit;
    end;

  //  A JSON private key should look like this:

  //  {
  //    "type": "service_account",
  //    "project_id": "chilkatcloud",
  //    "private_key_id": "48f7737c7505bb88eee6a20d09993e10605d466e",
  //    "private_key": "-----BEGIN PRIVATE KEY----- ... -----END PRIVATE KEY-----\n",
  //    "client_email": "pip-564@chilkatcloud.iam.gserviceaccount.com",
  //    "client_id": "109982228323456925225",
  //    "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  //    "token_uri": "https://oauth2.googleapis.com/token",
  //    "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  //    "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/pip-564%40chilkatcloud.iam.gserviceaccount.com"
  //  }

  gAuth := TAuthGoogle.Create;
  gAuth.JsonKey := jsonKey;

  //  Choose the scope for read/write access.
  gAuth.Scope := 'https://www.googleapis.com/auth/tasks';

  //  Request an access token that is valid for this many seconds.
  gAuth.ExpireNumSeconds := 3600;

  gAuth.SubEmailAddress := '';

  //  Connect to www.googleapis.com using TLS
  tlsSock := TSocket.Create;
  success := tlsSock.Connect('www.googleapis.com',443,True,5000);
  if (success <> True) then
    begin
      WriteLn(tlsSock.LastErrorText);
      Exit;
    end;

  //  Send the request to obtain the access token.
  success := gAuth.ObtainAccessToken(tlsSock);
  if (success <> True) then
    begin
      WriteLn(gAuth.LastErrorText);
      Exit;
    end;

  //  Examine the access token:
  WriteLn('Access Token: ' + gAuth.AccessToken);

  //  Save our access token to a file.
  success := fac.WriteEntireTextFile('qa_data/tokens/googleTasks.txt',gAuth.AccessToken,'utf-8',False);


  fac.Free;
  gAuth.Free;
  tlsSock.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.