Pascal (Lazarus/Delphi)

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. Pascal (Lazarus/Delphi)

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.