Pascal (Lazarus/Delphi)

Calendar: Refresh Expired OAuth2 Access Token

See more Microsoft Calendar Examples

Refreshes an expired OAuth2 access token. 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.Http,
  Chilkat.HttpRequest,
  Chilkat.HttpResponse,
  Chilkat.JsonObject,
  Chilkat.FileAccess;

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

procedure RunDemo;
var
  success: Boolean;
  json: TJsonObject;
  req: THttpRequest;
  http: THttp;
  resp: THttpResponse;
  fac: TFileAccess;

begin
  success := False;

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

  json := TJsonObject.Create;
  success := json.LoadFile('qa_data/tokens/msGraphCalendar.json');
  if (success <> True) then
    begin
      Exit;
    end;

  req := THttpRequest.Create;
  req.AddParam('grant_type','refresh_token');
  req.AddParam('redirect_uri','http://localhost:3017/');
  req.AddParam('client_id','MICROSOFT-GRAPH-CLIENT-ID');
  req.AddParam('client_secret','MICROSOFT-GRAPH-CLIENT-SECRET');
  req.AddParam('refresh_token',json.StringOf('refresh_token'));
  req.AddParam('scope','openid profile offline_access user.readwrite calendars.readwrite files.readwrite');

  http := THttp.Create;

  req.HttpVerb := 'POST';
  req.ContentType := 'application/x-www-form-urlencoded';

  resp := THttpResponse.Create;
  success := http.HttpReq('https://login.microsoftonline.com/common/oauth2/v2.0/token',req,resp);
  if (success = False) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  //  Load the JSON response.
  json.Load(resp.BodyStr);
  json.EmitCompact := False;

  //  Show the JSON response.
  WriteLn(json.Emit());

  WriteLn('Response status code: ' + resp.StatusCode);

  //  If the response status code is not 200, then it's an error.
  if (resp.StatusCode <> 200) then
    begin
      Exit;
    end;

  //  Save the refreshed access token JSON to a file for future requests.
  fac := TFileAccess.Create;
  fac.WriteEntireTextFile('qa_data/tokens/msGraphCalendar.json',json.Emit(),'utf-8',False);

  WriteLn('Success.');


  json.Free;
  req.Free;
  http.Free;
  resp.Free;
  fac.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.