Pascal (Lazarus/Delphi)

MercadoLibre Refresh OAuth2 Access Token

See more MercadoLibre Examples

Demonstrates how to refresh a MercadoLibre OAuth2 access token. The refresh does not require user interaction via a web browser. If an access token expires (typically with a 401 response code), a new access token can be automatically obtained by using the code in this example. 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.OAuth2,
  Chilkat.StringBuilder,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  jsonToken: TJsonObject;
  oauth2: TOAuth2;
  sbJson: TStringBuilder;

begin
  success := False;

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

  //  It is assumed we previously obtained an OAuth2 access token.
  //  This example loads the JSON access token file 
  //  saved by this example: Get MercadoLibre OAuth2 Access Token

  jsonToken := TJsonObject.Create;
  success := jsonToken.LoadFile('qa_data/tokens/mercadolibre.json');
  if (success <> True) then
    begin
      WriteLn('Failed to load mercadolibre.json');
      Exit;
    end;

  //  The access token JSON looks like this:

  //  {
  //    "access_token": "APP_USR-8133606632685744-060115-93e1fd8b5e767c51c238df347bd0b288-577628017",
  //    "token_type": "bearer",
  //    "expires_in": 21600,
  //    "scope": "offline_access read write",
  //    "user_id": 577625107,
  //    "refresh_token": "TG-5ad522a286f1200006ac4ed1-577625007"
  //  }

  oauth2 := TOAuth2.Create;

  oauth2.TokenEndpoint := 'https://api.mercadolibre.com/oauth/token';

  //  Replace these with actual values.
  oauth2.ClientId := 'MY_MERCADOLIBRE_APP_ID';
  oauth2.ClientSecret := 'MY_MERCADOLIBRE_APP_SECRET';

  //  Get the "refresh_token"
  oauth2.RefreshToken := jsonToken.StringOf('refresh_token');

  //  Send the HTTP POST to refresh the access token..
  success := oauth2.RefreshAccessToken();
  if (success <> True) then
    begin
      WriteLn(oauth2.LastErrorText);
      Exit;
    end;

  WriteLn('New access token: ' + oauth2.AccessToken);
  WriteLn('New refresh token: ' + oauth2.RefreshToken);

  //  Update the JSON with the new tokens.
  jsonToken.UpdateString('access_token',oauth2.AccessToken);
  jsonToken.UpdateString('refresh_token',oauth2.RefreshToken);

  //  Save the new JSON access token response to a file.
  sbJson := TStringBuilder.Create;
  jsonToken.EmitCompact := False;
  jsonToken.EmitSb(sbJson);
  sbJson.WriteFile('qa_data/tokens/mercadolibre.json','utf-8',False);

  WriteLn('OAuth2 authorization granted!');
  WriteLn('New Access Token = ' + oauth2.AccessToken);


  jsonToken.Free;
  oauth2.Free;
  sbJson.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.