Pascal (Lazarus/Delphi)

Refresh a Square OAuth2 Access Token

See more Square Examples

Refreshes a Square OAuth2 access token. When an access token expires, HTTPS requests will receive a 401 status response indicating failure. When this happens, your application can run this code to refresh the access token, and then retry the request using the new access token. Refreshing an access token does not need user interaction (i.e. does not need to display a browser to have the user interactive authorize access). 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 Square OAuth2 Access Token

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

  //  The access token JSON looks like this:

  //  {
  //    "access_token": "EAAAE...depV",
  //    "token_type": "bearer",
  //    "expires_at": "2020-09-04T23:30:18Z",
  //    "merchant_id": "MLQA83866KSR5",
  //    "refresh_token": "EQAAEE...jeVfD6MV"
  //  }

  oauth2 := TOAuth2.Create;

  oauth2.TokenEndpoint := 'https://connect.squareupsandbox.com/oauth2/token';

  //  Replace these with actual values.
  oauth2.ClientId := 'APPLICATION_ID';
  oauth2.ClientSecret := 'APPLICATION_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;

  jsonToken.UpdateString('access_token',oauth2.AccessToken);

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

  WriteLn('OAuth2 token refreshed!');
  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.