Lazarus Pascal Requires Chilkat v11.7.0+

QR Code with Non-English Text (UTF-8 and ECI)

See more QR Code Examples

Demonstrates text outside ASCII. QrCode always stores text as UTF-8 bytes, which is what phones expect. A QR code can also say so explicitly with an ECI header: setting encoding.eci to 26 declares the bytes to be UTF-8, for readers that would otherwise assume another character set. The header costs a little space, and a few older readers do not understand it, so it is off by default. 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.StringBuilder,
  Chilkat.Formats,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  sbText: TStringBuilder;
  json: TJsonObject;
  fmt: TFormats;
  jsonOut: TJsonObject;

begin
  success := False;

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

  //  The text is "Gruesse aus Muenchen" written with u-umlaut and sharp s.  It is given here with
  //  JSON escapes only so that this source is plain ASCII.  Decode turns the escapes into characters.
  sbText := TStringBuilder.Create;
  sbText.Append('Gr\u00fc\u00dfe aus M\u00fcnchen');
  sbText.Decode('json','utf-8');

  json := TJsonObject.Create;
  json.UpdateSb('payload.text',sbText);
  json.UpdateString('output.path','qa_output/qr_utf8.png');
  json.UpdateBool('output.overwrite',True);
  json.UpdateString('output.return','none');

  fmt := TFormats.Create;
  jsonOut := TJsonObject.Create;
  success := fmt.QrCode('generate',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(fmt.LastErrorText);
      Exit;
    end;

  //  17 characters, three of which take two bytes in UTF-8.
  WriteLn('characters: ' + sbText.Length);
  WriteLn('bytes encoded: ' + jsonOut.IntOf('symbols[0].payloadBytes'));
  WriteLn('ECI header: ' + jsonOut.HasMember('symbols[0].selectedEncoding.eci'));

  //  Without an ECI header (qa_output/qr_utf8.png):

  //  

  //  The same text with an ECI header declaring UTF-8.
  json.UpdateInt('encoding.eci',26);
  json.UpdateString('output.path','qa_output/qr_utf8_eci.png');
  success := fmt.QrCode('generate',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(fmt.LastErrorText);
      Exit;
    end;
  WriteLn('with encoding.eci = 26, ECI header: ' + jsonOut.HasMember('symbols[0].selectedEncoding.eci') + ', value ' + jsonOut.IntOf('symbols[0].selectedEncoding.eci'));

  //  With the ECI header (qa_output/qr_utf8_eci.png).  Both scan as the same text:

  //  

  //  Sample output:

  //  characters: 17
  //  bytes encoded: 20
  //  ECI header: False
  //  with encoding.eci = 26, ECI header: True, value 26


  sbText.Free;
  json.Free;
  fmt.Free;
  jsonOut.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.