Lazarus Pascal Requires Chilkat v11.7.0+

Embed a QR Code in HTML as a Data URI

See more QR Code Examples

Demonstrates putting a QR code directly into an HTML page or HTML email with no separate image file. The base64 PNG returned by QrCode becomes the src of an img tag as a data URI, which is the MIME type from outputs[0].mimeType followed by the base64 from outputs[0].base64. 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;
  json: TJsonObject;
  fmt: TFormats;
  jsonOut: TJsonObject;
  sbHtml: TStringBuilder;

begin
  success := False;

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

  json := TJsonObject.Create;
  json.UpdateString('payload.text','https://www.chilkatsoft.com/');
  json.UpdateInt('render.moduleSize',5);

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

  //  A data URI has the form  data:<MIME type>;base64,<base64 data>
  sbHtml := TStringBuilder.Create;
  sbHtml.Append('<html><body><p>Scan to visit chilkatsoft.com</p><img alt="QR code" width="');
  sbHtml.AppendInt(jsonOut.IntOf('outputs[0].width'));
  sbHtml.Append('" height="');
  sbHtml.AppendInt(jsonOut.IntOf('outputs[0].height'));
  sbHtml.Append('" src="data:');
  sbHtml.Append(jsonOut.StringOf('outputs[0].mimeType'));
  sbHtml.Append(';base64,');
  sbHtml.Append(jsonOut.StringOf('outputs[0].base64'));
  sbHtml.Append('"></body></html>');

  success := sbHtml.WriteFile('qa_output/qr_page.html','utf-8',False);
  if (success = False) then
    begin
      WriteLn(sbHtml.LastErrorText);
      Exit;
    end;

  WriteLn('image: ' + jsonOut.IntOf('outputs[0].width') + ' x ' + jsonOut.IntOf('outputs[0].height') + ' pixels');
  WriteLn('HTML length: ' + sbHtml.Length);

  //  The page, as a browser shows it:

  //  

  //  Sample output:

  //  image: 185 x 185 pixels
  //  HTML length: 1211


  json.Free;
  fmt.Free;
  jsonOut.Free;
  sbHtml.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.