Pascal (Lazarus/Delphi)

QR Code Generator via api.qrserver.com REST API

See more HTTP Examples

Demonstrates how to generate a QR code using the api.qrserver.com REST API service. 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.BinData,
  Chilkat.HttpResponse,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  http: THttp;
  queryParams: TJsonObject;
  resp: THttpResponse;
  bd: TBinData;

begin
  success := False;

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

  http := THttp.Create;

  //  Send the following GET request to get a binary response.
  //  The body of the binary response contains the image data for the QR code.
  //  https://api.qrserver.com/v1/create-qr-code/?data=[URL-encoded-text]&size=[pixels]x[pixels]

  queryParams := TJsonObject.Create;
  queryParams.UpdateString('data','Hello World');
  queryParams.UpdateString('size','100x100');

  //  Get a PNG file..
  //  Possible formats are:
  //  png
  //  gif
  //  jpeg
  //  jpg
  //  svg
  //  eps
  //  Case matters.  Use lowercase.
  queryParams.UpdateString('format','png');

  //  Send the GET request to an endpoint.
  //  Chilkat will add the url-encoded query params passed in the JSON.
  resp := THttpResponse.Create;
  success := http.HttpParams('GET','https://api.qrserver.com/v1/create-qr-code/',queryParams,resp);
  if (success = False) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  //  Did it succeed?
  if (resp.StatusCode <> 200) then
    begin
      //  The response body, if anything, would not be the image data, but would likely be the error text (or HTML, or whatever...)
      WriteLn(resp.BodyStr);
      WriteLn('Response status = ' + resp.StatusCode);
      WriteLn('Failed.');
      Exit;
    end;

  //  Success if we get here..
  //  Save the binary body as the PNG file, or you can get the bytes of the PNG..
  success := resp.SaveBodyBinary('c:/temp/qa_output/qr_code.png');

  //  Or get the bytes:
  bd := TBinData.Create;
  resp.GetBodyBd(bd);
  //  Use the bytes in bd...
  //  See the online reference documentation for the function to access the bytes directly.

  WriteLn('Success.');


  http.Free;
  queryParams.Free;
  resp.Free;
  bd.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.