Pascal (Lazarus/Delphi)

PDF Signatures with Built-in SVG Graphics

See more PDF Signatures Examples

This example demonstrates the built-in SVG graphics that can be applied to the appearance when signing a PDF.

Note: This example requires Chilkat v9.5.0.85 or greater.

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.Pdf,
  Chilkat.Cert,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  pdf: TPdf;
  json: TJsonObject;
  cert: TCert;

begin
  success := False;

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

  pdf := TPdf.Create;

  //  Load a PDF to be signed.
  //  The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
  success := pdf.LoadFile('qa_data/pdf/hello.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  //  Options for signing are specified in JSON.
  json := TJsonObject.Create;

  //  In most cases, the signingCertificateV2 and signingTime attributes are required.
  json.UpdateInt('signingCertificateV2',1);
  json.UpdateInt('signingTime',1);

  //  Specify the location/position, scale, and content of the signature's appearance.
  json.UpdateInt('page',1);
  json.UpdateString('appearance.y','top');
  json.UpdateString('appearance.x','left');
  json.UpdateString('appearance.fontScale','10.0');
  json.UpdateString('appearance.text[0]','Digitally signed by: cert_cn');
  json.UpdateString('appearance.text[1]','current_dt');
  json.UpdateString('appearance.text[2]','The crazy brown fox jumps over the lazy dog.');

  //  In addition to the above, this example adds a built-in SVG graphic to the appearance.
  //  The built-in SVG graphic is specified by a name, such as "green-check-grey-circle".
  //  The full list of graphic names and images are shown below.
  json.UpdateString('appearance.image','green-check-grey-circle');

  //  The graphic can be placed "left", "center", or "right".
  //  If "center", then the graphic is displayed behind the text.
  json.UpdateString('appearance.imagePlacement','left');

  //  The graphic's opacity can range from 1 to 100.
  //  Centered graphics look best with less opacity (50 or less).
  //  In this example, we'll keep the opacity at 100.
  json.UpdateString('appearance.imageOpacity','100');

  //  Here's an example of the signature's appearance if we centered the SVG graphic with an opacity of 40%
  //  (image:https://example-code.com/images/centered_svg.jpg/endImage)

  //  Load the signing certificate. (Use your own certificate.)
  cert := TCert.Create;
  success := cert.LoadPfxFile('qa_data/pfx/myPdfSigningCert.pfx','secret');
  if (success = False) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  Tell the pdf object to use the certificate for signing.
  success := pdf.SetSigningCert(cert);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  success := pdf.SignPdf(json,'qa_output/hello_signed.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  WriteLn('The PDF has been successfully cryptographically signed.');

  //  The appearance of the signature appears in Adobe Acrobat as shown here:

  //  (image:https://example-code.com/images/pdf_signature_green_check_grey_circle.jpg/endImage)

  //  The SVG icon graphics are embedded within the Chilkat library, 
  //  and were graciously provided by uxwing - Free SVG Icons 
  //  
  //  The uxwing licensing terms are reproduced here and can be verified at uxwing licensing

  //  Icons from uxwing.com are free (see https://uxwing.com/license/)
  //  	- All icons on UXWing free to download, and use personal, commercial projects.
  //  	- Attribution and Credit is NOT required, however, any credit will be much appreciated.
  //  	- There is no limit to the number of times you can use.
  //  	- You may modify the resources according to your requirements.

  //  The set of SVG names and the corresponding graphics are shown below.
  //  
  //  For example, if we specify "green-check-green-circle"
  json.UpdateString('appearance.image','green-check-green-circle');
  //  We get:
  //  (image:https://example-code.com/images/green-check-green-circle.jpg/endImage)

  //  "application-approved"
  //  (image:https://example-code.com/images/application-approved.jpg/endImage)

  //  "application-rejected"
  //  (image:https://example-code.com/images/application-rejected.jpg/endImage)

  //  "document-accepted"
  //  (image:https://example-code.com/images/document-accepted.jpg/endImage)

  //  "approved"
  //  (image:https://example-code.com/images/approved.jpg/endImage)

  //  "blue-check-mark"
  //  (image:https://example-code.com/images/blue-check-mark.jpg/endImage)

  //  "green-check-mark"
  //  (image:https://example-code.com/images/green-check-mark.jpg/endImage)

  //  "green-check-grey-circle"
  //  (image:https://example-code.com/images/green-check-grey-circle.jpg/endImage)

  //  "red-x-red-circle"
  //  (image:https://example-code.com/images/red-x-red-circle.jpg/endImage)

  //  "rejected"
  //  (image:https://example-code.com/images/rejected.jpg/endImage)

  //  "result-failure"
  //  (image:https://example-code.com/images/result-failure.jpg/endImage)

  //  "result-pass"
  //  (image:https://example-code.com/images/result-pass.jpg/endImage)

  //  "signature"
  //  (image:https://example-code.com/images/signature.jpg/endImage)

  //  "document-check"
  //  (image:https://example-code.com/images/document-check.jpg/endImage)

  //  "document-x"
  //  (image:https://example-code.com/images/document-x.jpg/endImage)

  //  "red-x-grey-circle"
  //  (image:https://example-code.com/images/red-x-grey-circle.jpg/endImage)


  pdf.Free;
  json.Free;
  cert.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.