Lazarus Pascal Requires Chilkat v11.7.0+

Replace the Value After a Label in a PDF (Re-issue an Invoice)

See more PDF Text Replacement Examples

Demonstrates replacing the values that follow labels such as "Invoice Number:" on a PDF that has no placeholders -- an ordinary invoice. Each entry of the "labels" array names a label as it appears on the page and the new value; the value replaces the rest of the label's line. Label matching ignores case, extra spaces and a trailing colon. The replaced text is read back with ExtractText to confirm it. 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.Pdf,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  pdf: TPdf;
  json: TJsonObject;
  jsonOut: TJsonObject;
  i: Integer;
  count_i: Integer;
  jsonRead: TJsonObject;
  jsonText: TJsonObject;

begin
  success := False;

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

  //  The PDF used in this example is available at invoice_labels.pdf

  pdf := TPdf.Create;
  success := pdf.LoadFile('qa_data/pdf/invoice_labels.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  //  The invoice has lines such as "Invoice Number:   INV-2026-0412" and "Total Due:  $1,234.53".
  //  Each label's new value replaces whatever follows the label on its line.
  json := TJsonObject.Create;
  json.UpdateString('labels[0].label','Invoice Number:');
  json.UpdateString('labels[0].value','INV-2026-0500');
  json.UpdateString('labels[1].label','Invoice Date:');
  json.UpdateString('labels[1].value','April 2, 2026');
  json.UpdateString('labels[2].label','customer');
  json.UpdateString('labels[2].value','Contoso Ltd');
  json.UpdateString('labels[3].label','Total Due:');
  json.UpdateString('labels[3].value','$1,999.99');

  jsonOut := TJsonObject.Create;
  success := pdf.TextReplace('apply',json,jsonOut);
  if (success = False) then
    begin
      WriteLn('Not applied: ' + jsonOut.Emit());
      if (success = False) then
        begin
          WriteLn(pdf.LastErrorText);
          Exit;
        end;
    end;

  i := 0;
  count_i := jsonOut.SizeOfArray('replacements');
  while i < count_i do
    begin
      jsonOut.I := i;
      WriteLn('Replaced the value of "' + jsonOut.StringOf('replacements[i].label') + '" on page ' + jsonOut.StringOf('replacements[i].pages'));
      i := i + 1;
    end;

  success := pdf.WriteFile('qa_output/invoice_reissued.pdf');
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;

  //  Read the new values back with ExtractText's label option.
  jsonRead := TJsonObject.Create;
  jsonText := TJsonObject.Create;
  jsonRead.UpdateString('label','Total Due');
  jsonRead.UpdateString('labelValue','right');
  success := pdf.ExtractText('text',jsonRead,jsonText);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('Total Due is now: ' + jsonText.StringOf('text'));

  //  Sample output:

  //  Replaced the value of "Invoice Number:" on page 1
  //  Replaced the value of "Invoice Date:" on page 1
  //  Replaced the value of "customer" on page 1
  //  Replaced the value of "Total Due:" on page 1
  //  Total Due is now: $1,999.99


  pdf.Free;
  json.Free;
  jsonOut.Free;
  jsonRead.Free;
  jsonText.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.