Lazarus Pascal Requires Chilkat v11.7.0+

Replace the Second (or Every) Occurrence of a Label in a PDF

See more PDF Text Replacement Examples

Demonstrates the "occurrence" member of a label entry. By default the first occurrence of a label, in reading order across the selected pages, is replaced; "occurrence" can be a number for the nth, or "all" for every occurrence. The invoice template has "Ref:" twice. 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;

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_template.pdf

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

  json := TJsonObject.Create;
  jsonOut := TJsonObject.Create;

  //  This template's {{placeholders}} are not being filled here: "keep" leaves them as they are
  //  (the default, "error", would refuse to apply while a placeholder on the page has no value).
  json.UpdateString('unusedPlaceholders','keep');

  //  "Ref:" appears twice on the page (A-1 near the top, A-2 below the totals).
  //  The default replaces the first occurrence only.
  json.UpdateString('labels[0].label','Ref:');
  json.UpdateString('labels[0].value','B-7');
  success := pdf.TextReplace('check',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('default: ' + jsonOut.IntOf('replacements[0].count') + ' occurrence replaced');

  //  The second occurrence only.
  json.UpdateString('labels[0].occurrence','2');
  success := pdf.TextReplace('check',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('occurrence 2: ' + jsonOut.IntOf('replacements[0].count') + ' occurrence replaced');

  //  Every occurrence.
  json.UpdateString('labels[0].occurrence','all');
  success := pdf.TextReplace('apply',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('occurrence all: ' + jsonOut.IntOf('replacements[0].count') + ' occurrences replaced');

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

  //  Sample output:

  //  default: 1 occurrence replaced
  //  occurrence 2: 1 occurrence replaced
  //  occurrence all: 2 occurrences replaced


  pdf.Free;
  json.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.