Delphi DLL 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. Delphi DLL

var
success: Boolean;
pdf: HCkPdf;
json: HCkJsonObject;
jsonOut: HCkJsonObject;

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 := CkPdf_Create();
success := CkPdf_LoadFile(pdf,'qa_data/pdf/invoice_template.pdf');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

json := CkJsonObject_Create();
jsonOut := CkJsonObject_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).
CkJsonObject_UpdateString(json,'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.
CkJsonObject_UpdateString(json,'labels[0].label','Ref:');
CkJsonObject_UpdateString(json,'labels[0].value','B-7');
success := CkPdf_TextReplace(pdf,'check',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;
Memo1.Lines.Add('default: ' + IntToStr(CkJsonObject_IntOf(jsonOut,'replacements[0].count')) + ' occurrence replaced');

//  The second occurrence only.
CkJsonObject_UpdateString(json,'labels[0].occurrence','2');
success := CkPdf_TextReplace(pdf,'check',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;
Memo1.Lines.Add('occurrence 2: ' + IntToStr(CkJsonObject_IntOf(jsonOut,'replacements[0].count')) + ' occurrence replaced');

//  Every occurrence.
CkJsonObject_UpdateString(json,'labels[0].occurrence','all');
success := CkPdf_TextReplace(pdf,'apply',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;
Memo1.Lines.Add('occurrence all: ' + IntToStr(CkJsonObject_IntOf(jsonOut,'replacements[0].count')) + ' occurrences replaced');

success := CkPdf_WriteFile(pdf,'qa_output/invoice_refs.pdf');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

//  Sample output:

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

CkPdf_Dispose(pdf);
CkJsonObject_Dispose(json);
CkJsonObject_Dispose(jsonOut);