Delphi DLL Requires Chilkat v11.7.0+

Search a PDF with a Regular Expression

See more PDF Text Extraction Examples

Demonstrates searching a PDF with a regular expression (regex: true), limiting the number of results (maxResults), and matching whole words only (wholeWord). Delphi DLL

var
success: Boolean;
pdf: HCkPdf;
json: HCkJsonObject;
jsonOut: HCkJsonObject;
i: Integer;
count_i: Integer;

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 order_records.pdf

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

json := CkJsonObject_Create();
jsonOut := CkJsonObject_Create();

//  Find every order number.  With regex set to true, the query is a regular expression.
CkJsonObject_UpdateString(json,'query','ORD-[0-9]{4}-[0-9]{4}');
CkJsonObject_UpdateBool(json,'regex',True);
//  We only want the matched text, so no context is needed.
CkJsonObject_UpdateInt(json,'context',0);

success := CkPdf_ExtractText(pdf,'search',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

Memo1.Lines.Add('Order numbers found: ' + IntToStr(CkJsonObject_IntOf(jsonOut,'count')));
i := 0;
count_i := CkJsonObject_SizeOfArray(jsonOut,'matches');
while i < count_i do
  begin
    CkJsonObject_putI(jsonOut,i);
    Memo1.Lines.Add(CkJsonObject__stringOf(jsonOut,'matches[i].text'));
    i := i + 1;
  end;

//  Find the e-mail addresses, but stop after the first three.
CkJsonObject_UpdateString(json,'query','[a-z0-9._]+@[a-z]+[.][a-z]+');
CkJsonObject_UpdateInt(json,'maxResults',3);
success := CkPdf_ExtractText(pdf,'search',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

Memo1.Lines.Add('First three e-mail addresses:');
i := 0;
count_i := CkJsonObject_SizeOfArray(jsonOut,'matches');
while i < count_i do
  begin
    CkJsonObject_putI(jsonOut,i);
    Memo1.Lines.Add(CkJsonObject__stringOf(jsonOut,'matches[i].text'));
    i := i + 1;
  end;

//  wholeWord: true matches only whole words.  The word "cat" appears once in the PDF,
//  but it is also inside "catalog" and "category".
CkJsonObject_Delete(json,'maxResults');
CkJsonObject_UpdateBool(json,'regex',False);
CkJsonObject_UpdateString(json,'query','cat');
success := CkPdf_ExtractText(pdf,'search',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;
Memo1.Lines.Add('Occurrences of cat (any): ' + IntToStr(CkJsonObject_IntOf(jsonOut,'count')));

CkJsonObject_UpdateBool(json,'wholeWord',True);
success := CkPdf_ExtractText(pdf,'search',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;
Memo1.Lines.Add('Occurrences of cat (whole word): ' + IntToStr(CkJsonObject_IntOf(jsonOut,'count')));

//  Sample output:

//  Order numbers found: 9
//  ORD-2026-0301
//  ORD-2026-0302
//  ORD-2026-0303
//  ORD-2026-0304
//  ORD-2026-0305
//  ORD-2026-0306
//  ORD-2026-0307
//  ORD-2026-0308
//  ORD-2026-0307
//  First three e-mail addresses:
//  alice.moore@example.com
//  bkumar@example.org
//  carla@example.net
//  Occurrences of cat (any): 3
//  Occurrences of cat (whole word): 1

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