Lazarus Pascal Requires Chilkat v11.7.0+

Extract the Values of PDF Form Fields

See more PDF Text Extraction Examples

Demonstrates the "formFields" filter. The values of AcroForm fields (text fields, choices, check boxes) are not part of the page's text and are left out by default; "include" places each value at its field's position in the reading order, where a label capture can pick it up. 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 filled-in form used in this example is available at filled_form.pdf

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

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

  //  By default only the page's own text is returned: the captions, without the values typed into the fields.
  json.UpdateString('layout','lines');
  success := pdf.ExtractText('text',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('---- default ----');
  WriteLn(jsonOut.StringOf('text'));

  //  With formFields included, each field's value appears where the field is on the page.
  //  A checked check box appears as [x]; an unchecked one has no value.
  json.UpdateString('formFields','include');
  success := pdf.ExtractText('text',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('---- formFields: include ----');
  WriteLn(jsonOut.StringOf('text'));

  //  A field value can be captured by the caption beside it, as for any other text.
  json.UpdateString('label','Email');
  success := pdf.ExtractText('text',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf.LastErrorText);
      Exit;
    end;
  WriteLn('Email: ' + jsonOut.StringOf('text'));

  //  Sample output:

  //  ---- default ----
  //  Membership Application
  //  Name:
  //  Email:
  //  Phone:
  //  Newsletter: Yes, send me the monthly newsletter
  //  Volunteer: I am willing to volunteer
  //  ---- formFields: include ----
  //  Membership Application
  //  Name: Dana Whitfield
  //  Email: dana.whitfield@example.com
  //  Phone: 555-0142
  //  Newsletter: [x] Yes, send me the monthly newsletter
  //  Volunteer: I am willing to volunteer
  //  Email: dana.whitfield@example.com


  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.