Hints and tricks for Oracle and other stuff...

procedure Captcha (
  name_array  in owa.vc_arr,
  value_array in owa.vc_arr
) is
 pt raw(100);
 l_lob blob;
 vt varchar2(100);
 FUNCTION namedParam(
  p_searchVal   in varchar2,
  p_name_array  in owa.vc_arr,
  p_value_array in owa.vc_arr
  ) RETURN varchar2 IS
  i integer;
 BEGIN
  FOR i IN 1..nvl(p_name_array.count,0) LOOP
    if p_name_array(i)=p_searchVal then
      return p_value_array(i);
    end if;
  END LOOP;
  return null;
 END;
begin
pt := namedParam(
  'pt',
  name_array ,
  value_array
  );
pt := utl_encode.base64_decode(pt);
vt := utl_raw.cast_to_varchar2(pt);
l_lob := dd_bmp.captcha(vt);
owa_util.mime_header( 'image/bmp', FALSE );
htp.p('Content-length: '  dbms_lob.getlength( l_lob ));
owa_util.http_header_close;
wpg_docload.download_file( l_lob );

end;

procedure TestCaptcha (
  name_array  in owa.vc_arr,
  value_array in owa.vc_arr
)
as
 x raw(100);
 vcapchapreveri raw(100);
 vcapchavrednost raw(100);
 v varchar2(100);
begin
    for i__ in 1..nvl(name_array.count,0) loop
      if name_array(i__) = 'capchavrednost' then vcapchavrednost := value_array(i__);
      elsif name_array(i__) = 'capchapreveri' then vcapchapreveri := utl_raw.cast_to_raw(value_array(i__));
      end if;
    end loop;
begin

if utl_encode.base64_encode(vcapchapreveri) = vcapchavrednost then
  htp.p ('OK<BR>');
else
  htp.p ('NOT OK<BR>'); 
end if;

exception when others then null;
  htp.p ('NOT OK<BR>'); 
end;
 v := dd_random.rndchardd_random.rndchardd_random.rndchardd_random.rndchar;

 x := utl_raw.cast_to_raw(v);
 x := utl_encode.base64_encode(x);

htp.p('


<form method=post>
<img src="p_htmldokumenti.capcha?pt='x'">
<input type="text" name="capchapreveri" value="" size="4" maxlength="4">
<input type="hidden" name="capchavrednost" value="'x'">

<input type="submit" name="nnnn" value="Preveri">
</form>
');

exception when others then htp.p(sqlerrm);
end;