Janilabo | Expand()

function Expand(trgt_pos: Integer; s1, s2, str: string): string;
var
  l, p, start, finish, s1L, s2L: Integer;
  tmp: string;
begin
  l := Length(str);
  s1L := Length(s1);
  s2L := Length(s2);
  if ((s1L > l) or (s2L > l) or (trgt_pos > l) or (trgt_pos < 1)) then
    Exit;
  finish := PosEx(s2, str, trgt_pos);
  if ((finish < 1) or (finish = trgt_pos)) then
    Exit;
  tmp := Copy(str, 1, trgt_pos);
  repeat
    p := PosEx(s1, tmp, (p + 1));
    if (p > 0) then
      start := p;
  until (p <= 0);
  if ((start <> trgt_pos) and (start > 0) and (finish > 0) and (start < finish)) then
    Result := Copy(str, (start + s1L), ((finish - start) - s2L));
  tmp := '';
end;

var
  str, tmp: string;
  id, id_pos: Integer;

begin
  ClearDebug;
  str := '<item_list>' + #13#10 +
         '  <item_data>' + #13#10 +
         '    <item_name>Apple</item_name>' + #13#10 +
         '    <item_category>Fruits</item_category>' + #13#10 +
         '    <item_ID>2</item_ID>' + #13#10 +
         '    <item_description>Great fruit</item_description>' + #13#10 +
         '  </item_data>' + #13#10 +
         '  <item_data>' + #13#10 +
         '    <item_name>Strawberry</item_name>' + #13#10 +
         '    <item_category>Berries</item_category>' + #13#10 +
         '    <item_ID>0</item_ID>' + #13#10 +
         '    <item_description>Sweet berry</item_description>' + #13#10 +
         '  </item_data>' + #13#10 +
         '  <item_data>' + #13#10 +
         '    <item_name>Tomato</item_name>' + #13#10 +
         '    <item_category>Vegetables</item_category>' + #13#10 +
         '    <item_ID>1</item_ID>' + #13#10
         '    <item_description>Healthy vegetable</item_description>' + #13#10 +
         '  </item_data>' + #13#10 +
         '</item_list>';
  for id := 0 to 2 do
  begin
    id_pos := Pos(('<item_ID>' + IntToStr(id) + '</item_ID>'), Between('<item_list>', '</item_list>', str));
    if (id_pos > 0) then
    begin
      tmp := Expand(id_pos, '<item_data>', '</item_data>', str);
      WriteLn('Item nr.' + IntToStr(id) + ':' + #13#10 +
              'Name: ' + Between('<item_name>', '</item_name>', tmp) + #13#10
              'Description: ' + Between('<item_description>', '</item_description>', tmp) + #13#10
              'Category: ' + Between('<item_category>', '</item_category>', tmp) + #13#10);
      tmp := '';
    end;
  end;
end.