Question

When an ini file contains a section with only one key (like MySection1 in

[MySection1]
MyKey1=MyValue1
[MySection2]
...

) calling DeleteKey for that key leaves an empty section:

[MySection1]
[MySection2]
...

I’d prefer if that empty section would be removed too. Of course I can call something like

if not ini.SectionExists('MySection1') then
  ini.EraseSection('MySection1');

after every call to DeleteKey (or make an overridden TExtIniFile.DeleteKey do that) but I hope there is an automatic way to make Windows or the VCL do that. Do you know any?

Update: I’m using a TIniFile descendant that solely adds some additional Read*/Write* methods.

Update: My test routine:

procedure TForm1.Button1Click(Sender: TObject);
var
  ini: TMyIniFile;
begin
  ini := TMyIniFile.Create(cIniFileName);
  try
    ini.WriteString('MySection1', 'MyKey1', 'MyValue1');
    ini.DeleteKey('MySection1', 'MyKey1');
  finally
    ini.Free;
  end;

  Show;
end;

procedure TForm1.Show;
begin
  if FileExists(cIniFileName) then
    Memo1.Lines.LoadFromFile(cIniFileName)
  else
    Memo1.Lines.Clear;
end;

TMyIniFile can be an alias for TIniFile or a descendant of TMemIniFile with an destructor calling UpdateFile.

Answer 1

I don’t think there is “automatic way to make Windows or the VCL do that”. I believe that the reason is that “API” doesn’t know that you don’t intend to use that section anymore (ie if the API would delete the section after you delete the last key someone would complain that this is inefficient as they intend to add an key to that section later and so the section must be recreated). Also, one could argue that the existence of the empty section carries information too and thus that information would be lost in case of automatic deletion.