Create new section commands (with correct TOC entries) in KOMA-Script

Question

What is needed to make a new sectioning command which outputs a correct entry in the TOC?

For example, a command \foo which outputs something similar to \subsection in the TOC (and in the main document). After a few trial and error, I thought that just copying the definition of \subsection and defining the needed commands (the foo counter, \thefoo command, \addfootocentry, \foomarkformat, \foomark). But it seems that it's not enough.

Here is a minimal (non) working example.

\documentclass[DIV12]{scrartcl}

\makeatletter
\newcommand*{\foonumdepth}{\tw@}
\newcounter{foo}[section]
\renewcommand*{\thefoo}{\thesection.\@arabic\c@foo}
\newcommand*\foomarkformat{\thefoo\autodot\enskip}
\newcommand*{\addfootocentry}[2]{%
  \addtocentrydefault{foo}{#1}{#2}%
}
\newcommand\foomark[1]{\markright{#1}}
\newkomafont{foo}{\normalfont\normalsize}
\newcommand\foo{%
 \@startsection{foo}%
  {\foonumdepth}%
  {\z@}%
  {-\baselineskip}%
  {\baselineskip}%
  {\ifnum \scr@compatibility>\@nameuse{scr@[email protected]}\relax
   \setlength{\parfillskip}{\z@ plus 1fil}\fi
   \raggedsection\normalfont\sectfont\nobreak\size@subsection\usekomafont{foo}}%
}
%\def\foo#1{}
\makeatother

\begin{document}
\tableofcontents

\noindent\hrulefill

\section{One}
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
\subsection{SubOne}
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
\foo{FooOne}
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
\subsection{Two}
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
\end{document}

More and more

Added: I think this belongs to the same question, because it's, in a way, what I'm trying to achieve: how can I create a sectioning command \@startsection named section but on a different level (If I change \sectionlevel command… I still get the same output in the table of contents: it's like this command does not influence in anything).

And this is probably a different question… but is there a way to tell KOMA-Script that I want to include in the TOC only the levels until \subsection unnumbered (\setcounter{secnumdepth}{2}\setcounter{tocdepth}{2}) but I want, e.g., numbered \subsubsections (which are not in the TOC)?

EDIT

I'm not sure if this needs to be clarified… but I'm thinking that this might be an XY Problem. I came across this question because I'm writting a document where are certain points which I need to address:

• I want to make a document which has four sectioning levels. Part, Foo (and Bar), Section and Subsection.
• As you see, the second level has two different commands. Each Foo or Bar, has it's own Sections or Subsections (i.e., they restart the counter).
• Part, and Foo and Bar, should not be numbered. And Section and Subsection should be numbered.
• Moreover, Part should add a line to the TOC with the style of the default \section (I thought that just changing the \@startsection{…}{\@ne}… would suffice, but It seems not), and Foo/Bar should add a line to the TOC with the style of the default \subsection.

Of course, I can address this with what I consider “hackish”. And I came trough this question. E.g., is it possible to create a parallel sectioning command to \subsection which behaves correctly? How can I make it?

Answer 1

The question is a bit confusing. Parts that look like section, two parallel document structures. I cannot imagine a use case, that's why it is hard to implement.

Anyway, i think with a recent KOMA-version, you should be able quite easily to achieve your goal.

I just copied the default values from the KOMA-guide.

\documentclass{scrartcl}
\DeclareSectionCommand[
    afterskip=1.5ex plus .2ex,
    beforeskip=-3.25ex plus -1ex minus -.2ex,
    indent=0pt,
    level=2,
    font=\usekomafont{subsection},
    tocindent=1.5em,
    tocnumwidth=2.3em,
    counterwithin=section,
style=section]{foo}
\begin{document}
\tableofcontents
\section{Wombat}
\subsection{Walzing}
\foo{Wobbling}
\end{document}

Answer 2

This addresses only (via a hack) your second question about dropping the numbering of section and subsection. I am not really satisfied with this kind, but it works (somehow)

I redefined the section command (and subsection) to use the starred version, which does make an entry to toc and added the toc entry manually, dropping the section level numbering there.

\documentclass[DIV12]{scrartcl}
\usepackage{blindtext}%
\usepackage{etoolbox}%

\usepackage{tocloft}% For \cftpagenumber...

\let\LaTeXStandardSection\section%
\renewcommand{\section}[1]{%
\begingroup % Limit the renewcommand of \thesection
\renewcommand{\thesection}{}%  
\refstepcounter{section}%
\addcontentsline{toc}{section}{\protect{\numberline{\thesection}{#1}}}
\LaTeXStandardSection*{\arabic{section} #1}
\endgroup
}%



\let\LaTeXStandardSubSection\subsection%
\renewcommand{\subsection}[1]{%
\par
\begingroup
\renewcommand{\thesubsection}{}%
\refstepcounter{subsection}%
\addcontentsline{toc}{subsection}{\protect{\numberline{\thesubsection}{#1}}}%\hspace*{0em}
\vspace{\baselineskip}
\LaTeXStandardSubSection*{\thesection.\arabic{subsection} #1}%
\endgroup%
}

%Enlarge the spacing a little bit
\pretocmd{\subsubsection}{\vspace{0.5\baselineskip}}

\newcounter{foo}[section]
\newcounter{subsectionsavecounter}


\newcommand{\foo}[1]{%
\setcounter{subsectionsavecounter}{\number\value{subsection}}
\setcounter{subsection}{\number\value{foo}}   
%\refstepcounter{foo}% Increase before if patched `\subsection` is used
% Use the 'patched' \subsection command if no number entry to TOC should 
% be done!
%\subsection{FOO #1}%
\LaTeXStandardSubSection{FOO #1}  %  Remove the FOO later one!
\refstepcounter{foo}% Increase afterwards if \LaTeXStandardSubSection is to be used. 
\setcounter{subsection}{\number\value{subsectionsavecounter}}%
}

% If the page numbers of sections and subsections should not appear, remove the % 
%\cftpagenumbersoff{section}% 
%\cftpagenumbersoff{subsection}% 

\begin{document}

\tableofcontents

\noindent\hrulefill

\section{One}
\blindtext
\subsection{SubOne}
\blindtext
\foo{One of some ones}

\subsection{Two}
\blindtext[2]
\subsubsection{First subsubsection ever}
\blindtext[3]

\newpage

\section{Another One}

\subsection{Yet another subsection from 2nd section}
\blindtext[1]
\subsubsection{First subsub of first sub of 2nd section}
\blindtext[2]
\foo{Yet another one of some ones}


\end{document}

I do not have a solution for your foo environment, instead of grabbing the section command as well and using an intermediate different counter for that.

EDIT I grabbed the subsection command and fooed it ;-)

Removing the section/subsection numbers looks awkward, in my point of view...

Answer 3

I found the problem, I need to define the \l@foo command, which is the one in charge of adding the line of contents. In scrartcl.cls you can see hoy are defined each of the \l@… for each level. In my case, it's easier. Since I want it to add a line with the exact same style as \section (or whatever), it's just needed to do a

\let\l@foo\l@section

and \foo will output the exact line in TOC as \section.