Add texte before headings numbers (KOMA)

Question

I'm using the KOMA class scrbook, and trying to add some text before any section and subsection title. Like that :

\section{Hello !} must display Section 1 : Hello ! (1 is the normal counter). The same with "Subsection # :" before any section title.

So I tried the following code :

\renewcommand{\thesection}{Section \@arabic\c@section}

The snag is that I want to have those section/subsection title centered, so I added the parameter \centering when defining my headings font :

\addtokomafont{disposition}{\HeadingFont\centering}

But with this code, only the very name of the section is centered, but not the prefix "section 1". It is a problem when I have long titles, the page lacks balance. Can I try with \othersectionlevelsformat, like indicated in the manual, or have you another solution ?

As a bonus, have you a quick way to fix the table of contents, because the dots are encroaching the added text. I manually tried something with :

\renewcommand\l@section{\@dottedtocline{1}{1.5em}{4.2em}}

Answer 1

Update regarding KOMA-Script version 3.28:

Redefine \raggedsection and \sectionlinesformat to center the section titles including the numbers:

\documentclass[numbers=noenddot]{scrbook}
%\providecommand*\Ifstr{\ifstr}% needed up to and including KOMA-Script version 3.27, see https://komascript.de/faq_deprecatedif
\usepackage{blindtext}
\let\raggedsection\centering
\let\raggedchapter\raggedright

\renewcommand\sectionformat{Section~\thesection:\enskip}
\renewcommand\subsectionformat{Subsection~\thesubsection:\enskip}
\renewcommand\subsubsectionformat{Subsubsection~\thesubsection:\enskip}

\renewcommand*\sectionlinesformat[4]{#3#4}

\DeclareTOCStyleEntry[
  dynnumwidth,
  entrynumberformat=\entrywithprefix{Sect.}
]{default}{section}
\DeclareTOCStyleEntry[
  dynnumwidth,
  entrynumberformat=\entrywithprefix{Subs.}
]{default}{subsection}
\DeclareTOCStyleEntry[
  dynnumwidth,
  entrynumberformat=\entrywithprefix{Subsubs.}
]{default}{subsubsection}

\newcommand*\entrywithprefix[2]{%
  \def\autodot{}%
  \mbox{#1\,#2:}%
}

\begin{document}
\tableofcontents
\chapter{First chapter}
\blindtext
\section{First section}
\blindtext
\subsection{a rabbit subsection with quite a few words to make it
extra long not only because ducks are so cute}
\Blindtext
\blinddocument
\end{document}

---

---

Original answers (2015):

You could redefine \raggedsection, \raggedchapter and \othersectionlevelsformat (for version 3.17 or newer see the update below):

\let\raggedsection\centering
\let\raggedchapter\raggedright

\renewcommand\othersectionlevelsformat[3]{%
  \ifstr{#1}{section}{Section~#3:\enskip}{%
    \ifstr{#1}{subsection}{Subsection~#3:\enskip}{%
      #3\autodot\enskip}}}

To centr the section and subsection titles including the numbers use

\makeatletter
\addtokomafont{section}{\let\@hangfrom\relax}
\addtokomafont{subsection}{\let\@hangfrom\relax}
\makeatother

If the entries in the table of contents should also be changed redefine \addsectiontocentry and \addsubsectiontocentry additionally:

\renewcommand\addsectiontocentry[2]{%
  \ifstr{#1}{}{%
    \addtocentrydefault{section}{}{#2}}{%
    \addtocentrydefault{section}{Sect.\,#1:}{#2}}}
\renewcommand\addsubsectiontocentry[2]{%
  \ifstr{#1}{}{%
    \addtocentrydefault{subsection}{}{#2}}{%
    \addtocentrydefault{subsection}{Subs.\,#1:}{#2}}}

To get more space for the numbers you could enlarge the tocnumwidth for section and subsection (needs the up to date KOMA-Script version 3.15)

\RedeclareSectionCommand[tocnumwidth=5em]{section}
\RedeclareSectionCommand[tocnumwidth=5.5em]{subsection}

Code:

\documentclass[numbers=noenddot]{scrbook}
\usepackage{blindtext}
\let\raggedsection\centering
\let\raggedchapter\raggedright

\makeatletter
\addtokomafont{section}{\let\@hangfrom\relax}
\addtokomafont{subsection}{\let\@hangfrom\relax}
\makeatother

\renewcommand\othersectionlevelsformat[3]{%
  \ifstr{#1}{section}{Section~#3:\enskip}{%
    \ifstr{#1}{subsection}{Subsection~#3:\enskip}{%
      #3\autodot\enskip}}}

\renewcommand\addsectiontocentry[2]{%
  \ifstr{#1}{}{%
    \addtocentrydefault{section}{}{#2}}{%
    \addtocentrydefault{section}{Sect.\,#1:}{#2}}}
\renewcommand\addsubsectiontocentry[2]{%
  \ifstr{#1}{}{%
    \addtocentrydefault{subsection}{}{#2}}{%
    \addtocentrydefault{subsection}{Subs.\,#1:}{#2}}}

\RedeclareSectionCommand[tocnumwidth=5em]{section}
\RedeclareSectionCommand[tocnumwidth=5.5em]{subsection}

\begin{document}
\tableofcontents

\chapter{First chapter}
\blindtext
\section{First section}
\blindtext
\subsection{a rabbit subsection with quite a few words to make it
extra long not only because ducks are so cute}
\Blindtext
\blinddocument
\end{document}

---

Update regarding \othersectionlevelsformat and KOMA-Script Version 3.17 or newer

Note that KOMA-Script Version 3.17 uses \sectionformat, \subsectionformat etc. instead \othersectionlevelsformat. So you have to redefine this commands instead of \othersectionlevelsformat

\renewcommand\sectionformat{Section~\thesection:\enskip}
\renewcommand\subsectionformat{Subsection~\thesubsection:\enskip}

If the code should work with both the older versions (3.15 and 3.16) and version 3.17 or newer you can use

\renewcommand\othersectionlevelsformat[3]{%
  \ifstr{#1}{section}{Section~#3:\enskip}{%
    \ifstr{#1}{subsection}{Subsection~#3:\enskip}{%
      #3\autodot\enskip}}}

\providecommand*\sectionformat}{}
\providecommand*{\subsectionformat}{}
\renewcommand\sectionformat{Section~\thesection:\enskip}
\renewcommand\subsectionformat{Subsection~\thesubsection:\enskip}

Answer 2

I have absolutely no idea what you want to achieve, but this should give you a good start:

\documentclass{scrbook}
\addtokomafont{disposition}{\itshape}
\let\raggedsection\centering
\makeatletter
\renewcommand{\thesection}{Section \@arabic\c@section}
\renewcommand{\thesubsection}{Subsection \@arabic\c@subsection}
\makeatother
\usepackage{tocstyle}
\usetocstyle{KOMAlike}
\begin{document}
\tableofcontents
\chapter{gaspalet}
\section{a duck section}
\label{duck}
\subsection{a rabbit subsection with quite a few words to make it
extra long not only because ducks are so cute}
See \ref{duck}


\end{document}