[Tex/LaTex] Redefine `\section` so it behaves exactly* as `\section` except leaves out the number

sectioningstarred-versiontable of contents

There's any number of variations on the question "How do I get my unnumbered sections into the table of contents?" …

and none of the answers are any good to me, because they all involve sticking \addcontentsline, plus maybe other stuff (\mark, \phantomsection, …?), at just the right place in the document. In my case, the \section* commands are being issued by packages, and they don't give me hooks to insert stuff at just the right place; and also it is unclear exactly what set of "other stuff" I need. It would be simpler and more robust if I could just redefine \section* so that it behaves exactly as its non-starred version does, except that it does not print a section number.

How do I do that?

Note: KOMA-Script classes are not an option. I am currently using plain article for drafts and I will eventually need to drop in a journal's class.

Note 2 (from comments on an attempted answer): adjusting \secnumdepth globally will not work for me, because (a) I still want normal section numbering from unstarred \section etc, and (b) the packages that are issuing \section* commands can't be persuaded to use plain \section instead.

Best Answer

You can redefine \section to capture and condition on when the starred-version is used. Upon finding \section*, issue it just like you would \section, but remove the number-printing mechanism through an appropriate setting of the counter secnumdepth.

\documentclass{article}

\usepackage{xparse}

\let\oldsection\section
\makeatletter
\newcounter{@secnumdepth}
\RenewDocumentCommand{\section}{s o m}{%
  \IfBooleanTF{#1}
    {\setcounter{@secnumdepth}{\value{secnumdepth}}% Store secnumdepth
     \setcounter{secnumdepth}{0}% Print only up to \chapter numbers
     \oldsection{#3}% \section*
     \setcounter{secnumdepth}{\value{@secnumdepth}}}% Restore secnumdepth
    {\IfValueTF{#2}% \section
       {\oldsection[#2]{#3}}% \section[.]{..}
       {\oldsection{#3}}}% \section{..}
}
\makeatother

\begin{document}

\tableofcontents

\section{TestA}

\section*{TestB}

\end{document}

xparse provides an easy interface for (re)defining commands that may have a starred version, as well as an optional argument.

Related Solutions

[Tex/LaTex] Fix for amsart.cls tableofcontents bug regarding starred sections

carsten's answer -- that this is ams style -- is correct.

in the next update of the ams-latex collection, the amsclass manual will contain an appendix laying out the differences between the ams classes and the basic latex equivalents. but the inclusion of starred headings in the toc will not change.

to get rid of unwanted entries from the table of contents, see this entry in the ams author faq: http://www.ams.org/faq?faq_id=238 . kindly take note that the way \SkipTocEntry is defined depends on whether or not the hyperref package is being used. (we will consider including such a command -- with a safeguard to handle presence or absence of hyperref -- in the upgrade, which, if all goes well, is expected to be scheduled for later this year.)

[Tex/LaTex] Unnumbered sections and section marks

Issue the appropriate \markboth command when doing \section*; the easiest method, without plunging in the depth of the definition of \@startsection, which won't probably work with titlesec, is to redefine \section with the help of xparse:

\documentclass[12pt]{article}

\usepackage[compact]{titlesec}
\usepackage{fancyhdr}
\usepackage{lipsum}

\usepackage{xparse}
\let\CLASSsection\section

\RenewDocumentCommand{\section}{som}{%
  \IfBooleanTF{#1}
   {% there's a *
    \CLASSsection*{#3}\markboth{#3}{}%
   }
   {% no *
    \IfNoValueTF{#2}
     {% no opt arg
      \CLASSsection{#3}%
     }
     {% opt arg
      \CLASSsection[#2]{#3}%
     }%
   }%
}

\makeatletter
% fix \tableofcontents
\renewcommand{\tableofcontents}{%
  \section*{\contentsname}%
  \@starttoc{toc}%
}
\makeatother


% -----------------------------------------------------------------------------
\pagestyle{fancy}
\fancyhf{} % clear all header and footers
\renewcommand{\sectionmark}[1]{\markboth{\thesection\ #1}{}}
\renewcommand{\subsectionmark}[1]{\markright{\thesubsection\ #1}}

\fancyhead[L]{%
  \bfseries\begin{tabular}{@{}l@{}}\mbox{}\leftmark\\ \mbox{}\rightmark\end{tabular}%
}
\fancyhead[R]{\thepage}
\fancyfoot[L]{%
  \bfseries\begin{tabular}{@{}l@{}}\mbox{}\leftmark\\ \mbox{}\rightmark\end{tabular}%
}
\fancyfoot[R]{\thepage}
\renewcommand{\headrulewidth}{0.4pt}
\renewcommand{\footrulewidth}{0.4pt}

\setlength{\headheight}{30pt}

\begin{document}
\tableofcontents
\clearpage
\section{Section1}
\lipsum[4-8]
\newpage
\section*{Section2}
\lipsum[4-8]
\newpage
\section{Section3}
\lipsum[4-8]
\newpage
\section*{Section4}
\lipsum[4-8]
\end{document}

I've also redefined how you set the headers and footers; a tabular is surely better than having loads of Underfull \hbox messages when there's no right mark to typeset. Also \tableofcontents needs to be redefined, because it normally issues \@mkboth (an alias for \markboth).

Don't forget to follow fancyhdr's advice about increasing the \headheight; with this setting it requires just a bit less than 30pt.

Best Answer

Related Solutions

[Tex/LaTex] Fix for amsart.cls tableofcontents bug regarding starred sections

[Tex/LaTex] Unnumbered sections and section marks

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