Making a list optional in template .cls file

Question

I have the following code in my .cls file for my resume.

    \newenvironment{rSubsection}[4]{ % 4 input arguments - company name, year(s) employed, job title and location
     {\bf #1} \hfill {#2} % Bold company name and date on the right
     \ifthenelse{\equal{#3}{}}{}{ % If the third argument is not specified, don't print the job title and location line
      \\
      {\em #3} \hfill {\em #4} % Italic job title and location
      }\smallskip
      \begin{list}
      {$\cdot$}{\leftmargin=1.0em} % \cdot used for bullets, no indentation
       \itemsep -0.5em \vspace{-0.5em} % Compress items in list together for aesthetics
      }{
      \end{list}
      \vspace{0.5em} % Some space after the list of bullet points
    }

Note the \begin{list}. This expects a \item in the latex file. Failing to provide an \item throws the following error:

LaTeX Error: Something's wrong--perhaps a missing \item.

How can make having a list optional?

score 2 · Answer 1 · answered Aug 29 '17 at 18:06

The following uses two packages to get around your requirement:

environ provides the means to capture the body of an environment inside a macro \BODY. This way we can rewrite each environment as a macro, which is sometimes easier when wanting to manage the content between \begin and \end.
etoolbox provides \patchcmd{<cmd>}{<search>}{<replace>}{<success>}{<failure>}. I've used it to replace \item with \item (effectively doing nothing) with the \BODY of the environment and allows one to condition on whether or not this replacement is <success>ful or not.

\documentclass{article}

\usepackage{etoolbox,environ}

\NewEnviron{rSubsection}[4]{% 4 input arguments - company name, year(s) employed, job title and location
  {\bfseries #1} \hfill #2 % Bold company name and date on the right
  % https://tex.stackexchange.com/q/263733/5764
  \if\relax\detokenize{#3}\relax\else % If the third argument is not specified, don't print the job title and location line
    \par
    {\itshape #3 \hfill #4} % Italic job title and location
  \fi\par\smallskip
  % \patchcmd{<cmd>}{<search>}{<replace>}{<success>}{<failure>}
  \patchcmd{\BODY}{\item}{\item}{%
    \list
      {$\cdot$}
      {\leftmargin=1.0em % \cdot used for bullets, no indentation
      \itemsep -0.5em \vspace{-0.5em}} % Compress items in list together for aesthetics
      \BODY
    \endlist
  }{}%
  \vspace{0.5em} % Some space after the list of bullet points
}

\begin{document}

\begin{rSubsection}{First}{Second}{Third}{Fourth}
  \item First item
  \item Second item
  \item Third item
  \item Last item
\end{rSubsection}

\begin{rSubsection}{First}{Second}{}{Fourth}
  \item First item
  \item Second item
  \item Third item
  \item Last item
\end{rSubsection}

\begin{rSubsection}{First}{Second}{Third}{Fourth}
\end{rSubsection}

\end{document}

Making a list optional in template .cls file

1 Answers1