Reference a table by caption created by ctable

Question

Fixed in the new version of ctable

ctan-ann: CTAN Update: ctable 26 May 2012

Might be a stupid question, but is there a way to reference, that means print, the caption of a ctable? hyperref has \nameref for sections, which works for normal floats, but not for ctable. This error is raised:

! Undefined control sequence.
<argument> \Hy@safe@activesfalse \@ctblcap
\relax
l.92 ...kewed towards commodity. \nameref{tab:ef4}

Min example:

\documentclass[pdftex,a4paper, 12pt, DIV12, BCOR10mm, bibliography=totoc]{scrreprt} %DIV, BCOR =Seitenränder
\usepackage{ctable}
\usepackage{hyperref}

\begin{document}

\ref{tab:table} %ok
\ref{tab:ctable} %ok
\autoref{tab:table} %ok
\autoref{tab:ctable} %ok
\nameref{tab:table} %ok 
\nameref{tab:ctable} %error


\begin{table}[h]
\centering
\begin{tabular}{|l|l}
hallo & bello\\
\end{tabular}
\caption{Table}
\label{tab:table}
\end{table}

\ctable[
caption = Ctable, label=tab:ctable,]{ll}
{}{
Hello & bello \LL
}

\end{document}

Answer 1

The problem based on the way how ctable wrote the information to the aux. There you can find the following relevant line:

\newlabel{tab:ctable}{{0.2}{1}{\@ctblcap \relax }{table.0.2}{}}

If you use \nameref{tab:ctable} the argument {\@ctblcap \relax } is called. However the command is undefined and it uses the special character @. Based on this information the first quick fix is:

\makeatletter
 \def\@ctblcap{Table}
 \nameref{tab:ctable} %error
\makeatother

On the other hand you can change the implementation of ctable:

\usepackage{etoolbox} %provided \expandonce
\makeatletter
\def\@ctblCaption{
   \ifx\@ctblcap\undefined\let\@ctblcap\@ctblcaption\fi
   \ifx\@ctblcaption\empty\else
      \def\@ctblcaptionarg{\ifx\@ctbllabel\empty\else\label{\@ctbllabel}\fi
         \@ctblcaption\ \@ctblcontinued\strut}
      \ifx\@ctblcap\empty
      \begingroup
        \edef\x{\endgroup\noexpand\caption[]{\expandonce\@ctblcaptionarg}}
        \x
      \else
      \begingroup
        \edef\x{\endgroup\noexpand\caption[\expandonce\@ctblcap]%
                                          {\expandonce\@ctblcaptionarg}}
        \x
      \fi
   \fi
}
\makeatother

The relevant part are the lines starting with \edef\x. E.g.:

\begingroup
 \edef\x{\endgroup\noexpand\caption[]{\expandonce\@ctblcaptionarg}}
\x

whereby the original code was:

\caption[]{\@ctblcaptionarg}

The command caption doesn't expand the information of its arguments. So in the aux file you have the entry \@ctblcaptionarg. Instead of a complete expansion of \@ctblcaptionarg I used \expandonce which is more robust in this case.

The complete MWE:

\documentclass{scrreprt} %DIV, BCOR =Seitenränder
\usepackage[]{ctable}
\usepackage{etoolbox}
\usepackage{hyperref}

\makeatletter
\def\@ctblCaption{
   \ifx\@ctblcap\undefined\let\@ctblcap\@ctblcaption\fi
   \ifx\@ctblcaption\empty\else
      \def\@ctblcaptionarg{\ifx\@ctbllabel\empty\else\label{\@ctbllabel}\fi
         \@ctblcaption\ \@ctblcontinued\strut}
      \ifx\@ctblcap\empty
      \begingroup
        \edef\x{\endgroup\noexpand\caption[]{\expandonce\@ctblcaptionarg}}
         \x
      \else
      \begingroup
        \edef\x{\endgroup\noexpand\caption[\expandonce\@ctblcap]%
                                          {\expandonce\@ctblcaptionarg}}
        \x
      \fi
   \fi
}
\makeatother

\begin{document}
\begin{verbatim}
\ref{tab:table} %ok
\autoref{tab:table} %ok
\nameref{tab:table} %ok 
\end{verbatim}
\ref{tab:table} %ok
\autoref{tab:table} %ok
\nameref{tab:table} %ok 


\begin{verbatim}
\ref{tab:ctable} %ok
\autoref{tab:ctable} %ok
\nameref{tab:ctable} %error
\end{verbatim}
\ref{tab:ctable} %ok
\autoref{tab:ctable} %ok
\nameref{tab:ctable} %error

\begin{table}[h]
\centering
\begin{tabular}{|l|l}
hallo & bello\\
\end{tabular}
\caption{Table}
\label{tab:table}
\end{table}

\ctable[caption = Ctable, label=tab:ctable,]{ll}{}{
Hello & bello \LL}

\end{document}

I think you should write bug report to the author of ctable.