Superscript cross references to an appendix

Question

I'm writing a report and I'd like to use superscript references (like I'm already using for the bibliography) to link to a section withing an \appendix so it appears as a superscript with brackets like [A.1] or [A.2] (to match the section I'm pointing).

All I've been able to do is the following:

\documentclass[12pt,a4paper]{article}
\usepackage[hidelinks]{hyperref}
%a million other packages

\begin{document}

Text see annex 1\ref{ref:a}

\appendix
\section{title of annex}
information\label{ref:a}

\end{document}

This works well enough, except it only displays an A without brackets with the same size as the text. Any ideas?

Answer 1

The cross -reference format is stored for a counter, named, say foo, as as \p@foo\csname thefoo\endcsname, basically always \p@foo is empty, and \thefoo comes into action. The storage occurs in \refstepcounter as \@currentlabel.

Defining \p@foo as [] will only print [] before \thefoo, but not enclose it. \csname thefoo\endcsname has to 'gobbled' (captured with a special macro using it as delimiter, then [A.\thefoo] can be used.

In order to limit this effect to the appendix only, I've added it to the definition of \appendix with \g@addto@macro{\appendix}.

In my explanations replace foo with section, however.

\documentclass[12pt,a4paper]{article}
\usepackage[hidelinks]{hyperref}
%a million other packages

\makeatletter
\g@addto@macro\appendix{%
  \renewcommand{\thesection}{\arabic{section}}%
  \def\@gobblerefstuff#1\csname thesection\endcsname{%
    [A.\thesection]}%
  \renewcommand{\p@section}{\@gobblerefstuff}
}
\makeatother

\begin{document}

Text see annex \ref{ref:a} or \ref{Completelydifferent}



\appendix
\section{title of annex}
information\label{ref:a}

\section{And now for something completely different} \label{Completelydifferent}

\end{document}