Footnote Citations in Beamer: How to use abbreviated alphabetic citations in place of footmarks?

Question

I am writing a presentation in beamer, and I would like citations to appear at the foot of the slide it appears on, along with on a final references page.

In a normal article, I would use abbreviated alphabetic citations that link to a references page at the end, and on this page will be a two column bibliography that contains, in each row, an abbreviated alphabetic citation in the first column along with the corresponding full citation in the second column.

I would like to adapt this style to the beamer class. To do so, I would like to replace standard footnote marks with these abbreviated alphabetic citations. This would mean that when the footnote is first called, and in all subsequent references to the footnote, the abbreviated alphabetic citation appears in place of the expected footmark. I have attached a mock up of how this would look.

This was achieved by brute force defining a single footnote mark. Below is the LaTeX code of how I achieved this example.

\documentclass{beamer}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{James,
  title={The representation theory of the symmetric groups},
  author={James, Gordon Douglas},
  volume={682},
  year={2006},
  publisher={Springer}
}
\end{filecontents}

\usepackage[style=alphabetic,backend=biber]{biblatex}
\bibliography{\jobname.bib}

\renewcommand{\thefootnote}{\fnsymbol{footnote}}
\makeatletter
\def\@fnsymbol#1{%
   \ifcase#1\or {\cite{James}}\fi
}%
\def\@makefnmark{\hbox{{{\usebeamercolor[fg]{footnote mark}\usebeamerfont*{footnote mark} \@thefnmark}}}}
\def\@makefntext#1{%
    \def\insertfootnotetext{\hphantom{\cite{James}}#1}%
    \def\insertfootnotemark{\@makefnmark}%
    \usebeamertemplate***{footnote}}    
\makeatother

\begin{document}
\begin{frame}{Frame Title}
\footnote{\fullcite{James}}
\end{frame}

\begin{frame}{Frame Title}
\printbibliography 
\end{frame}

\end{document}

This is a terrible way to do it since any further footnotes will cause an error as I have ran out of defined footnote symbols. I could manually define more footnote symbols, but then I would be limited to at most 9 footnotes (this is the limit for the number of distinct footnote symbols). This would also require me to manually define the order of my footnote symbols to match the order of the footnote citations. Moreover, it rules out the ability to use footnotes for anything other than footnote citations. I also had to manually define extra horizontal spacing at the start of \insertfootnotetext since the width of these appreciated alphabetic citations exceeds the width of the column allocated for footnote marks in the standard footnote environment.

I would be grateful if someone could help guide me towards a "proper" way of achieving this result.

Answer 1

I would create a new command using \cite and \fullcite combined, resetting the footnote number:

\documentclass{beamer}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{James,
  title={The representation theory of the symmetric groups},
  author={James, Gordon Douglas},
  volume={682},
  year={2006},
  publisher={Springer}
}
@book{booka,
  title={Another book},
  author={van Duck, Paulinho},
  volume={10},
  year={2020},
  publisher={Quack}
}
\end{filecontents}

\usepackage[style=alphabetic,backend=biber]{biblatex}
\bibliography{\jobname.bib}

\addtobeamertemplate{footnote}{\hskip -1.5em}{}
\newcounter{mycounter}

\newrobustcmd*{\myfootfullcite}[1]{%
      {% this parenthesis is needed to create a group
      \cite{#1}%
      \renewcommand\thefootnote{}%
      \footnote{%
          \setcounter{mycounter}{\value{footnote}}%
          \sbox0{\textsuperscript{\the\value{mycounter}}}%
          \hspace{-\the\wd0}%
          \cite{#1}~\fullcite{#1}}%
          \addtocounter{footnote}{-1}%
      }%
    }
      
\begin{document}
\begin{frame}{Frame Title}
\myfootfullcite{James}
An ordinary footnote\footnote{A footnote.}

Another citation \myfootfullcite{booka}
Another footnote\footnote{Another footnote.}
\end{frame}

\begin{frame}{Bibliography}
\printbibliography 
\end{frame}
\end{document}