[Tex/LaTex] Repeat the same reference in footnote on different pages

biblatexfootnotes

I'm using BibLaTeX to handle my bibliography and I want a reference to be placed in a footnote on every page where I cite the same work and have the same number. Also I want to be able to cite the same work on one page several times. The latter could be done by using the code from the Joseph Wright's blog. However, it puts a reference in a footnote only once.

Best Answer

There are a number of TeX.SE posts on Joseph's citation style. One of them asks about limiting the \ifciteseen to the current page. The accepted solution takes an excessive number of LaTeX runs to compile and doesn't sort footnotes.

The new citation command \sfcite defined in the document below addresses these limitations. It also correctly handles labelnumber prefixes and shorthands.

\documentclass{article}
\usepackage[style=numeric-comp,sorting=none,citetracker,pagetracker=page]{biblatex}
\usepackage[colorlinks]{hyperref}

\makeatletter
% user-level citation command
\DeclareCiteCommand{\sfcite}[\cbx@superscript]
  {\usebibmacro{cite:init}%
   \let\multicitedelim\supercitedelim
   \iffieldundef{prenote}{}{\BibliographyWarning{Ignoring prenote argument}}%
   \iffieldundef{postnote}{}{\BibliographyWarning{Ignoring postnote argument}}}
  {\usebibmacro{citeindex}%
   \usebibmacro{cite:super:foot}%
   \usebibmacro{cite:comp}}
  {}
  {\usebibmacro{cite:dump}}

% save instcount, save key and last inline instcount if seen first on page
\newbibmacro*{cite:super:foot}{%
  \xdef\cbx@key{\thefield{entrykey}}%
  \ifsamepage{\value{instcount}}{\csuse{cbx@instcount@\cbx@key}}{}{%
    \listxadd{\cbx@savelist}{\cbx@key}%
    \ifnumequal{\value{cbx@tempcntd}}{0}{%
      \defcounter{cbx@tempcntc}{\value{instcount}}%
      \loop\ifnum\value{cbx@tempcntc}>0
        \ifsamepage{\value{instcount}}{\value{cbx@tempcntc}}
          {\ifcsundef{blx@fnpage@\number\numexpr\value{cbx@tempcntc}}
             {\setcounter{cbx@tempcntd}{\value{cbx@tempcntc}}}{}%
           \stepcounter{cbx@tempcntc}}
          {\setcounter{cbx@tempcntc}{0}}%
      \repeat}{}}%
  \csnumgdef{cbx@instcount@\cbx@key}{\value{instcount}}}
\let\cbx@savelist\@empty
\newcounter{cbx@tempcntc}
\newcounter{cbx@tempcntd}
\setcounter{cbx@tempcntd}{0}

\newrobustcmd*{\cbx@superscript}[1]{%
  \global\toggletrue{cbx@sfcite}
  \mkbibsuperscript{#1}%
  \cbx@footnote%
  \global\togglefalse{cbx@sfcite}}
\newtoggle{cbx@sfcite}

\AtEveryCitekey{%
  \ifciteseen{}{\csnumgdef{cbx@instcount@\thefield{entrykey}}{-1}}%
  \iftoggle{cbx@sfcite}{}{\cbx@footnote}}
\AtEveryBibitem{\cbx@footnote}
\AtEveryLositem{\cbx@footnote}

% defer citation footnotes to last inline reference instance on page
\newrobustcmd*{\cbx@footnote}{%
  \ifboolexpr{ not test {\ifdefempty{\cbx@savelist}}
               and test {\ifnumequal{\value{instcount}}{\value{cbx@tempcntd}}} }
    {\cbx@sortlist@init%
     \let\do\cbx@do
     \dolistloop{\cbx@sortlist}%
     \global\let\cbx@savelist\@empty
     \setcounter{cbx@tempcntd}{0}}{}}

% print footnotes in 'sorting' order
\def\cbx@do#1{%
  \ifinlist{#1}{\cbx@savelist}
    {\begingroup
     \blx@resetdata
     \blx@getrefcontext{#1}%
     \blx@getdata@cite{#1}%
     \blx@setoptions@type\abx@field@entrytype
     \blx@setoptions@entry
     \blx@execute
     \blx@beglang
     \iffieldundef{shorthand}
       {\gdef\@thefnmark{\printfield{labelprefix}\printfield{labelnumber}}}
       {\gdef\@thefnmark{\printfield{shorthand}}}%
     \gappto\@thefnmark{\blx@initunit}%
     \ifhyperref
       {\H@@footnotetext{\blx@driver\abx@field@entrytype}}
       {\@footnotetext{\blx@driver\abx@field@entrytype}}%
     \blx@endlang
     \endgroup}
    {}}

% access internal list of sorted entry keys
\def\cbx@sortlist@init{%
  \global\letcs{\cbx@sortlist}
    {blx@dlist@entry@\the\c@refsection @\blx@refcontext@context}}
\let\cbx@sortlist\@empty
\makeatother

\addbibresource{biblatex-examples.bib}
\renewcommand*{\thefootnote}{\fnsymbol{footnote}}
\begin{document}
\null\vfill\noindent
New citation.\sfcite{companion}
New and recurrent citations.\sfcite{kant:ku,companion}
Vanilla footnote with citation.\footnote{Following \textcite{companion}...}
\clearpage
\null\vfill\noindent
New citation.\sfcite{ctan}
Recurrent citations from previous and current pages.\sfcite{companion,ctan}
\clearpage
\printbibliography
\end{document}

Here are the citations from the first page:

enter image description here

And the second:

enter image description here

Printing of citation footnotes is deferred to the last inline citation, list of shorthands entry or bibliography item on the current page. This might pose a limitation if the document also contains regular footnotes, but can likely be resolved by using a package like manyfoot.

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