biblatex: Setting maxnames on individual entries

Question

I'm using biblatex (with biber as backend). I use the global maxnames option to shorten author lists (with "et al."). However, I would like to create some exceptions to this rule for some specific entries.

I was hoping I could use the options entry field (for per-entry options).

For example, I would use the following global setting:

\usepackage[bibstyle=numeric-comp,citestyle=numeric-comp,backend=biber,maxnames=3]{biblatex}

I would then override the maxnames setting for some individual items, for example to allow a longer authors list, like so:

@INPROCEEDINGS{Vallejos2009b,
  author = {John Doe and Pete Peters and Jane Jones and John Johnson and Alison Anderson},
  title = {Some Title},
  booktitle = {...},
  year = {2009},
  options = {maxnames=5}
}

Unfortunately this does not work because maxnames is not supported as an entry-level option. At least in the current biblatex version.

Does anyone have an idea how I could do something like that?

PS: I use numeric citation style so my question only concerns the abbreviation of author lists in the bibliography itself.

Answer 1

You can't reliably do this yourself by either bib file keywords or style edits because maxnames (and maxbibnames, maxalphanames) is used internally by biber to do all sorts of things when generating the .bbl. So if it's not supported in biber as a per-entry option, entry information will potentially be wrong/inconsistent like labels, hashes and uniquename/uniquelist settings.

We have had a look at this and the functionality will be implemented in the next biber and biblatex versions, probably 0.9.6/1.7. You will be able to set:

maxnames/minnames maxcitenames/mincitenames maxbibnames/minbibnames maxalphanames/minalphanames maxitems/minitems

on a per-type and per-entry basis.

Just to confirm that this is now implemented in biber 0.9.6/biblatex 1.7 which were released a couple of days ago.

Answer 2

The solution is a HACK. See the legitimate answer of PLK.

You must modify each bibitem. I would to this by setting a special keyword to the relevant bib entry. At the beginning of the bibitem you can test whether the key is set or not. If the key is set you can change the counter maxnames.

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@INPROCEEDINGS{Vallejos2009b,
  author = {John Doe and Pete Peters and Jane Jones and John Johnson and Alison Anderson},
  title = {Some Title},
  booktitle = {...},
  year = {2009},
  keywords={increasemaxnames},
}

@book{test,
author="John Smith and John Doe and Pete Peters and Jane Jones and John Johnson",
title="TITLE",
year=2009,
publisher="PUP",
}
\end{filecontents}
\documentclass{article}
\usepackage[bibstyle=numeric-comp,citestyle=numeric-comp,backend=biber,maxnames=3]{biblatex}
\bibliography{\jobname.bib}
\AtEveryBibitem{%
\ifkeyword{increasemaxnames}%
   {\setcounter{maxnames}{5}}
   {\setcounter{maxnames}{3}}
}

\begin{document}
\cite{Vallejos2009b} \cite{test}
\printbibliography
\end{document}

EDIT:

Audrey wishes I method without editing the bib file. This is possible with a comparison of the entrykey. I build a command named \individualentry. The command needs a comma separate list of entrykeys. If the entrykey doesn't exist it will works too ;-)

Here the definition of the command:

\newrobustcmd*\individualentry[1]{%
  \def\tempa{}%
  \def\tempb{ ( test {\ifstrequal{2}{1}} ) }%
  \forcsvlist{\listeadd\tempa}{#1}
  \def\do##1{%
     \gappto\tempb{ or (test  {\iffieldequalstr{entrykey}{##1}}) }
  }%
  \dolistloop{\tempa}%
  \AtEveryBibitem{
    \expandafter\ifboolexpr\expandafter{\tempb}%
            {\setcounter{maxnames}{5}}%
            {\setcounter{maxnames}{3}}
  }
}

It is important that the command is used in the preamble!

Here the whole example:

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@INPROCEEDINGS{Vallejos2009b,
  author = {John Doe and Pete Peters and Jane Jones and John Johnson and Alison Anderson},
  title = {Some Title},
  booktitle = {...},
  year = {2009},
  keywords={increasemaxnames},
}

@book{test,
author="John Smith and John Doe and Pete Peters and Jane Jones and John Johnson",
title="TITLE",
year=2009,
publisher="PUP",
}
\end{filecontents}
\documentclass{article}
\usepackage[bibstyle=numeric-comp,citestyle=numeric-comp,backend=biber,maxnames=3]{biblatex}
\bibliography{\jobname.bib}
\newrobustcmd*\individualentry[1]{%
  \def\tempa{}%
  \def\tempb{ ( test {\ifstrequal{2}{1}} ) }%
  \forcsvlist{\listeadd\tempa}{#1}%
  \def\do##1{%
     \gappto\tempb{ or (test  {\iffieldequalstr{entrykey}{##1}}) }%
  }%
  \dolistloop{\tempa}%
  \AtEveryBibitem{%
    \expandafter\ifboolexpr\expandafter{\tempb}%
            {\setcounter{maxnames}{5}}%
            {\setcounter{maxnames}{3}}%
  }%%
  \AtEveryCitekey{%
     \expandafter\ifboolexpr\expandafter{\tempb}%
            {\setcounter{maxnames}{5}}%
            {\setcounter{maxnames}{3}}%
  }%
}
%\individualentry{foo,Vallejos2009b,test}
\individualentry{foo,Vallejos2009b}
\begin{document}
\cite{Vallejos2009b} \cite{test} 

\fullcite{Vallejos2009b}

 \fullcite{test} 

\printbibliography
\end{document}