[Tex/LaTex] How to add square brackets for the authoryear biblatex bibliography style

biblatexbrackets

Due to some university requirements, I redefined the biblatex citesytle authoryear to use square brackets instead of round parentheses. Now I am trying to achieve the same for the bibstyle.

My approach to this is to redefine the original style file, authoryear.bbx. This worked fine for the citestyle, which I am not repeating here because the styles work very differently.

Reading the manual [ 1 ], I found out that (round) parentheses are put around fields using the command \printtext[parens]{....}. Here, the field parens is defined as \DeclareFieldFormat{parens}{\mkbibparens{#1}} [1, p. 268]. In analogy to this, I tried to define a new field bracks like so: \DeclareFieldFormat{bracks}{\mkbibbrackets{#1}} (see [1, p. 250]).

My approach is now to replace the field parens by bracks everywhere in the associated style file, see the MWE below:

\documentclass{scrartcl}

\usepackage{filecontents}

\begin{filecontents*}{authoryearbrak.bbx}
\ProvidesFile{authoryearbrak.bbx}
[\abx@bbxid]

% authoryear styles are special in the following way:

% The citation labels are "labelname (labelyear)" and since citation
% labels are the keys into the references section, the fact that the
% citation uses labelyear means that the references must also. This
% means we use a special \printdate[extra]label macro to generate the
% references section main date for an entry. Otherwise, if labeldate selects
% anything other than DATE (or equivalently, YEAR/MONTH), then the
% citation won't match the reference.

% Addition!
% Add new field for square brackets
\DeclareFieldFormat{bracks}{\mkbibbrackets{#1}}

\RequireBibliographyStyle{standard}

\DeclareBibliographyOption{dashed}[true]{%
  \ifstrequal{#1}{true}
    {\ExecuteBibliographyOptions{pagetracker}%
     \renewbibmacro*{bbx:savehash}{\savefield{fullhash}{\bbx@lasthash}}}
    {\renewbibmacro*{bbx:savehash}{}}}

\DeclareBibliographyOption{mergedate}[true]{%
  \ifcsdef{bbx@opt@mergedate@#1}
    {\csuse{bbx@opt@mergedate@#1}}
    {\PackageError{biblatex}
       {Invalid option 'mergedate=#1'}
       {Valid values are 'maximum', 'compact', 'basic', 'minimum',\MessageBreak
        'true' (=compact), and 'false'.}}}

\providebibmacro*{date+extrayear}{}

\def\bbx@opt@mergedate@true{\bbx@opt@mergedate@compact}

\def\bbx@opt@mergedate@maximum{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[bracks]{%
         \printfield{issue}%
     \setunit*{\addspace}%
     \printdateextralabel}}}%
  \renewbibmacro*{date}{}%
  \renewbibmacro*{issue+date}{}%
}

\def\bbx@opt@mergedate@compact{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[s]{\printdateextralabel}}}%
  \renewbibmacro*{date}{}%
  \renewbibmacro*{issue+date}{%
    \iffieldundef{issue}
      {}
      {\printtext[bracks]{\printfield{issue}}}%
    \newunit}%
}

\def\bbx@opt@mergedate@basic{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[bracks]{%
     \printfield{labelyear}%
     \printfield{extrayear}}}}%
  \renewbibmacro*{date}{%
    \iffieldundef{month}
      {}
      {\printdate}}%
  \renewbibmacro*{issue+date}{%
    \ifboolexpr{
      test {\iffieldundef{issue}}
      and
      test {\iffieldundef{month}}
    }
      {}
      {\printtext[bracks]{%
     \printfield{issue}%
     \setunit*{\addspace}%
     \printdate}}%
    \newunit}%
}

\def\bbx@opt@mergedate@minimum{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[bracks]{%
     \printfield{labelyear}%
     \printfield{extrayear}}}}%
  \renewbibmacro*{date}{%
    \ifboolexpr{
      test {\iffieldundef{month}}
      and
      test {\iffieldundef{extrayear}}
    }
      {}
      {\printdate}}%
  \renewbibmacro*{issue+date}{%
    \ifboolexpr{
      test {\iffieldundef{issue}}
      and
      test {\iffieldundef{month}}
      and
      test {\iffieldundef{extrayear}}
    }
      {}
      {\printtext[bracks]{%
     \printfield{issue}%
     \setunit*{\addspace}%
     \printdate}}%
    \newunit}%
}

\def\bbx@opt@mergedate@false{%
  \renewbibmacro*{date+extrayear}{%
    \iffieldundef{labelyear}
      {}
      {\printtext[bracks]{%
     \printfield{labelyear}%
     \printfield{extrayear}}}}%
  \renewbibmacro*{date}{\printdate}%
  \renewbibmacro*{issue+date}{%
    \printtext[bracks]{%
      \printfield{issue}%
      \setunit*{\addspace}%
      \printdate}%
    \newunit}%
}

\ExecuteBibliographyOptions{labeldate,sorting=nyt,pagetracker,mergedate}

\DeclareFieldFormat{shorthandwidth}{#1}
\setlength{\bibitemsep}{0pt}

\DeclareNameAlias{author}{sortname}
\DeclareNameAlias{editor}{sortname}
\DeclareNameAlias{translator}{sortname}

\defbibenvironment{bibliography}
  {\list
     {}
     {\setlength{\leftmargin}{\bibhang}%
      \setlength{\itemindent}{-\leftmargin}%
      \setlength{\itemsep}{\bibitemsep}%
      \setlength{\parsep}{\bibparsep}}}
  {\endlist}
  {\item}

\defbibenvironment{shorthands}
  {\list
     {\printfield[shorthandwidth]{shorthand}}
     {\setlength{\labelwidth}{\shorthandwidth}%
      \setlength{\leftmargin}{\labelwidth}%
      \setlength{\labelsep}{\biblabelsep}%
      \addtolength{\leftmargin}{\labelsep}%
      \setlength{\itemsep}{\bibitemsep}%
      \setlength{\parsep}{\bibparsep}%
      \renewcommand*{\makelabel}[1]{##1\hss}}}
  {\endlist}
  {\item}

\InitializeBibliographyStyle{%
  \global\undef\bbx@lasthash}

\newbibmacro*{bbx:savehash}{%
  \savefield{fullhash}{\bbx@lasthash}}

\newbool{bbx@inset}
\DeclareBibliographyDriver{set}{%
  \booltrue{bbx@inset}%
  \entryset{}{}%
  \newunit\newblock
  \usebibmacro{setpageref}%
  \finentry}

\renewbibmacro*{author}{%
  \ifboolexpr{
    test \ifuseauthor
    and
    not test {\ifnameundef{author}}
  }
    {\usebibmacro{bbx:dashcheck}
       {\bibnamedash}
       {\usebibmacro{bbx:savehash}%
        \printnames{author}%
    \iffieldundef{authortype}
      {\setunit{\addspace}}
      {\setunit{\addcomma\space}}}%
     \iffieldundef{authortype}
       {}
       {\usebibmacro{authorstrg}%
    \setunit{\addspace}}}%
    {\global\undef\bbx@lasthash
     \usebibmacro{labeltitle}%
     \setunit*{\addspace}}%
  \usebibmacro{date+extrayear}}

\renewbibmacro*{editor}{%
  \usebibmacro{bbx:editor}{editorstrg}}
\renewbibmacro*{editor+others}{%
  \usebibmacro{bbx:editor}{editor+othersstrg}}
\newbibmacro*{bbx:editor}[1]{%
  \ifboolexpr{
    test \ifuseeditor
    and
    not test {\ifnameundef{editor}}
  }
    {\usebibmacro{bbx:dashcheck}
       {\bibnamedash}
       {\printnames{editor}%
    \setunit{\addcomma\space}%
    \usebibmacro{bbx:savehash}}%
     \usebibmacro{#1}%
     \clearname{editor}%
     \setunit{\addspace}}%
    {\global\undef\bbx@lasthash
     \usebibmacro{labeltitle}%
     \setunit*{\addspace}}%
  \usebibmacro{date+extrayear}}

\renewbibmacro*{translator}{%
  \usebibmacro{bbx:translator}{translatorstrg}}
\renewbibmacro*{translator+others}{%
  \usebibmacro{bbx:translator}{translator+othersstrg}}
\newbibmacro*{bbx:translator}[1]{%
  \ifboolexpr{
    test \ifusetranslator
    and
    not test {\ifnameundef{translator}}
  }
    {\usebibmacro{bbx:dashcheck}
       {\bibnamedash}
       {\printnames{translator}%
    \setunit{\addcomma\space}%
    \usebibmacro{bbx:savehash}}%
     \usebibmacro{translator+othersstrg}%
     \clearname{translator}%
     \setunit{\addspace}}%
    {\global\undef\bbx@lasthash
     \usebibmacro{labeltitle}%
     \setunit*{\addspace}}%
  \usebibmacro{date+extrayear}}

\newbibmacro*{bbx:dashcheck}[2]{%
  \ifboolexpr{
    test {\iffieldequals{fullhash}{\bbx@lasthash}}
    and
    not test \iffirstonpage
    and
    (
       not bool {bbx@inset}
       or
       test {\iffieldequalstr{entrysetcount}{1}}
    )
  }
    {#1}
    {#2}}

\newbibmacro*{labeltitle}{%
  \iffieldundef{label}
    {\iffieldundef{shorttitle}
       {\printfield{title}%
        \clearfield{title}}
       {\printfield[title]{shorttitle}}}
    {\printfield{label}}}

\endinput
\end{filecontents*}

\begin{filecontents*}{bibliography.bib}
@BOOK{Cornelisse1979,
  author = {Cornelisse, J. W. and Schöyer, H. Ferry R. and Wakker, Karel F.},
  title = {Rocket Propulsion and Spaceflight Dynamics},
  year = {1979},
  publisher = {Pitman},
}
\end{filecontents*}

\usepackage[bibstyle=authoryearbrak, citestyle=authoryear,%
    backend=biber,]{biblatex} 

\addbibresource{bibliography.bib}

\begin{document}

\autocite{Cornelisse1979}

\printbibliography

\end{document}

Sadly, this does not work, as the following screenshot demonstrates:

The brackets are missing around the year [1979].

The brackets are missing altogether. It should say [1979]. For the default authoryear style it would say (1979).

Where is this going wrong? How can I fix this, in order to get square brackets instead of round parentheses around the year?

[ 1 ] — http://archive.cs.uu.nl/mirror/CTAN/macros/latex/contrib/biblatex/doc/biblatex.pdf


Rationale for square brackets: Parenthesis typically indicate small additions or afterthoughts. Citations, however, are something entirely different, and thus deserve a special notation. This is also consistent with the pure numbering style that is sometimes used, e.g. [23] to indicate reference 23.

Best Answer

There is already a field format defined for square brackets - it is called brackets.

In authoryear styles, the year part of the label is created by the macro \printdateextralabel. In your authoryearbrak, you have have a spurious [s] format for \printdatextralabel (line 59). Replacing that with [brackets] yields

Cornelisse, J. W., H. Ferry R. Schoeyer, and Karel F. Wakker [1979]. Rocket Propulsion and Spaceflight Dynamics. Pitman.

Does this answer the question ?