Biblatex: Selecting content depending on language

Question

I am using biblatex and would like to quote English and German works. When writing a document in German, this works nicely with the help of \DeclareLanguageMapping and hyphenation to specify if a reference should be quoted in either German or English style. However when writing the document I need the German bibliography entries to be changed - by adding the English translation in brackets in the corresponding fields (see attached MWE).

\documentclass{article}

\usepackage[english,american,ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{extarrows}
\usepackage{csquotes}
\usepackage[style=apa,
        bibencoding=utf8,
        sortcites=true,
        bibwarn=true,
        firstinits=true,
        isbn=false,
        dashed=false,
        maxbibnames=99,
        babel=other,
        backend=biber,
        hyperref=true]{biblatex}

\begin{filecontents}{myworks.bib}

@article{articleD,
  author  = {Peter Adams}, 
  title   = {Deutscher Titel},
  journal = {Journalname},
  year    = 1993,
  number  = 2,
  pages   = {201-213},
  month   = 7,
  note    = {Beispielkommentar}, 
  keyword = {D},
  volume  = 4
}

@article{articleE,
  author  = {Peter Adams}, 
  title   = {English Title},
  journal = {The name of the journal},
  year    = 1993,
  number  = 2,
  pages   = {201-213},
  month   = 7,
  note    = {An optional note}, 
  keyword = {E},
  volume  = 4
}

\end{filecontents}


\addbibresource{myworks.bib} 

\DeclareLanguageMapping{ngerman}{ngerman-apa}
\DeclareLanguageMapping{american}{american-apa}

\begin{document}
\nocite{*}
\selectlanguage{american}
\printbibliography[keyword=E]
\end{document}

One can achieve this by have a German and a English version of each bibliography entry (cf article, articleE), however this is not a nice solution. The best way for keeping the bibliography would be something like this (where translation is added after the title in brackets when the document is being written in English):

@article{article,
  author  = {Peter Adams}, 
  title   = {Deutscher Titel},
  titleE  = {English Title},
  journal = {Journalname},
  journalE= {The name of the journal},
  year    = 1993,
  number  = 2,
  pages   = {201-213},
  month   = 7,
  note    = {Beispielkommentar},
  noteE   = {An optional note}, 
  keyword = {E},
  volume  = 4
}

resulting in

Adams, P. (1993). Deutscher Titel [English Title]. Journalname/The name of the journal, 2, 201–213.

Does anyone know how to achieve this?

Cheers

Answer 1

As mentioned in the comments the experimental biblatex 4.0 knows "variant" of a field and together with biber 4.0 beta one can use them.

But it is not easy (and an complicated style like apa makes it even more difficult) and rather time consuming. One has to check a lot of macros to decide where and how one should inject the translation (and what to do if there is more than one variant, e.g. a translation and a transscription of some japanese title).

The following example shows an example code and its output with the experimental biblatex/biber:

\documentclass{article}

\usepackage[english,american,ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{extarrows}
\usepackage{csquotes}
\usepackage[style=apa,
        bibencoding=utf8,
        sortcites=true,
        bibwarn=true,
        firstinits=true,
        isbn=false,
        dashed=false,
        maxbibnames=99,
        babel=other,
        backend=biber,
        hyperref=true]{biblatex}


\addbibresource{test.bib}

\DeclareLanguageMapping{ngerman}{ngerman-apa}
\DeclareLanguageMapping{american}{american-apa}


\renewbibmacro*{journal}{%
  \iffieldundef{journaltitle}
    {}
    {\printtext[journaltitle]{%
       \printfield[titlecase]{journaltitle}%
       \setunit{\subtitlepunct}%
       \printfield[titlecase]{journalsubtitle}}}%
  \iffieldundef[form=translated,lang=english]{journaltitle}
    {}
    {%
     \setunit{/}%
     \printfield[][form=translated,lang=english]{journaltitle}%
    }%       
  }  

\renewbibmacro*{title}{%
  \ifthenelse{\iffieldundef{title}\AND\iffieldundef{subtitle}}
    {}
    {\iffieldundef{origtitle}
      {\printtext[title]{%
        \printfield[apacase]{title}%
        \setunit{\subtitlepunct}%
        \printfield[apacase]{subtitle}}
       \iffieldundef[form=translated,lang=english]{title}
       {}
       {%
       \setunit{}%
       \addspace
       \mkbibbrackets{\printfield[][form=translated,lang=english]{title}}%
       }%
      }
      {\printfield{origtitle}%
       \setunit{\addspace}%
       \printtext[brackets]{%
        \printfield[apacase]{title}%
        \setunit{\subtitlepunct}%
        \printfield[apacase]{subtitle}}}%
     \setunit{\addspace}%
     \printfield{titleaddon}%
     \iffieldequalstr{entrytype}{book}%
       {\setunit{\addspace}\usebibmacro{bookaddinfo}}%
       {}%
     \ifthenelse{%
       \ifnameundef{author}\AND%
       \(\ifnameundef{editor}\AND\NOT\boolean{bbx:editorinauthpos}\)\AND%
       \ifnameundef{producer}\AND%
       \ifnameundef{director}\AND%
       \ifnameundef{writer}}
        {\newunit\newblock
         \usebibmacro{labelyear+extrayear}}
        {}}}

\DeclareBibliographyDriver{article}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author/editor}%
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{title}%
  \newunit\newblock
  \usebibmacro{journal+issuetitle}%
  \setunit{\bibpagespunct}%
  \printfield{pages}%
  \newunit\newblock
  \printfield{note}%
  \iffieldundef[form=translated,lang=english]{note}
       {}
       {%
       \setunit{}%
       \addspace
       \mkbibparens{\printfield[][form=translated,lang=english]{note}}%
       }%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \printfield{addendum}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{apa:finpunct}%
  \usebibmacro{apa:pageref}%
  \usebibmacro{finentry}}           
\newbibmacro*{note+pages}{%
  \printfield{note}%

  \setunit{\bibpagespunct}%
  \printfield{pages}%
  \newunit}

\begin{document}
\cite{articletranslated}
\selectlanguage{american}
\printbibliography
\end{document}

test.bib:

@article{articletranslated,
  author  = {Peter Adams},
  title   = {Deutscher Titel},
  title_translated_english  = {English Title},
  journal = {Journalname},
  journaltitle_translated_english= {The name of the journal},
  year    = 1993,
  number  = 2,
  pages   = {201-213},
  month   = 7,
  note    = {Beispielkommentar},
  note_translated_english   = {An optional note},
  keyword = {E},
  volume  = 4
}

In my opinion quite often the invested time is not worth it.

A more simple approach would be to inject conditional text directly in the bib:

@article{articlewithengl,
  author  = {Peter Adams},
  title   = {Deutscher {Titel}\ifbool{useenglish}{\addspace\mkbibbrackets{English Title}}{}},
  journal = {Journalname\ifbool{useenglish}{/The name of the journal}{}},
  year    = 1993,
  number  = 2,
  pages   = {201-213},
  month   = 7,
  note    = {Beispielkommentar\ifbool{useenglish}{\addspace(An optional note)}{}},
  keyword = {E},
  volume  = 4
}

this can then be used simply with

\usepackage{etoolbox}
\newbool{useenglish}
\booltrue{useenglish} %or \boolfalse{useenglish}

Answer 2

The simplest solution (given that the apa biblatex style is used) is to store the translation in the titleaddon field (which is one of the standard biblatex fields).

Answer 3

Maybe these ideas will help you

% !TeX program = pdflatex 
\RequirePackage{filecontents}
\begin{filecontents*}{myworks.bib}
@article{article,
  author  = {Peter Adams}, 
  title   = {Deutscher Titel},
  titleE  = {English Title},
  journal = {Journalname},
  journalE= {The name of the journal},
  year    = 1993,
  number  = 2,
  pages   = {201-213},
  month   = 7,
  note    = {Beispielkommentar},
  noteE   = {An optional note}, 
  keywords = {E},
  volume  = 4
}
\end{filecontents*}

\documentclass{article}

\usepackage[english,american,ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{extarrows}
\usepackage{csquotes}
\usepackage[style=apa,
        bibencoding=utf8,
        sortcites=true,
        bibwarn=true,
        firstinits=true,
        isbn=false,
        dashed=false,
        maxbibnames=99,
        autolang=other,
        backend=biber,
        hyperref=true]{biblatex}

\addbibresource{myworks.bib} 

%%Thanks
%%http://tex.stackexchange.com/a/141831/79756
%%http://tex.stackexchange.com/a/226429/79756
%%for idea
\DeclareSourcemap{ 
    \maps{
        \map[overwrite]{
            \step[fieldsource=keywords,
            match={E},
            final]
            \step[fieldsource=titleE,]
            \step[fieldset=title, fieldvalue={~[}, append]
            \step[fieldset=title, origfieldval, append]
            \step[fieldset=title, fieldvalue={]}, append]
        }
        \map[overwrite]{
            \step[fieldsource=keywords,
            match={E},
            final]
            \step[fieldsource=journalE,]
            \step[fieldset=journal, fieldvalue={/}, append]
            \step[fieldset=journal, origfieldval, append]
        }
        \map[overwrite]{
            \step[fieldsource=keywords,
            match={E},
            final]
            \step[fieldsource=noteE,]
            \step[fieldset=note, fieldvalue={~[}, append]
            \step[fieldset=note, origfieldval, append]
            \step[fieldset=note, fieldvalue={]}, append]
        }
    }
}

\DeclareLanguageMapping{ngerman}{ngerman-apa}
\DeclareLanguageMapping{american}{american-apa}

\DeclareFieldFormat{apacase}{#1} %undo APA style sentence case correction for every field

\begin{document}
\nocite{*}
\selectlanguage{american}
\printbibliography[keyword=E]
\end{document}