Bold names and year in bibliography, small caps for authors in citations

Question

I'm writing a thesis and I have to use a really weird citation style. I'm using biblatex with Biber, style authoryear

In \textcite{key} it is supposed to look like:

MEYER und SMITH (2016:27)

more than two authors:

WOLF et al. (2016:24)

normal \cite{key} should produce for more than two authors

(MEYER et al. 2016:27)

or for one or two

(MEYER und SMITH 2017:56)

Two authors with the same last name should get the first letter of their first name, like:

(MEYER, K. und MEYER, S., 2016:27)

(MEYER, A. 2015:45; MEYER, B. 2016:48)

• I do not know if only when both are cited together or even when the cites are independent - I'll post it as soon as I know.

In the bibliography there is something special, too.

article:

Meyer, A. C., Smith, A., Wolf, G. (2012): The impact of LaTeX. Journal of LaTeX 95, 5:2227-2247

book:

Meyer, A. C. (2012): [Title]. [Publisher], [City of Publisher], [edition]

chapter of a book:

Meyer, F. (2009): [chapter]. In: [editor] (2009)(Hrsg.): [Title]. [Publisher], [City of publisher], [edition]: 52-57

editor not in bold, but equal to author, edition like "1. Auflage"

These are the Problems I spotted so far - the dot or comma should not be a big deal, author and year in bold (at the bibliography) and Author in big letters (no small caps), city of publisher I have, so far, no idea how to do that. The problems with the dots and the other minor stuff I'm able to sort out, but with the bold and upper case I have no idea how to do that. Some hints would be great!

Thanks for your help!

An example:

\documentclass[12pt,titlepage]{scrartcl}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[
    backend=biber,
    style=authoryear,
    maxcitenames=2
]{biblatex}

\DefineBibliographyStrings{ngerman}{
    andothers = {{et\,al\adddot}}
}

%makes Small Caps for hole cite, not only for author name
\renewcommand*{\citesetup}{
    \sc
}

\addbibresource{bibtex/bib.bib}

\begin{document}

This \textcite[347\psq]{karg1969einfluss} or that \cite[347]{helmert2003n}


\printbibliography[title=Literaturverzeichnis]

\end{document}

@article{karg1969einfluss,
  title={Der Einflu{\ss} verschiedener Fruchtfolgen, insbesondere mit mehrj{\"a}hrigem Kleegras, auf sch{\"a}dliche und n{\"u}tzliche Mikroarthropoden im Boden},
  author={Karg, Wolfgang},
  journal={Archives of Phytopathology \& Plant Protection},
  volume={5},
  number={5},
  pages={347--371},
  year={1969},
  publisher={Taylor \& Francis}
}

@article{helmert2003n,
  title={N-Fl{\"u}sse in gemulchtem und geschnittenem Kleegras: Warum Kleegras-Brache im {\"O}kologischen Landbau (OL) die Ertr{\"a}ge der Fruchtfolge nicht erh{\"o}ht},
  author={Helmert, Martin and Heuwinkel, Hauke and Pommer, G{\"u}nther and Gutser, Reinhold and Schmidhalter, Urs},
  journal={DBG-Mitteilungen},
  volume={102},
  number={1},
  pages={347--348},
  year={2003}
}

Answer 1

The following should get you started. It probably doesn't cover everything you asked for, but the base style should be there.

The code below uses the style ext-authoryear form my biblatex-ext bundle because it has a few more customisation options than the standard authoryear style.

The most interesting bit for me was the bold name and year at the beginning of the entry. Unfortunately, the only way I found to do that properly requires you to redefine some longish macros. Furthermore, we use the punctfont option, which makes sure that punctuation inherits the format of the previous field.

Most of the other details are standard things that have been asked elsewhere on this site, so I will not explain things in more detail here. If you look up the involved commands in the biblatex documentation and the biblatex-ext documentation, it should be possible to find out what each line of code does. If you have a question about anything, feel free to leave a comment.

\documentclass[12pt,titlepage]{scrartcl}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage{csquotes}

\usepackage[
  backend=biber,
  style=ext-authoryear,
  maxcitenames=2, maxbibnames=999,
  giveninits=true,
  uniquename=init, uniquelist=false,
  articlein=false, innamebeforetitle=true,
  punctfont=true,
]{biblatex}

\DefineBibliographyStrings{ngerman}{
  andothers = {et\addabbrvspace al\adddot}
}

\renewcommand*{\mkbibnamefamily}{\textsc}
\AtBeginBibliography{%
  \renewcommand*{\mkbibnamefamily}[1]{#1}}

\DeclareNameFormat{labelname}{%
  \ifnum\value{uniquename}=0\relax
    \usebibmacro{name:family}
      {\namepartfamily}
      {\namepartgiven}
      {\namepartprefix}
      {\namepartsuffix}%
  \else
    \usebibmacro{name:family-given}
      {\namepartfamily}
      {\namepartgiveni}
      {\namepartprefix}
      {\namepartsuffixi}%
  \fi
  \usebibmacro{name:andothers}}

\DeclareNameAlias{default}{family-given}
\DeclareNameAlias{sortname}{default}

\renewbibmacro*{author}{%
  \printtext[bold]{%
    \ifboolexpr{
      test \ifuseauthor
      and
      not test {\ifnameundef{author}}
    }
      {\usebibmacro{bbx:dashcheck}
         {\bibnamedash}
         {\usebibmacro{bbx:savehash}%
          \printnames{author}%
          \iffieldundef{authortype}
            {\setunit{\printdelim{nameyeardelim}}}
            {\setunit{\printdelim{authortypedelim}}}}%
       \iffieldundef{authortype}
         {}
         {\usebibmacro{authorstrg}%
          \setunit{\printdelim{nameyeardelim}}}}%
      {\global\undef\bbx@lasthash
       \usebibmacro{labeltitle}%
       \setunit*{\printdelim{nonameyeardelim}}}%
    \usebibmacro{date+extradate}}}


\renewbibmacro*{bbx:editor}[1]{%
  \printtext[bold]{%
    \ifboolexpr{
      test \ifuseeditor
      and
      not test {\ifnameundef{editor}}
    }
      {\usebibmacro{bbx:dashcheck}
         {\bibnamedash}
         {\printnames{editor}%
          \setunit{\printdelim{editortypedelim}}%
          \usebibmacro{bbx:savehash}}%
       \usebibmacro{#1}%
       \clearname{editor}%
       \setunit{\printdelim{nameyeardelim}}}%
      {\global\undef\bbx@lasthash
       \usebibmacro{labeltitle}%
       \setunit*{\printdelim{nonameyeardelim}}}%
    \usebibmacro{date+extradate}}}

\renewbibmacro*{bbx:translator}[1]{%
  \printtext[bold]{%
    \ifboolexpr{
      test \ifusetranslator
      and
      not test {\ifnameundef{translator}}
    }
      {\usebibmacro{bbx:dashcheck}
         {\bibnamedash}
         {\printnames{translator}%
          \setunit{\printdelim{translatortypedelim}}%
          \usebibmacro{bbx:savehash}}%
       \usebibmacro{#1}%
       \clearname{translator}%
       \setunit{\printdelim{nameyeardelim}}}%
      {\global\undef\bbx@lasthash
       \usebibmacro{labeltitle}%
       \setunit*{\printdelim{nonameyeardelim}}}%
    \usebibmacro{date+extradate}}}

\DeclareDelimAlias*[bib]{finalnamedelim}{multinamedelim}


\DeclareNameWrapperFormat{sortname}{\mkbibbold{#1}}
\DeclareFieldFormat{biblabeldate}{\mkbibbold{\mkbibparens{#1}}}

\DeclareDelimFormat[bib]{nametitledelim}{\addcolon\space}

\renewcommand*{\volnumdelim}{\addcomma\space}

\DeclareFieldFormat{pages}{#1}

\renewcommand*{\bibpagespunct}{\addcolon\ifentrytype{article}{}{\space}}

\DeclareDelimFormat{postnotedelim}{\addcolon}
\DeclareFieldFormat{postnote}{\mknormrange{#1}}

\begin{filecontents}{\jobname.bib}
@article{karg1969einfluss,
  title   = {Der Einfluß verschiedener Fruchtfolgen,
             insbesondere mit mehrjährigem Kleegras,
             auf schädliche und nützliche Mikroarthropoden im Boden},
  author  = {Karg, Wolfgang},
  journal = {Archives of Phytopathology \& Plant Protection},
  volume  = {5},
  number  = {5},
  pages   = {347-371},
  year    = {1969},
}
@article{helmert2003n,
  title   = {N-Flüsse in gemulchtem und geschnittenem Kleegras:
             Warum Kleegras-Brache im Ökologischen Landbau (OL)
             die Erträge der Fruchtfolge nicht erhöht},
  author  = {Helmert, Martin and Heuwinkel, Hauke and Pommer, Günther
             and Gutser, Reinhold and Schmidhalter, Urs},
  journal = {DBG-Mitteilungen},
  volume  = {102},
  number  = {1},
  pages   = {347-348},
  year    = {2003},
}
\end{filecontents}
\addbibresource{\jobname.bib}

\begin{document}
This \textcite[347\psq]{karg1969einfluss}
or that \autocite[347]{helmert2003n}

\printbibliography[title=Literaturverzeichnis]
\end{document}

For any additional changes I'd encourage you to ask new, separate questions. The general idea on this site is to ask about one specific thing per question and not about one big and complex thing like "how do I get this bibliography style". That way answers are more useful for the general public and more to the point.