Anbei sende ich euch meinen code. Bei mir läuft er, im Onlineeditor erscheint der Fehler: Package biblatex Error: Command '\cite' undefined. Ich hoffe ihr könnt mir trotzdem helfen. Vielen Dank schon einmal im Voraus.
\begin{filecontents*}{Manuskript.bib}
@commentary{CalliessR,
Address = {München},
Author = {Calliess, Christian and Ruffert, Matthias},
Booktitle = {EUV/AEUV Kommentar},
Date-Added = {2015-11-16 16:40:08 +0000},
Date-Modified = {2016-09-01 13:14:17 +0000},
Edition = {5},
Editor = {Calliess, Christian and Ruffert, Matthias},
Publisher = {C.H. Beck},
Title = {EUV/AEUV Kommentar},
Year = {2016}}
@incollection{Kokott,
Address = {Kehl},
Author = {Kokott, Juliane},
Booktitle = {Völkerrecht als Wertordnung -- Festschrift für Christian Tomuschat},
Date-Added = {2016-11-24 11:40:13 +0000},
Date-Modified = {2016-11-24 11:51:25 +0000},
Editor = {Dupuy, Pierre-Marie and Fassbender, Bardo and Shaw, Malcom and Sommermann, Karl-Peter},
Pages = {207-226},
Publisher = {N.P. Engel Verlag},
Title = {Die Freizügigkeit der Unionsbürger als neue Grundfreiheit},
Year = {2006}}
\end{filecontents*}
\begin{filecontents}{Test.bbx}
\ProvidesFile{Test.bbx}[2016/12/14 v0.1f biblatex bibliography style]
\RequireBibliographyStyle{authoryear}
\end{filecontents}
\begin{filecontents}{Test.cbx}
\ProvidesFile{Test.cbx}[2016/12/14 v0.1f biblatex citation style]
\RequireCitationStyle{authortitle-dw}%
%Fußnotenformat für Kommentare:
\DeclareNameFormat{family}{%
\usebibmacro{name:family}
{\namepartfamily}
{\namepartgiven}
{\namepartprefix}
{\namepartsuffix}%
\usebibmacro{name:andothers}}
\DeclareBibliographyDriver{cite:commentary}{%
\usebibmacro{in:}%
\iffieldundef{shorthand}%
{\printnames[family]{editor}}%
{\ifbool{cbx:shorthandibid}%
{\ifthenelse{\ifciteibid\AND\NOT\iffirstonpage}%
{\usebibmacro{cite:ibid}}%
{\usebibmacro{cite:shorthand}}}%
{\usebibmacro{cite:shorthand}}}%
\setunit{\addcomma\space}%
\printfield{title}}
% Kursive Schrift für Bearbeiter von Kommentaren
\DeclareFieldFormat[commentary]{prenote}{\mkbibemph{#1}\addcomma}%
% Shorthand ersetzt bei Kommentaren nicht den Autor, sondern
% den Herausgeber
\renewbibmacro*{cite:normal}{%
\iffieldequalstr{entrytype}{commentary}{% <---
{\ifthenelse{\ifciteibid\AND\NOT\iffirstonpage}
{\usebibmacro{cite:ibid}}
{\usedriver{}{cite:commentary}}}}%
{\iffieldundef{shorthand}%
{\ifthenelse{\ifciteibid\AND\NOT\iffirstonpage}
{\usebibmacro{cite:ibid}}
{\ifthenelse{\ifciteidem\AND\NOT\boolean{cbx:noidem}%
\AND\NOT\iffirstonpage}%
{\usebibmacro{cite:idem}%
\usebibmacro{cite:title}%
\usebibmacro{cite:save}}
{\ifnameundef{labelname}
{}
{\usebibmacro{cite:name}}%
\usebibmacro{cite:title}}%
\ifbool{cbx:omiteditor}
{}
{\ifnameundef{labelname}
{\newunit
\usebibmacro{cite:byeditor}}
{}}%
\usebibmacro{cite:save}}}
{\ifbool{cbx:shorthandibid}%
{\ifthenelse{\ifciteibid\AND\NOT\iffirstonpage}%
{\usebibmacro{cite:ibid}}
{\usebibmacro{cite:shorthand}}}%
{\usebibmacro{cite:shorthand}}}%
}%
}%
% Fußnotenformat für Festschriften:
\DeclareBibliographyDriver{cite:incollection}{%
\usebibmacro{in:}%
{%
\iffieldundef{shorttitle}%
{\printfield{booktitle}}%
{\printfield{shorttitle}}%
}%
\iffieldundef{postnote}%
{\addcomma\space%
\printfield{pages}}%
{}%
}%
\end{filecontents}
\documentclass[oneside]{scrbook}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{setspace}
\usepackage{alnumsec}
\surroundarabic[(][)]{}{.}
\otherseparators{5}
\usepackage{geometry}
\geometry{a4paper,includehead, includefoot, left=20mm,right=20mm,top=20mm,bottom=10mm}
\usepackage[babel, german=quotes]{csquotes}
\usepackage[bibstyle=Test,citestyle=Test]{biblatex}
\bibliography{Manuskript}
\begin{document}
123\footcite[Vgl.][S. 2]{Kokott}
123\footcite[Brechmann][Art. 18 AEUV, Rn. 12]{CalliessR}
\printbibliography
\end{document}