Biblatex: Sorting citations in qualified citation list \parencites

Question

Following the answer https://tex.stackexchange.com/a/70183/56450, I was trying to get a correct sorting for keys in a \parencites command including pre- and post-notes. Is there an equivalent way to do it? All my attempts failed.

MWE:

%!TEX program = lualatex
\documentclass{scrbook}

\usepackage{fontspec}
\usepackage{polyglossia}
\setdefaultlanguage{german}
\usepackage{csquotes}

\usepackage[backend=biber%
           ,style=apa%
           ,maxcitenames=5%
           ,uniquename=full%
           ,sortcites%
           ]{biblatex}

\usepackage{filecontents}
\begin{filecontents}{refs.bib}
@incollection{Klieme,
    author = {Klieme, E.},
    title = {Titel},
    year = {2001},
}
@book{Clausen,
    author = {Clausen, M.},
    title = {Titel},
    year = {1998},
} 
\end{filecontents}
\addbibresource{refs.bib}

\begin{document}

\noindent
\verb+\parencite{Klieme,Clausen}+: \parencite{Klieme,Clausen}, correct sorting\\
\verb+\parencites{Klieme,Clausen}+: \parencites{Klieme,Clausen}, correct sorting\\
\verb+\parencites[vergl.][51]{Klieme}[114]{Clausen}+: \parencites[vergl.][51]{Klieme}[114]{Clausen}, wrong sorting

\end{document}

Answer 1

Audrey's great answer to Sorting citations using \cites command in biblatex only redefines the \cites command, but adding support for other \...cites is surprisingly (or perhaps not surprisingly) easy.

For \parencites we only need two additional lines

\DeclareMultiCiteCommand{\cbx@parencites}[\mkbibparens]{\parencite}{\multicitedelim}
\DeclareMultiCiteCommand{\parencites}[\cbx@cite@wrapper\cbx@parencites]{\cbx@cite}{}

for \textcites analogously

\DeclareMultiCiteCommand{\cbx@textcites}{\textcite}{\multicitedelim}
\DeclareMultiCiteCommand{\textcites}[\cbx@cite@wrapper\cbx@textcites]{\cbx@cite}{}

MWE

\documentclass{article}

\usepackage[backend=biber%
           ,style=authoryear%
           ,maxcitenames=5%
           ,uniquename=full%
           ,sortcites%
           ]{biblatex}

\makeatletter
\DeclareMultiCiteCommand{\cbx@parencites}[\mkbibparens]{\parencite}{\multicitedelim}
\DeclareMultiCiteCommand{\parencites}[\cbx@cite@wrapper\cbx@parencites]{\cbx@cite}{}

\DeclareMultiCiteCommand{\cbx@textcites}{\textcite}{\multicitedelim}
\DeclareMultiCiteCommand{\textcites}[\cbx@cite@wrapper\cbx@textcites]{\cbx@cite}{}

% original definition of \cites
\DeclareMultiCiteCommand{\cbx@cites}{\cite}{\multicitedelim}

% new definition
\DeclareMultiCiteCommand{\cites}[\cbx@cite@wrapper\cbx@cites]{\cbx@cite}{}

% first pass saves keys, prenotes, postnotes
\DeclareCiteCommand{\cbx@cite}
  {\csxdef{prenote:\thefield{entrykey}}{\thefield{prenote}}}
  {\listxadd\cbx@savekeys{\thefield{entrykey}}}
  {}
  {\csxdef{postnote:\thefield{entrykey}}{\thefield{postnote}}}

% second pass outputs sorted citation list
\newrobustcmd{\cbx@cite@wrapper}[2]{%
  \def\cbx@savekeys{}%
  \def\cbx@citecall{#1}%
  #2\cbx@sortkeysinit\cbx@citesort\cbx@citecall}

% internal list of saved keys => sorted argument list
\def\cbx@citesort{%
  \def\do##1{%
    \ifinlist{##1}{\cbx@savekeys}
      {\protected@xappto\cbx@citecall{%
         [\csuse{prenote:##1}][\csuse{postnote:##1}]{##1}}}
      {}}%
  \dolistloop{\cbx@sortkeys}}

% internal list of sorted entry keys
\def\cbx@sortkeysinit{%
  \ifcsundef{blx@dlist@entry@\the\c@refsection @\blx@refcontext@context}
    {}
    {\global\csletcs{cbx@sortkeys}{blx@dlist@entry@\the\c@refsection @\blx@refcontext@context}}}
\def\cbx@sortkeys{}
\makeatother

\addbibresource{biblatex-examples.bib}

\begin{document}
\noindent
\parencite{wilde,sigfridsson}\\
\parencites{wilde,sigfridsson}\\
\parencites[vergl.][51]{wilde}[114]{sigfridsson}\\
\parencites{knuth:ct:c}{knuth:ct:b}{knuth:ct:a}

\noindent
\cite{wilde,sigfridsson}\\
\cite{wilde,sigfridsson}\\
\cites[vergl.][51]{wilde}[114]{sigfridsson}\\
\cites{knuth:ct:c}{knuth:ct:b}{knuth:ct:a}

\noindent
\textcite{wilde,sigfridsson}\\
\textcite{wilde,sigfridsson}\\
\textcites[vergl.][51]{wilde}[114]{sigfridsson}\\
\textcites{knuth:ct:c}{knuth:ct:b}{knuth:ct:a}
\end{document}