Anwenden von pgfkeys in einem xparse-Befehl für referenzierte und personalisierte tags und labels

\documentclass[12pt]{scrreprt}

\usepackage[]{amsmath}

\usepackage{xparse} % lädt auch `expl3`

\makeatletter
\ExplSyntaxOn
\keys_define:nn { cis / tagx }
  {
    ,label .tl_set:N = \l__cis_tagx_label_tl
    ,name  .tl_set:N = \l__cis_tagx_name_tl
  }
\NewDocumentCommand \tagx { O{} }
  {
    \group_begin:
    \keys_set:nn { cis / tagx } { #1 }
    \tl_if_empty:NTF \l__cis_tagx_name_tl
      {
        \refstepcounter{equation}
        ( \theequation )
        \tl_if_empty:NF \l__cis_tagx_label_tl
          { \exp_args:NV \label \l__cis_tagx_label_tl }
      }
      {
        ( \l__cis_tagx_name_tl )
        \tl_if_empty:NF \l__cis_tagx_label_tl
          {
            \tl_set_eq:NN \@currentlabel \l__cis_tagx_name_tl
            \exp_args:NV \label \l__cis_tagx_label_tl
          }
      }
    \group_end:
  }
\ExplSyntaxOff
\makeatother

\begin{document}
\chapter{First Chapter}
An equation for counting: 
\begin{equation}
a+b=c\label{eq:bar1} 
\end{equation}

\bigskip
This is an inline-tag \tagx[label=foo1], it is also labeled \eqref{foo1}.

This is a personalized inline-tag \tagx[name=***,label=foo2], it is also labeled \eqref{foo2}.

\bigskip
This is an inline-tag \tagx, it is \emph{not} labeled.

This is a personalized inline-tag \tagx[name=***], it is \emph{not} labeled.

\bigskip
An another equation: 
\begin{equation}
1+1=2\label{eq:bar2} 
\end{equation}
\end{document}

\documentclass[12pt]{scrreprt}

\usepackage[]{amsmath}

\usepackage{xparse}
\usepackage{pgfkeys}

\makeatletter
\newcommand*\cistagx@label{}
\newcommand*\cistagx@name{}
\pgfkeys
  {%
    /cis/tagx/.cd
    ,label/.store in=\cistagx@label
    ,name/.store in=\cistagx@name
  }
\NewDocumentCommand \tagx { O{} }
  {%
    \begingroup
    \pgfkeys{/cis/tagx/.cd,#1}
    \ifx\cistagx@name\@empty
      \refstepcounter{equation}%
      (\theequation)%
      \ifx\cistagx@label\@empty
      \else
        \expandafter\label\expandafter{\cistagx@label}%
      \fi
    \else
      (\cistagx@name)%
      \ifx\cistagx@label\@empty
      \else
        \let\@currentlabel\cistagx@name
        \expandafter\label\expandafter{\cistagx@label}%
      \fi
    \fi
    \endgroup
  }
\makeatother

\begin{document}
\chapter{First Chapter}
An equation for counting: 
\begin{equation}
a+b=c\label{eq:bar1} 
\end{equation}

\bigskip
This is an inline-tag \tagx[label=foo1], it is also labeled \eqref{foo1}.

This is a personalized inline-tag \tagx[name=***,label=foo2], it is also labeled \eqref{foo2}.

\bigskip
This is an inline-tag \tagx, it is \emph{not} labeled.

This is a personalized inline-tag \tagx[name=***], it is \emph{not} labeled.

\bigskip
An another equation: 
\begin{equation}
1+1=2\label{eq:bar2} 
\end{equation}
\end{document}

\documentclass[12pt]{scrreprt}

\usepackage[]{amsmath}

\usepackage{xparse} % lädt auch `expl3`
\usepackage{pgfkeys}

\makeatletter
\ExplSyntaxOn
\tl_new:N \l__cis_tagx_label_tl
\tl_new:N \l__cis_tagx_name_tl
\pgfkeys
  {%
    /cis/tagx/.cd
    % we have to use `.store~in` instead of `.store in` as the spaces are
    % ignored in expl3 and `~` is a space here.
    ,label/.store~in=\l__cis_tagx_label_tl
    ,name/.store~in=\l__cis_tagx_name_tl
  }
\NewDocumentCommand \tagx { O{} }
  {%
    \group_begin:
    \pgfkeys{/cis/tagx/.cd,#1}
    \tl_if_empty:NTF \l__cis_tagx_name_tl
      {
        \refstepcounter{equation}
        ( \theequation )
        \tl_if_empty:NF \l__cis_tagx_label_tl
          { \exp_args:NV \label \l__cis_tagx_label_tl }
      }
      {
        ( \l__cis_tagx_name_tl )
        \tl_if_empty:NF \l__cis_tagx_label_tl
          {
            \tl_set:Nx \@currentlabel { \l__cis_tagx_name_tl }
            \exp_args:NV \label \l__cis_tagx_label_tl
          }
      }
    \group_end:
  }
\ExplSyntaxOff
\makeatother

\begin{document}
\chapter{First Chapter}
An equation for counting: 
\begin{equation}
a+b=c\label{eq:bar1} 
\end{equation}

\bigskip
This is an inline-tag \tagx[label=foo1], it is also labeled \eqref{foo1}.

This is a personalized inline-tag \tagx[name=***,label=foo2], it is also labeled \eqref{foo2}.

\bigskip
This is an inline-tag \tagx, it is \emph{not} labeled.

This is a personalized inline-tag \tagx[name=***], it is \emph{not} labeled.

\bigskip
An another equation: 
\begin{equation}
1+1=2\label{eq:bar2} 
\end{equation}
\end{document}