Tikz and babel error

Question

This code works correctly:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{positioning,calc}
\begin{document}

\begin{tikzpicture}
  \tikzset{
    every picture/.prefix style={
      execute at begin picture=\shorthandoff{;}
    }
  }
  \def\names{{"1", "2"}}
  \foreach \i in {0,1} {%
    \ifnum\i=0\relax
      \node (\i) [draw] {\pgfmathparse{\names[\i]}\pgfmathresult};
    \else
      \pgfmathparse{int(\i-1)}
      \node (\i) [draw,right= 1cm of \pgfmathresult]
            {\pgfmathparse{\names[\i]}\pgfmathresult};
      \draw[dotted] ($(\pgfmathresult.south east) !.5! (\i.south west)$)
            -- +(0,1cm);
  \fi
}
\end{tikzpicture}
\end{document}

But when I add

\usepackage[utf8]{inputenc}
\usepackage[german]{babel}

to the preamble, it starts giving an error:

! Argument of \language@active@arg" has an extra }.
<inserted text> 
                \par 
l.25 }

the same for russian. It is somehow related to the quotes in the array:

\def\names{{"1", "2"}}

I tried the tricks, shown here for the french, but they don't work.

Answer 1

The trick for French disables the shorthand ;, which isn't used with German, where the shorthand to be disabled is ".

However, the \tikzset{every picture/...} command should be given outside the picture, or it won't have effect.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage{tikz}
\usetikzlibrary{positioning,calc}

\tikzset{
  every picture/.prefix style={
    execute at begin picture=\shorthandoff{"}
  }
}

\begin{document}

\begin{tikzpicture}
  \def\names{{"1", "2"}}
  \foreach \i in {0,1} {%
    \ifnum\i=0\relax
      \node (\i) [draw] {\pgfmathparse{\names[\i]}\pgfmathresult};
    \else
      \pgfmathparse{int(\i-1)}
      \node (\i) [draw,right= 1cm of \pgfmathresult]
            {\pgfmathparse{\names[\i]}\pgfmathresult};
      \draw[dotted] ($(\pgfmathresult.south east) !.5! (\i.south west)$)
            -- +(0,1cm);
  \fi
}
\end{tikzpicture}
\end{document}

Answer 2

\usetikzlibrary{babel} helps in this case to support active quotes:

\documentclass{article}
\usepackage[ngerman]{babel}
\usepackage{tikz}
\usetikzlibrary{babel,positioning,calc}
\begin{document}

\begin{tikzpicture}
  \tikzset{
    every picture/.prefix style={
      execute at begin picture=\shorthandoff{;}
    }
  }  
  \def\names{{"1", "2"}}
  \foreach \i in {0,1} {%
    \ifnum\i=0\relax
      \node (\i) [draw] {\pgfmathparse{\names[\i]}\pgfmathresult};
    \else
      \pgfmathparse{int(\i-1)}
      \node (\i) [draw,right= 1cm of \pgfmathresult]
            {\pgfmathparse{\names[\i]}\pgfmathresult};
      \draw[dotted] ($(\pgfmathresult.south east) !.5! (\i.south west)$)
            -- +(0,1cm);
  \fi
}
\end{tikzpicture}
\end{document}