Tikz：创建节点后不触及路径就执行代码

Question

由于某些原因（为了让节点影响 tikzcd 中指向它的箭头的样式），我需要执行一段代码，该代码读取\tikzlastnode以获取 tikz(cd) 矩阵中当前位置的名称，但这仅在创建节点后定义。不幸的是，append after command需要一条路径（空路径显然不是有效输入），所以我需要创建一个假的空节点才能执行一条路径，这听起来真的很肮脏，我担心它可能会导致问题（添加空间，干扰下一个路径……）。我们可以在append after command完全不干扰路径的情况下运行（或等效）吗？

梅威瑟：

\documentclass{article}

\usepackage{tikz}
\usepackage{tikz-cd}

\begin{document}
\makeatletter
\begin{tikzcd}
  A \rar[/utils/exec={\message{BBBBB The message above (AAAA) should be equal to \tikzcd@ar@target}}, draw=\myfillcolor] & |[append after command={
    %%% Creating an empty node + /utils/exec sounds really dirty:
    node[/utils/exec={%
      \message{AAAA I need to have access to the name of the current node \tikzlastnode}%
      \gdef\myfillcolor{red}
    }%
    ] {}
  }
  ]| B
\end{tikzcd}
\end{document}

编辑

有人提议了\pgfextra ... \endpgfextra，而且可行！谢谢！

\documentclass{article}

\usepackage{tikz}
\usepackage{tikz-cd}

\begin{document}
\makeatletter
\begin{tikzcd}
  A \rar[/utils/exec={\message{BBBBB The message above (AAAA) should be equal to \tikzcd@ar@target}}, draw=\myfillcolor] & |[append after command={%
    \pgfextra% this syntax with \endpgfextra completely turns off the tikz syntax, that might be safer than \pgfextra{...}.
      \message{AAAA I need to have access to the name of the current node \tikzlastnode}%
      \gdef\myfillcolor{red}%
    \endpgfextra%
    }]| B
\end{tikzcd}
\end{document}