Tikz, text along path, accents

Question

In a M(not-)WE as below, is there a way to insert \'{e}, \'{a} and similar commands? The simple minded solution, just insert them, does not seem to work.

EDIT: If I compile it, I get a ! Illegal parameter number in definition of \iterate.. If I try to > r, compilation halts anyway. If I embrace accents commands in their own pair of braces, I get the same error, but >r takes up compilation to the output. If I use the key raise too, it runs fine.

\documentclass {beamer}
\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing,intersections}
\usetikzlibrary{calc, arrows, decorations.markings, decorations.text, arrows.meta}

\begin{document}
    \begin{frame}

    \begin{tikzpicture}
    \path (0 :4cm) node (x) {AAAAAA} 
    (180:4cm) node (y) {BBBBB};
    \def\myshift#1{\raisebox{1ex}}
    \draw [-{Stealth[length=3mm, width=2mm]}, thick, postaction={decorate, decoration={text along path, text align=center, text={|\sffamily\myshift| \`{e}, \`{a}, \`{u}, \`{i}, \`{o} }}}] (y) to [bend left=45]  (x);
    \def\myshift#1{\raisebox{-2.5ex}}
    \draw [-{Stealth[length=3mm, width=2mm]}, thick, postaction={decorate, decoration={text along path, reverse path, text align=center, text={|\sffamily\myshift|Ok \textbf{Pk}, \textcolor{red}{Ok}  } }}] (x) to [bend left=45] (y);
\end{tikzpicture}

\end{frame}
\end{document}

Answer 1

There are several problems:

1. you're missing a closing brace after text={...` for the top arrow;

2. problematic combinations should be braced;

3. you define \myshift to take an argument, but you shouldn't.

Besides, using \myshift is not the best approach anyway, as TikZ has the key raise for the same purpose.

\documentclass{beamer}
\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing,intersections}
\usetikzlibrary{calc, arrows, decorations.markings, decorations.text, arrows.meta}

\begin{document}

\begin{frame}

\begin{tikzpicture}
  \path (0:4cm) node (x) {AAAAAA} (180:4cm) node (y) {BBBBB};
  \draw[
    -{Stealth[length=3mm, width=2mm]},
    thick,
    postaction={
      decorate,
      decoration={
        text along path,
        raise=1ex,
        text align=center,
        text={|\sffamily|{\`{e}}, {\`{a}}, {\`{u}}, {\`{i}}, {\`{o}}},
      }
    }
  ] (y) to [bend left=45]  (x);
  \draw[
    -{Stealth[length=3mm, width=2mm]},
    thick,
    postaction={
      decorate,
      decoration={
        text along path,
        reverse path,
        raise=-2.5ex,
        text align=center,
        text={|\sffamily|Ok {\textbf{Pk}}, {\textcolor{red}{Ok}}}
      }
    }
  ] (x) to [bend left=45] (y);
\end{tikzpicture}

\end{frame}

\end{document}