newif for table does not work

Question

I create two different table contents and want to switch with a newif. \AAAfalse has no effect. What do I have to do?

\documentclass[a4paper, landscape]{article}
\usepackage{pgfplotstable}
\pgfplotsset{compat=newest}
\pgfplotstableset{string type, col sep=comma, header=false}

\newif\ifAAA
\AAAtrue

\ifAAA%================================
\pgfplotstableread[header=false]{
A, A
A, A
A, A
}\mytable
\def\mycolor{red}
\else%==================================
\pgfplotstableread[header=false]{
B, B
B, B
B, B
}\mytable
\def\mycolor{blue}
\fi%=====================================

\begin{document}
\section{\color{\mycolor} AAA true :)}
\pgfplotstabletypeset[]{\mytable}

\AAAfalse
\section{\color{\mycolor} AAA false :(}
\pgfplotstabletypeset[]{\mytable}
\end{document}

Answer 1

When you switch the \ifAAA you have already read the table; the macro \mytable has already been defined and it will not change. One possibility is to make the loading of the table dynamic (I had to change the termination because when into a macro, the newlines are changed to space tokens and that make the inline table unreadable):

\documentclass[a4paper, landscape]{article}
\usepackage{pgfplotstable}
\pgfplotsset{compat=newest}
\pgfplotstableset{string type, col sep=comma, header=false}

\newif\ifAAA
\AAAtrue

\def\loadtable{%
\ifAAA
\pgfplotstableread[header=false, row sep=crcr]{%
A, A \\
A, A \\
A, A \\
}\mytable
\def\mycolor{red}%
\else
\pgfplotstableread[header=false, row sep=crcr]{%
B, B \\
B, B \\
B, B \\
}\mytable
\def\mycolor{blue}%
\fi}

\begin{document}
\loadtable
\section{\color{\mycolor} AAA true :)}
\pgfplotstabletypeset[]{\mytable}

\AAAfalse
\loadtable
\section{\color{\mycolor} AAA false :(}
\pgfplotstabletypeset[]{\mytable}
\end{document}

Surely there are more elegant solutions, like defining two tables and switching on loading, but I got lost with \expandafters (I should seriously learn more LaTeX3).