How to access class boolean macro from main .tex document

Question

I'm trying to access the boolean macro I defined with my class. Whenever I access the boolean within the class, it works fine. However, if try to access it from the main document (using the same code), I get an Undefined control sequence. \ifMY.

testclass.cls

%! Class = testclass
\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{testclass}[2023/11/29 Minimum Working Example Class]
\LoadClass[t,xcolor={x11names},aspectratio=169]{beamer}
\RequirePackage{kvoptions}
\SetupKeyvalOptions{family=MY,prefix=MY@}
\DeclareBoolOption{optA}
\ProcessKeyvalOptions*
\newcommand{\test}{\ifMY@optA
true
\else
false
\fi}

test.tex

% Preamble
\documentclass[optA=false]{testclass}
% Document
\begin{document}
\begin{frame}{Works fine.}
    \test
\end{frame}
\begin{frame}{Has an error.}
    \ifMY@optA
    true
    \else
    false
    \fi
\end{frame}
\end{document}

How can I use the if within the document, or would I have to create a command in the class, similar to \test?

Answer 1

@ are not allowed in the main document for the macro name. Take a look this post. To make it work, several options you can do.

1. Get rid of the @ sign in prefix.

2. Add \makeatletter and \makeatother before and after the frame env.

3. Copy the \ifMY@optA command to make a version without @.

I prefer the last option.

Here is the code for testclass.cls:

\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{testclass}[2023/11/29 Minimum Working Example Class]
\LoadClass[t,xcolor={x11names},aspectratio=169]{beamer}
\RequirePackage{kvoptions}
\SetupKeyvalOptions{family=MY,prefix=MY@}
\DeclareBoolOption{optA}
\ProcessKeyvalOptions*
\let\ifmyoptA\ifMY@optA
\newcommand{\test}{\ifMY@optA
true
\else
false
\fi}

Here is the code for main document:

% Preamble
\documentclass[optA=false]{testclass}
% Document
\begin{document}
\begin{frame}{Works fine.}
    \test
\end{frame}
\begin{frame}{Has an error.}
    \ifmyoptA
    true
    \else
    false
    \fi
\end{frame}
\end{document}