Beamer \pause doesn't work with tabularray

[CarLaTeX]

In beamer, with the command \pause, you can show one table row at a time.
With tabular, it works perfectly but, with tlbr, it produces a strange output.
Compare the output of the following two frames.
See this post on TopAnswers TeX: https://topanswers.xyz/tex?q=2000.

\documentclass{beamer}
\usepackage{tabularray}

\begin{document}
\begin{frame}{With tabular works}
\begin{tabular}{cc}
    first & tabular\pause \\
    second & tabular \\ 
\end{tabular}
\end{frame}
\begin{frame}{With tblr doesn't work}
\begin{tblr}{cc}
    first & tblr\pause \\   
    second & tblr \\ 
\end{tblr}
\end{frame}
\end{document}

[davidcarlisle]

@CarLaTeX does that work with tabularx ? I'd be surprised if it does, these environments are doing multiple trial settings to determine the layout so making \pause work would be very non trivial. In simple cases it's probably possible to make it a no-op on all but the final run, but in general, interleaving beamer's overlays with multiple-pass layout is not easy. (@lvjr may accept the challenge, but if you posted the same thing to tabularx I'd say it was a documented feature)

[CarLaTeX]

@CarLaTeX does that work with tabularx ? I'd be surprised if it does, these environments are doing multiple trial settings to determine the layout so making \pause work would be very non trivial. In simple cases it's probably possible to make it a no-op on all but the final run, but in general, interleaving beamer's overlays with multiple-pass layout is not easy. (@lvjr may accept the challenge, but if you posted the same thing to tabularx I'd say it was a documented feature)

You're right, it does not work with tabularx, too.

[lvjr]

@davidcarlisle @CarLaTeX Actually it is complicated to catch \pause and change it to beamer overlays inside tabularray. Also it violates the principle of separating contents and styles. Therefore I won't do it (In fact, I ever opened issue #54 but closed it this year.)

User @registor of this package has done some tests on beamer overlays. It is not hard to do overlays with counter library and cmd option:

\documentclass{beamer}

\usepackage{tabularray}
\UseTblrLibrary{counter}

\begin{document}

\begin{frame}
\frametitle{Show a taularray row by row}
\begin{tblr}{colspec={lll},cells={cmd=\onslide<\arabic{rownum}->}}
 Alpha   & Beta  & Gamma  \\
 Epsilon & Zeta  & Eta    \\
 Iota    & Kappa & Lambda \\
\end{tblr}
\end{frame}

\begin{frame}
\frametitle{Show a tabularray column by column}
\begin{tblr}{colspec={lll},cells={cmd=\onslide<\arabic{colnum}->}}
 Alpha   & Beta  & Gamma  \\
 Epsilon & Zeta  & Eta    \\
 Iota    & Kappa & Lambda \\
\end{tblr}
\end{frame}

\begin{frame}
\frametitle{Show a tabularray cell by cell}
\begin{tblr}{colspec={lll},cells={cmd=\onslide<+->}}
 Alpha   & Beta  & Gamma  \\
 Epsilon & Zeta  & Eta    \\
 Iota    & Kappa & Lambda \\
\end{tblr}
\end{frame}

\end{document}

With this method, styles and contents of the tables are still well separated.

[CarLaTeX]

Thank you @lvjr for your alternative solutions!