(self-referential) Minipage of a page of the same document in XeLaTeX

Question

In a book, I want to include a small text at the end about the structure of the book. I want to include a figure of a page of the book itself for reference. The referenced page will be a different one than the one referencing it. This can be done by first compiling the pdf with a placeholder, extracting the page from the pdf and then including it as a minipage. Can this be done on one go, i.e. having the engine itself render the page in the minipage environment in one compilation run?

Answer 1

You can grab the page box before it is shipped out, for example

Here I used \AddToHook{shipout/before}, other hooks will give different effects, you may also want to try the new shipout hook to be added in the next release which is available currently (2022) using latex-dev

\documentclass[a4paper]{article}

\usepackage{graphicx}

\newbox\savedpage
\AddToHook{shipout/before}{%
  \ifnum\value{page}=1
   \global\setbox\savedpage\copy\ShipoutBox
  \fi}

\begin{document}

\section{aa}
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 


\begin{figure}[htp]
  \centering
  \includegraphics{example-image}
  \caption{abc}
\end{figure}

\section{aaa}
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 

\section{bbb}

xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 

\begin{figure}[htp]
  \centering
  \includegraphics{example-image-a}
  \caption{abc}
\end{figure}

xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 


\section{aa}
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 
xxx yyy xxx yyy xxx yyy xxx yyy 

\section{hmm}

And page 1 looked like

\begin{center}
  \fbox{\scalebox{0.25}{\makebox[\paperwidth][l]{%
    \hspace{1in}\usebox\savedpage}}}
\end{center}

\end{document}