Confine each exercise/question to one page using xsim

Question

I can do the following:

\begin{samepage}
\begin{exercise}
Long text question or maybe a table and some stuff etc.
\end{exercise}
\end{samepage}

But I would prefer to have this automated (since I feel like this would be possible).

I have tried declaring a new exercise environment. Trying to follow the \tcolorbox example in the xsim package manual but this does not work.

\documentclass[]{article}
    \usepackage{xsim}
    \usepackage{lipsum}
    
    \DeclareExerciseEnvironmentTemplate{customex}
      {%
        \begin{samepage}
        \subsection*
          {%
            {
            \XSIMmixedcase{\GetExerciseName}%
            \IfInsideSolutionTF
              {
                %\GetExerciseParameter{exercise-name}%
                ~\GetExerciseProperty{counter}.%
              }
              {%
                ~\GetExerciseProperty{counter}
                \GetExercisePropertyT{subtitle}
                  { {\normalfont\itshape\PropertyValue}}%
              }%
            }
          }
      }
      {\end{samepage}}
      
    \xsimsetup{exercise/template = customex}
    
    \begin{document}
        \begin{exercise}
            \lipsum[1-4]
        \end{exercise}
        
        \begin{exercise}
            \lipsum[1]  
        \end{exercise}
\end{document}

The result is Exercise 1 being broken across 2 pages, instead of the desired Exercise 1 on page 1 and Exercise 2 on page 2.

Answer 1

I get good results with

\xsimsetup{
    exercise/begin-hook  = \begin{samepage},
    exercise/end-hook = \end{samepage},
    solution/begin-hook  = \begin{samepage},
    solution/end-hook = \end{samepage},
}

The solution from @cgnieder with pre-hook/post-hook gave strange effects.

Answer 2

The easiest way without having to define any template would be

\BeforeBeginEnvironment{exercise}{%
  \begin{samepage}%
}
\AfterEndEnvironment{exercise}{%
  \end{samepage}%
}

Since \samepage “only” does some penalty settings this won't ensure that your exercises always are on the same page. (E.g., this doesn't help for your example).

If you want to be really sure that exercises stay on one page and if you also are sure that exercises never are longer than one page you can use a minipage:

\BeforeBeginEnvironment{exercise}{%
  \noindent\begin{minipage}{\linewidth}%
}
\AfterEndEnvironment{exercise}{%
  \end{minipage}\par
}

Probably even better with some vertical space added:

\documentclass{article}
\usepackage{xsim,lipsum}

\BeforeBeginEnvironment{exercise}{%
  \vspace{3.5ex plus 1ex minus .2ex}
  \noindent\begin{minipage}{\linewidth}%
}
\AfterEndEnvironment{exercise}{%
  \end{minipage}\par
}


\begin{document}

\begin{exercise}
  \lipsum[1-4]
\end{exercise}

\begin{exercise}
  \lipsum[1]
\end{exercise}

\begin{exercise}
  \lipsum[1]
\end{exercise}

\end{document}