Tcolorbox, exercises and the manyfoot package-2

Question

I use the tcolorbox package to produce exercises with solution. One can see that the usual footnotes are written inside the box, but when I have sometimes several footnotes, I use the manyfoot package to write these footnotes in "inlined" way, but I obtain an unwanted result. Only the marks of the footnotes are produced but not the footnotes themselves. The first question of my purpose was given here:

Tcolorbox, exercises and the manyfoot package

My question now is the following: In the box of the exercise, I produce its footnotes outside the box with the commands based on \footnotetextC where C is the suffix of my iniline item, given after the box of exercise, and one can see that it produces the wanted result for the question (see the .tex file used below and it's compilation). How can I obtain a similar way for the footnotes in the box of the solution (which can be based on commands like \footnotetextC), which produces the footnotes outside the box of the solution, like for the box of exercise.

Here's the .tex file used:

\documentclass{book}

\usepackage[most]{tcolorbox}
\tcbuselibrary{skins,breakable,xparse}

\usepackage{polyglossia}
\setmainlanguage{english}

\usepackage[para*]{manyfoot}
\DeclareNewFootnote[para]{C}
\makeatletter
\let\c@footnoteC\c@footnote
\makeatother

\renewcommand{\thefootnoteC}{\fnsymbol{footnote}}

\NewTColorBox[auto counter,number within=chapter]{exercise}{+O{}}{%
enhanced,colframe=green!20!black,colback=yellow!10!white,coltitle=green!40!black,
fonttitle=\bfseries,
underlay={\begin{tcbclipinterior}
\shade[inner color=green!80!yellow,outer color=yellow!10!white]
(interior.north west) circle (2cm);
\draw[help lines,step=5mm,yellow!80!black,shift={(interior.north west)}]
(interior.south west) grid (interior.north east);
\end{tcbclipinterior}},
title={Exercise~ \thetcbcounter:},
label={exercise@\thetcbcounter},
attach title to upper=\quad,
after upper={\par\hfill\textcolor{green!40!black}%
{\itshape Solution on page~\pageref{solution@\thetcbcounter}}},
lowerbox=ignored,
savelowerto=solutions/exercise-\thetcbcounter.tex,
record={\string\solution{\thetcbcounter}{solutions/exercise-\thetcbcounter.tex}},
#1
}
\NewTotalTColorBox{\solution}{mm}{%
enhanced,colframe=red!20!black,colback=yellow!10!white,coltitle=red!40!black,
fonttitle=\bfseries,
underlay={\begin{tcbclipinterior}
\shade[inner color=red!50!yellow,outer color=yellow!10!white]
(interior.north west) circle (2cm);
\draw[help lines,step=5mm,yellow!80!black,shift={(interior.north west)}]
(interior.south west) grid (interior.north east);
\end{tcbclipinterior}},
title={Solution of Exercise~\ref{exercise@#1} on page~\pageref{exercise@#1}:},
phantomlabel={solution@#1},
attach title to upper=\par,
}{\input{#2}}

\tcbset{no solution/.style={no recording,after upper=}}

\begin{document}
\chapter{The first chapter}

\section{Exercises}
\tcbstartrecording
\begin{exercise}
Exercise with inlined footnotes, \footnoteC{inlined footnote 1} and \footnoteC{inlined footnote 2}, in the question.
\tcblower
Exercise with inlined footnotes, \footnoteC{inlined footnote 1} and \footnoteC{inlined footnote 2}, in the answer.
\end{exercise}
\footnotetextC[1]{inlined footnote 1}
\footnotetextC[2]{inlined footnote 2}
\begin{exercise}
Exercise with usual footnotes, \footnote{footnote 1} and \footnote{footnote 2}, in the question.
\tcblower
Exercise with usual footnotes, \footnote{footnote 1} and \footnote{footnote 2}, in the answer.
\end{exercise}
\tcbstoprecording
\section{Solutions of exercises}
\tcbinputrecords

\end{document}

and it's compilation, using xelatex:

Answer 1

If I understand your question correctly, you want your footnotes set in the 'para' style of manyfoot, but inside the tcolorbox. The package paranotes can do this for you.

If not for the complex 'exercise-solution' tcolorboxes, it would be easier to automate the 'parnotes', which rely on an implicit or explicit \parnotes command to print the notes. But it is not too much trouble to do it with partial automation.

\documentclass{book}

\usepackage[most]{tcolorbox}
\tcbuselibrary{skins,breakable,xparse}

\usepackage{polyglossia}
\setmainlanguage{english}

\usepackage{parnotes}

\NewTColorBox[auto counter,number within=chapter]{exercise}{+O{}}{%
  enhanced,
  colframe=green!20!black,
  colback=yellow!10!white,
  coltitle=green!40!black,
  fonttitle=\bfseries,
  underlay={\begin{tcbclipinterior}
      \shade[inner color=green!80!yellow,outer color=yellow!10!white]
      (interior.north west) circle (2cm);
      \draw[help lines,step=5mm,yellow!80!black,shift={(interior.north west)}]
      (interior.south west) grid (interior.north east);
    \end{tcbclipinterior}
  },
  title={Exercise~ \thetcbcounter:},
  label={exercise@\thetcbcounter},
  attach title to upper=\quad,
  after upper={\par\hfill\textcolor{green!40!black}%
    {\itshape Solution on page~\pageref{solution@\thetcbcounter}}%
    \par\parnotes
  },
  lowerbox=ignored,
  savelowerto=exercise-\thetcbcounter.tex,
  record={\string\solution{\thetcbcounter}{exercise-\thetcbcounter.tex}},
  #1,
  code={\parnotereset}, % <-- parnotes
}

\NewTotalTColorBox{\solution}{mm}{%
  enhanced,
  colframe=red!20!black,
  colback=yellow!10!white,
  coltitle=red!40!black,
  fonttitle=\bfseries,
  underlay={\begin{tcbclipinterior}
      \shade[inner color=red!50!yellow,outer color=yellow!10!white]
      (interior.north west) circle (2cm);
      \draw[help lines,step=5mm,yellow!80!black,shift={(interior.north west)}]
      (interior.south west) grid (interior.north east);
    \end{tcbclipinterior}},
  title={Solution of Exercise~\ref{exercise@#1} on page~\pageref{exercise@#1}:
  },
  phantomlabel={solution@#1},
  attach title to upper=\par,
}{\input{#2}}

\tcbset{no solution/.style={no recording,after upper=}}

\begin{document}

\chapter{The first chapter}

\section{Exercises}

\tcbstartrecording
\begin{exercise}
  1.  Exercise with inlined footnotes, \parnote{inlined footnote 1}
  and \parnote{inlined footnote 2}, in the question.

  % \parnotes % <-- this won't work because of your "Solution on page ..."

  \tcblower

  2.  Exercise with inlined footnotes, \parnote{inlined footnote 1}
  and \parnote{inlined footnote 2}, in the answer.

  \parnotes

\end{exercise}

% \footnotetextC[1]{inlined footnote 1}
% \footnotetextC[2]{inlined footnote 2}

\begin{exercise}
  Exercise with usual footnotes, \footnote{footnote 1} and
  \footnote{footnote 2}, in the question.

  \tcblower

  Exercise with usual footnotes, \footnote{footnote 1} and
  \footnote{footnote 2}, in the answer.
\end{exercise}
\tcbstoprecording

\section{Solutions of exercises}
\tcbinputrecords

\end{document}

Note: I removed your code to write the boxes to another directory (which shouldn't be included in an MWE unless that's the focus of the question).

Answer 2

Based on the answer given by @jon, what I accept, I give an answer of my question, which is really an answer for a developped question... I put this question in arabic environment, a right-to-left environment, and the latin sentences are given inside the commands \LR{} which writes it in left-to-right. I give examples using the manyfoot package, where we see that the footnotes are not written, and an example using parnotes, and we see that the command \LR{\parnotes} writes the footnotes, in left-to-right mode if I want, inside the box.

Here is the .tex file obtained:

\documentclass{book}

\usepackage[most]{tcolorbox}
\tcbuselibrary{skins,breakable,xparse}

\usepackage{polyglossia}
\setmainlanguage[numerals=maghrib]{arabic}
\setotherlanguage{english}
\setmainfont[Script=Arabic,Scale=1.2]{Arial}

\usepackage{parnotes}

\usepackage[para*]{manyfoot}
\DeclareNewFootnote[para]{C}
\makeatletter
\let\c@footnoteC\c@footnote
\makeatother

\renewcommand{\thefootnoteC}{\fnsymbol{footnote}}

\NewTColorBox[auto counter,number within=chapter]{exercise}{+O{}}{%
enhanced,colframe=green!20!black,colback=yellow!10!white,coltitle=green!40!black,
fonttitle=\bfseries,
underlay={\begin{tcbclipinterior}
\shade[inner color=green!80!yellow,outer color=yellow!10!white]
(interior.north west) circle (2cm);
\draw[help lines,step=5mm,yellow!80!black,shift={(interior.north west)}]
(interior.south west) grid (interior.north east);
\end{tcbclipinterior}},
title={Exercise~ \thetcbcounter:},
label={exercise@\thetcbcounter},
attach title to upper=\quad,
after upper={\par\hfill\textcolor{green!40!black}%
{\itshape Solution on page~\pageref{solution@\thetcbcounter}}},
lowerbox=ignored,
savelowerto=solutions/exercise-\thetcbcounter.tex,
record={\string\solution{\thetcbcounter}{solutions/exercise-\thetcbcounter.tex}},
#1
}

\NewTotalTColorBox{\solution}{mm}{%
enhanced,colframe=red!20!black,colback=yellow!10!white,coltitle=red!40!black,
fonttitle=\bfseries,
underlay={\begin{tcbclipinterior}
\shade[inner color=red!50!yellow,outer color=yellow!10!white]
(interior.north west) circle (2cm);
\draw[help lines,step=5mm,yellow!80!black,shift={(interior.north west)}]
(interior.south west) grid (interior.north east);
\end{tcbclipinterior}},
title={Solution of Exercise~\ref{exercise@#1} on page~\pageref{exercise@#1}:},
phantomlabel={solution@#1},
attach title to upper=\par,
}{\input{#2}}

\tcbset{no solution/.style={no recording,after upper=}}

\renewcommand{\theparnotemark}{\fnsymbol{parnotemark}} %% The mark for parnote
\renewcommand{\parnotefmt}[1]{\footnotesize\rmfamily
 \noindent\rule{\linewidth}{.5pt}\\ %% The rule before the footnotes
 \noindent #1\par
 \noindent\rule{\linewidth}{.5pt} %% The rule below the footnotes
 }
\begin{document}
\chapter{The first chapter}
\section{Exercises}
\tcbstartrecording
\begin{exercise}
\LR{Exercise with inlined footnotes, using manyfoot, \footnoteC{inlined footnote 1} and \footnoteC{inlined footnote 2}, in the question.}
\tcblower
\LR{Exercise with inlined footnotes, using manyfoot, \footnoteC{inlined footnote 1} and \footnoteC{inlined footnote 2}, in the answer.}
\end{exercise}
\begin{exercise}
\LR{1.  Exercise with inlined footnotes, using parnotes, \parnote{inlined footnote 1} and \parnote{inlined footnote 2}, in the question.}
\LR{\parnotes}
\tcblower
\LR{2.  Exercise with inlined footnotes, using parnotes, \parnote{inlined footnote 1} and \parnote{inlined footnote 2}, in the answer.}
\LR{\parnotes}
\end{exercise}

\begin{exercise}
\LR{Exercise with usual footnotes, \footnote{footnote 1} and \footnote{footnote 2}, in the question.}
\tcblower
\LR{Exercise with usual footnotes, \footnote{footnote 1} and \footnote{footnote 2}, in the answer.}
\end{exercise}
\tcbstoprecording
\section{Solutions of exercises}
\tcbinputrecords
\end{document}

and its compilation, using xelatex: