Collecting contents of environment and store them for later retrieval

Question

I want to store contents of an environment and add them to a macro or command I could easily retrieve them, but I do not want to use the collect package. Are there any alternatives?

\documentclass{article}
\usepackage{environ}
\usepackage{blindtext}



\NewEnviron{env}{
\global\let\content\BODY
%i want to add content to running list and later get whole contents
}

\begin{document}
  \begin{env}
 text text text\\
 \end{env}

\blindtext


\begin{env}
  moretext moretext more text\\
\end{env}

\end{document}

Answer 1

You can print the saved environments by “name” or all of them.

This requires two runs (when the saved environments change), because of the usage of \label.

Update

Since etex methods are now discouraged, here's a reimplementation with expl3.

\documentclass{article}
\usepackage{refcount}

\ExplSyntaxOn

\newcounter{savedenv}
\seq_new:N \g_ephraim_savedenv_seq

\NewDocumentEnvironment{savedenv}{ o +b }
 {
  \refstepcounter{savedenv}
  \IfValueT{#1}{\label{savedenv@#1}}
  \seq_gput_right:Nn \g_ephraim_savedenv_seq { #2 }
}{}

\NewDocumentCommand{\printsaved}{m}
 {% #1 is a list of labels
  \clist_map_inline:nn { #1 }
   {
    \seq_item:Nn \g_ephraim_savedenv_seq { \getrefnumber{savedenv@##1} }
    \par
   }
 }
\NewDocumentCommand{\printallsaved}{}
 {
  \seq_use:Nn \g_ephraim_savedenv_seq { \par }
 }


\ExplSyntaxOff

\begin{document}

\begin{savedenv}[a]
Something for a
\end{savedenv}

\begin{savedenv}[b]
Something for b
\end{savedenv}

\begin{savedenv}
Something with no label
\end{savedenv}

\textbf{Let's print them}

This is a: \printsaved{a}

This is b: \printsaved{b}

\textbf{Let's print them in different order}

\printsaved{b,a}

\textbf{Print all of them}

\printallsaved

\end{document}

Original code

\documentclass{article}
\usepackage{etex,environ,refcount}

\globtoksblk\savedenvtoks{1000}
\newcounter{savedenvcount}

\NewEnviron{savedenv}[1][]{%
  \refstepcounter{savedenvcount}%
  \if\relax\detokenize{#1}\relax
  \else
    \label{#1}%
  \fi
  \global\toks\numexpr\savedenvtoks+\value{savedenvcount}\relax=\expandafter{\BODY}%
}
\toks\savedenvtoks={??}

\newcommand{\printsaved}[1]{%
  \the\toks\numexpr\savedenvtoks+\getrefnumber{#1}\relax
}

\makeatletter
\newcommand{\printallsaved}{%
  \@tempcnta=\z@
  \loop
    \ifnum\@tempcnta<\value{savedenvcount}
    \advance\@tempcnta\@ne
    \the\toks\numexpr\savedenvtoks+\@tempcnta\relax\par
  \repeat
}
\makeatother

\begin{document}

\begin{savedenv}[a]
Something for a
\end{savedenv}

\begin{savedenv}[b]
Something for b
\end{savedenv}

\begin{savedenv}
Something with no label
\end{savedenv}

\textbf{Let's print them}

This is a: \printsaved{a}

This is b: \printsaved{b}

\textbf{Print all of them}

\printallsaved

\end{document}

You can save up to 1000 environments, but you can change the number in the obvious way. Don't try setting the number to much more than 30000.

Answer 2

I suggest to use newenviron package instead of environ, because it defines a \envnamebody command.

Note: Do not call your environment env, because it will collide with the implicit \envbody command always being defined for any environment by newenviron.

After changing to that, one can use the etoolbox - list commands \listgadd etc. and forlistloop do add the current content to the list and processing later on, e.g. printing it.

You need a 'printing' command, I named it \showlist.

The content is glued together without any spacing between at the end of the environment code.

Edited version -- glueing 'arbitrary(?)' texts together

\documentclass{article}
\usepackage{tcolorbox}
\usepackage{newenviron}
\usepackage{blindtext}
\usepackage{etoolbox}

\def\mylist{}%
\listadd{\mylist}{}% Initialize list

\newrobustcmd{\myexpandingcommand}[1]{%
\listgadd{\mylist}{#1}%
}%

\newenviron{content}{%
}{%
\noindent\textbf{\LARGE \textcolor{blue}{Environment content}}  % Remove later on!

\noindent\envbody%
\expandafter\myexpandingcommand\expandafter{\envbody}%
\endgraf\bigskip\bigskip% Can be removed
}%




% Macro showing the current list element%
\newrobustcmd{\showlist}[1]{%
#1%
}%

\begin{document}

\begin{content}  % Store some content%
\blindtext%
\end{content}

\noindent\textbf{\LARGE \textcolor{green}{Text content outside of environment}}  % Can be removed, just for diagnosis/test

\noindent\blindtext
\endgraf\bigskip

\begin{content}

\textbf{\textcolor{red}{Even more text and now even some math: \huge \(\displaystyle\int\limits^{b}_{a} f(x) dx\)}}%

\end{content}


\begin{center}
\begin{tcolorbox}[width=0.8\textwidth,title={Now the combined content of the list}]
\forlistloop{\showlist}{\mylist}%
\end{tcolorbox}%
\end{center}

\end{document}

Answer 3

I leave this answer here because they were inspirational for the creation of the scontents package. With this package it is quite easy to do what you are looking for. Everything stored in memory including verbatim content. If you wish you can also save the content in external files using the key write-env=file.tex. I am always inclined to store the content in memory:)

\documentclass{article}
\usepackage{scontents}
\pagestyle{empty}
\begin{document}
\begin{scontents}[store-env=main]
Something for main A.
\end{scontents}

\begin{scontents}[store-env=main]
Something for \verb|main B|.
\end{scontents}

\begin{scontents}[store-env=other]
Something for \verb|other|.
\end{scontents}

\textbf{Let's print them}

This is first stored in main: \getstored[1]{main}\par
This is second stored in main: \getstored[2]{main}\par
This is stored in other: \getstored[1]{other}

\textbf{Print all of stored in main}\par
\foreachsc[sep={\\[10pt]}]{main}
\end{document}

Saludos

Answer 4

This answer concerns collecting and storing the content of the environment verbatim. (some advantages includes executing the content with catcode equal to catcode at retrieval time, which can be done with e.g. \scantokens), or otherwise you may want to pass the selected content to Python or something similar)

Other options:

• Using \VerbatimOut from fancyvrb for storing the content verbatim (requires external file).
• LuaTeX-specific solution In LuaLaTeX, how do I pass the content of an environment to Lua verbatim?
• A macro written by another user on the site
• Defining your own environment/command that manipulates the catcodes and \endlinechar manually.

---

Method	Tab	Space	Newline	Final newline	Letters	Others
+v argument type in xparse (*)	Does not work (link contains patch to workaround)	space catcode	\ExplSyntax-Off: char 13 cat other, \ExplSyntax-On: first character is same character as \endlinechar (inherent TeX limitation, cannot fix), remaining are same as above	user specified	other cat	other cat
\collectverb and \Collectverb (*)	\ExplSyntax-On: ignored; \ExplSyntax-Off: Start of line: stripped, otherwise: space with space catcode	active space	\ExplSyntax-On: active space, \ExplSyntax-Off: active char 13	user specified	letter cat	other cat
\collectverb* and \Collectverb* (*)	\ExplSyntax-On: ignored; \ExplSyntax-Off: Start of line: stripped, otherwise: same as space →	space with other cat	\ExplSyntax-On: space, \ExplSyntax-Off: active char 13	user specified	letter cat	other cat
\collect-verbenv and \Collect-verbenv (strips first line in \ExplSyntaxOn environment)	active tab (char 9)	active space	active newline (char 13)	user specified	letter cat	other cat
file-contents-defmacro environment	Controlled by \FCDtab-tomacro, default: same as space	Active, default expand to space (space cat)	Active, char 13, default expand to \par	Always present	letter cat	other cat
scontents internal macro	other cat	other cat	char 10 cat other	Stripped	letter cat	other cat

(*): not really an environment

Remark:

1. For the ones delimited with {}: {} can be used as delimiter, as long as inner {} is balanced.
2. The line \begin{...} and \end{...} usually have to be on separate line.
3. Most of the time, the behavior with tab/newline is "the default one defined by the implementation" if the author does not do anything special with it. (can be changed by redefining \endlinechar or setting their catcode manually etc.)
4. What the active characters expanded to can be changed by redefining their meaning.
5. scontents macro is an internal method, might break at any time.
6. As mentioned in the documentation, it can be nested in most cases.
7. \getstored is not expandable.
8. However there's an internal method (see example code below)

\begin{scontents}[store-env=test]
\a test & test %comment

second line
third line
\end{scontents}

\ExplSyntaxOn

\tl_new:N \my__a
are stored as characters. 
\tl_set:Nx \my__a { \__scontents_getfrom_seq:nn {1} {test} }

\tl_remove_once:NV \my__a \c__scontents_hidden_space_str
\tl_analysis_show:N \my__a

\ExplSyntaxOff

9. The environments defined by the environ package does not store the content verbatim.
10. The environments defined by the newenviron package does not store the content verbatim. (plus another issue I mentioned in a comment Collecting contents of environment and store them for later retrieval )