markdownRendererInputFencedCode + minted package

[l0th3r]

Hi, thanks in advance for your help.

I try to style and add code highlight to the fenced blocks of code from markdown to LaTex.

I successfully setup an override for the \markdownRendererInputFencedCode and the \markdownRendererInputVerbatim to be able to draw a box around the rendering of the fenced blocks of code. I have trouble to combine my implementation with the minted package.

I tried to use \begin{minted} and \inputminted but I have errors everytime when adding it in the override of \markdownRendererInputFencedCode.

Do you have any idea how I could achieve that ?

tex file:

\documentclass{article}

\usepackage{markdown}
\usepackage{tcolorbox}

% markdown settings
\markdownSetup{%
	fencedCode=true,
	fancyLists=true,
	texMathDollars=true,
	inlineNotes=true,
	notes=true,	
	pipeTables=true,
	taskLists=true,
	underscores=false,
	subscripts=true,
	superscripts=true	
}


% Define code block style
\newtcolorbox{codeblock}[2][]{
title={#2},
fonttitle=\scriptsize,
leftrule=1mm,
rightrule=0mm,
toprule=0mm,
bottomrule=0mm,
arc=0mm,
#1}

\global\def\markdownRendererInputVerbatim#1{%
    \verbatiminput{#1}%
}

\global\def\markdownRendererInputFencedCode#1#2#3{%
\begin{codeblock}{#2}%
\markdownRendererInputVerbatim{#1}%
\end{codeblock}
}

\begin{document}
\markdownInput{test.md}
\end{document}

test.md file:

print("hello")

int main(int ac, char** av)
{
    return 0;
}

if (a > 3) {
    moveShip(5 * gravity, DOWN);
}

Result:

[Witiko]

I tried to use \begin{minted} and \inputminted but I have errors everytime when adding it in the override of \markdownRendererInputFencedCode.

In your definition of \markdownRendererInputFencedCode, you should replace \markdownRendererInputVerbatim{#1} with \inputminted{#2}{#1}. This will render file #1 using a Pygments lexer for language #2, such as python, c, and js.

You must always specify a lexer, so that minted knows how to highlight the syntax. See also the documentation of minted.

[l0th3r]

[Witiko]

This seems as expected. I assume that, if you wrote \inputminted{c}{./_markdown_test/8a1c...1ece.verbatim} (replace ... with the rest of the digits) directly in your document, the source code would by correctly typeset by minted.

The issue seems to be caused by the fact that we use a special catcode regime inside \begin{markdown} ... \end{markdown} in which # and % are treated as ordinary characters without any special meaning. While this makes it easier to work with the result of the conversion, especially when the hybrid option is enabled, it may break packages such as minted.

The solution, which is also used by the default fenced code renderer, is to reset the catcode of # before using minted, as follows:

markdown/markdown.dtx

Lines 36616 to 36621 in 3cf013f

	\catcode`\#=6\relax
	\exp_args:NV
	\inputminted
	\l_tmpa_tl
	{ #1 }
	\catcode`\#=12\relax

In your specific case, you would use the following definition:

\global\def\markdownRendererInputFencedCode#1#2#3{%
  \catcode`\#=6\relax
  \begin{codeblock}{#2}%
    \inputminted{#2}{#1}%
  \end{codeblock}%
  \catcode`\#=12\relax
}

I am sorry that I did not notice earlier.

[l0th3r]

Hi @Witiko, thank you for your answer.
It works on my side perfectly !

But I am struggling setting up a conditional logic with inputminted and markdownRendererInputVerbatim.
Since the language must be provided for the minted package to work, I have to check if the fenced block title is empty.

Thats what I did:

\global\def\markdownRendererInputFencedCode#1#2#3{%
\catcode`\#=6\relax
\begin{codeblock}{#2}%
	\if #2\empty
		\markdownRendererInputVerbatim{#1}
	\else
		\inputminted{#2}{#1}%
	\fi
\end{codeblock}
\catcode`\#=12\relax
}

But it doesn't work when there is not title, it works when there is one though. And I never did such thing in Tex, I tried to search on the web but cannot implement anything that works, do you have an idea ?

[Witiko]

You may wish to have a look at how the default inputFencedCode renderer is implemented:

markdown/markdown.dtx

Lines 36575 to 36648 in 3cf013f

	%#### Fenced Code
	% When no infostring has been specified, default to the indented code block
	% renderer.
	%
	% \end{markdown}
	% \begin{macrocode}
	\RequirePackage{ltxcmds}
	\ExplSyntaxOn
	\cs_gset:Npn
	\markdownRendererInputFencedCodePrototype#1#2#3
	{
	\tl_if_empty:nTF
	{ #2 }
	{ \markdownRendererInputVerbatim{#1} }
	% \end{macrocode}
	% \begin{markdown}
	%
	% Otherwise, extract the first word of the infostring and treat it as the name
	% of the programming language in which the code block is written.
	%
	% \end{markdown}
	% \begin{macrocode}
	{
	\regex_extract_once:nnN
	{ \w* }
	{ #2 }
	\l_tmpa_seq
	\seq_pop_left:NN
	\l_tmpa_seq
	\l_tmpa_tl
	% \end{macrocode}
	% \par
	% \begin{markdown}
	%
	% When the \pkg{minted} package is loaded, use it for syntax highlighting.
	%
	% \end{markdown}
	% \begin{macrocode}
	\ltx@ifpackageloaded
	{ minted }
	{
	\catcode`\#=6\relax
	\exp_args:NV
	\inputminted
	\l_tmpa_tl
	{ #1 }
	\catcode`\#=12\relax
	}
	{
	% \end{macrocode}
	% \par
	% \begin{markdown}
	%
	% When the \pkg{listings} package is loaded, use it for syntax highlighting.
	%
	% \end{markdown}
	% \begin{macrocode}
	\ltx@ifpackageloaded
	{ listings }
	{ \lstinputlisting[language=\l_tmpa_tl]{#1} }
	% \end{macrocode}
	% \par
	% \begin{markdown}
	%
	% When neither the \pkg{listings} package nor the \pkg{minted} package is
	% loaded, act as though no infostring were given.
	%
	% \end{markdown}
	% \begin{macrocode}
	{ \markdownRendererInputFencedCode{#1}{}{} }
	}
	}
	}
	\ExplSyntaxOff

We use the LaTeX3 programming language between \ExplSyntaxOn and \ExplSyntaxOff, which makes programming easier.

[l0th3r]

@Witiko Thank you so much for your time you are awesome !

[l0th3r]

Answer

After @Witiko 's help.
Now the renderer override \markdownRendererInputFencedCode will use the minted package only if the fenced block "title" is present, using it as a language for the minted package while using our own environment to wrap the style of the fenced code bloc.

main.tex:

% Create a new environement "codeblock"
\newtcolorbox{codeblock}[2][]{
title={#2},
fonttitle=\scriptsize,
leftrule=1mm,
rightrule=0mm,
toprule=0mm,
bottomrule=0mm,
arc=0mm,
#1}

% Override the renderer of fenced code blocs
\ExplSyntaxOn% enable LaTex3 syntax
\global\def\markdownRendererInputFencedCode#1#2#3{%
	\catcode`\#=6\relax
	\begin{codeblock}{ #2 }
		\tl_if_empty:nTF
		{ #2 }% if the second argument (fence block "title" is empty)
		{ \markdownRendererInputVerbatim{#1} }% render regular verbatim
		{ \inputminted{#2}{#1} }% else render minted text
	\end{codeblock}
	\catcode`\#=12\relax
}
\ExplSyntaxOff% disable LaTex3 syntax

codeblock is a custom environment created with \newtcolorbox from the tcolorbox package.

Result

test-language.md:

``` c++
int main(int arc, char** arv)
{
    std::cout << "Hello World !" << std::endl;
    return 0;
}
```

---

test-no-language.md:

```
int main(int arc, char** arv)
{
    std::cout << "Hello World !" << std::endl;
    return 0;
}
```