pandoc doesn't text-wrap code blocks when converting to pdf

Question

I'm using pandoc with xelatex engine to convert markdown to pdf. I'm running pandoc like this:

pandoc -s 'backbone-fundamentals'.md -o 'backbone-fundamentals'.pdf \
    --title-prefix 'Developing Backbone.js Applications' \
    --normalize \
    --smart \
    --toc \
    --latex-engine=`which xelatex`

If a code line is longer than the pdf document width it just gets cutoff. Is there anyway to have pandoc text wrap long code lines?

Answer 1

Not having the text wrapped is (part of) the point of code blocks. As far as I know, the only way to wrap the code is manually. For most languages, not exceeding a certain line length is considered good style anyway.

If your lines are length-limited but still too long for your LaTeX-generated pdf, consider reducing the font size for code blocks. For this you need to change the LaTeX template used by pandoc. A look at this answer to "How to set font size for all verbatims in Beamer presentation?" should get you started.

Answer 2

If you have a recent installation of LaTeX that includes the fvextra package, then there is a simple solution, recently suggested by jannick0.

Modify your YAML header options to include

\usepackage{fvextra}
\begin{Highlighting}[breaklines,numbers=left]

and compile with xelatex.

For instance,

---
header-includes:
 - \usepackage{fvextra}
 - \DefineVerbatimEnvironment{Highlighting}{Verbatim}{breaklines,commandchars=\\\{\}}
---

~~~~~{.java}
this is a very long long long long long long long long long long long long long line which is broken
~~~~~~

when compiled with

pandoc input.md --pdf-engine=xelatex -o output.pdf

gives

If you had the .numberLines option, i.e.,

---
header-includes:
 - \usepackage{fvextra}
 - \DefineVerbatimEnvironment{Highlighting}{Verbatim}{breaklines,commandchars=\\\{\}}
---


~~~~~{.java .numberLines}
this is a very long long long long long long long long long long long long long line which is broken
~~~~~~

then the same command would produce