mdbook-compress

An mdBook backend renderer to generate a single PDF file for a full book.

There are other similar projects, but most rely on chrome in some way to generate a PDF. This project only optionally requires Node.js to be installed for code block syntax highlighting. If you don't want highlighting you can specify that with highlight = "none" in the config (or set highlight = "no-node" to use the built-in highlighter).

Usage

To use this backend, you'll need to add the following to your book.toml file:

[output.compress]

and install this project

cargo install mdbook-compress

If you want to keep the default HTML output, you'll also need to add in [output.html] if it's not already there

The resulting PDF will end up in /book/compress/<book-title>.pdf. If you want to have a look at an example PDF, you can have a look at this one which is the whole reaoson this project exists in the first place.

Config options

There are a few config options. They're all below and have a few comments to explain things. All the values are the default values.

[output.compress]
# You can optionally specify a subtitle. If you don't the PDF
# won't include a subtitle
subtitle = ""
# If you want to use custom fonts, specify them here.
# The value is a path relative to 'theme/fonts' under your book root
font.regular = ""
font.bold = ""
font.italic = ""
font.bold-italic = ""
font.monospace = ""
# Font sizes. Any heading after H6 will use the H6 font size
# All font sizes will become a u8
font_size.title = 12
font_size.h1 = 11
font_size.h2 = 10
# H3 is also used for the subtitle
font_size.h3 = 8
font_size.h4 = 7
font_size.h5 = 6
font_size.h6 = 6
font_size.text = 5
# Page configs
# Page size. One of: A4, US letter, US legal (see below for custom sizes)
page.size = "A4"
page.landscape = false
# Insert a page break between chapters (markdown files)
page.new_pages = false
# Line and margin spacing. Both measured in millimeters (f64 internally)
page.spacing.line = 1.5
page.spacing.heading = 2.0
page.spacing.margin = [20.0, 20.0]
# See the highlighting section below
highlight = "all"

Custom page sizes

If you need a custom page size, you can give the width and height (x and y) dimensions in millimeters like this

page.size = { x = "width", y = "height" }

Highlighting

Code highlighting with highlight.js (what mdbook uses for the HTML) is pretty slow because it requires calling a node command. To fix this, this project uses syntect to do any highlighting. However, if you specify a custom highlight.js script in the themes directory of your book, the code will use that.

You can change this though. The highlight value of the config can be one of:

• "all" (default)
  Use highlight.js file when given otherwise use syntect
• "no-node"
  Always use syntect even if a highlight.js file is given. In this case you can give .sublime-syntax files in your theme folder that will be used for highlighting. This way you can have a faster alternative to Node whilst keeping custom highlighting
• "none"
  Don't do any highlighting

It's worth noting that the highlighting colours for syntect and highlight.js are different because they're different programs

If you use syntect, you can provide a custom theme.tmtheme file in your theme directory. If this is a valid theme, that'll get used for highlighting. If not, the theme base16-ocean.light is used instead.

Why does it take so long?

If you're using a custom highlight.js file, this might make the renderer a bit slow. This is due to having to call Node.js for each code block. You should only use this if you require highlighting a language not supported by syntect.

Things still to add

• Images (This is not possible with genpdf... at the moment)
• Custom highlight.js theme application (Can have a custom syntect theme)

Dependencies

If you want to know what different dependencies are used for, here you go. The descriptions are all a bit general, because anything more specific would make the table too big.