Asciidoctor PDF: A native PDF converter for AsciiDoc

Lo and behold, a native PDF converter for AsciiDoc built with Asciidoctor and Prawn!
No more DocBook toolchain.
No more middleman.
It’s just AsciiDoc straight to PDF!

Caution

Project status

Asciidoctor PDF is currently alpha software. Use accordingly. Though the bulk of AsciiDoc content is converter, there’s still work needed to fill in gaps where conversion is incomplete, incorrect or not implemented. Once it’s ready, the project will be moved into the Asciidoctor organization on GitHub.

Prawn, the majestic PDF generator

Asciidoctor PDF is made possible by the amazing Prawn RubyGem. What a gem it is!

Prawn is a nimble PDF writer for Ruby. More important, it’s a hackable platform that offers both high level APIs for the most common needs and low level APIs for bending the document model to accomodate special circumstances.

With Prawn, you can write text, draw lines and shapes and place images anywhere on the page and add as much color as you like. In addition, it brings a fluent API and aggressive code re-use to the printable document space.

To give you a picture, here’s an example that shows how to use Prawn to create a basic PDF document.

Create a basic PDF document using Prawn

require 'prawn'

Prawn::Document.generate 'example.pdf' do
  text 'Hello, PDF creation!'
end

It’s that easy. And it’s just the beginning.

Simply put, Prawn is the killer library for PDF generation we’ve needed to close this critical gap in Asciidoctor. It absolutely takes the pain out of creating printable documents. Picking up from there, Asciidoctor PDF takes the pain out of creating printable documents from AsciiDoc.

Notable Features

Direct AsciiDoc to PDF conversion
Configuration-driven style and layout
PDF document outline (i.e., bookmarks)
Document metadata (title, authors, subject, keywords, etc)
Internal cross reference links
Syntax highlighting with CodeRay or Pygments
Page breaks avoided in block content
Orphan section titles avoided
Table border settings honored

Missing Features

See WORKLOG.

Prerequisites

All that’s needed is Ruby 1.9.3 or better (2.1.2 recommended) and a few RubyGems, which we explain how to install in the next section.

To check you have Ruby available, use the ruby command to query the version installed:

$ ruby --version

If you’re using RVM, we recommend creating a new gemset to work with Asciidoctor and Asciidoctor PDF:

$ rvm use 2.1@asciidoctor-pdf --create

We like RVM because it keeps the dependencies required by various projects isolated.

Getting Started

The Asciidoctor PDF project is published in pre-release on RubyGems.org. You can either install the pre-release version using the following command:

$ gem install --pre asciidoctor-pdf

If you want to syntax highlight source listings, you’ll also want to install CodeRay or Pygments. To be safe, go ahead and install both gems:

$ gem install coderay pygments.rb

Assuming all the required gems install properly, verify you can run the asciidoctor-pdf script:

$ asciidoctor-pdf -v

If you see the version of Asciidoctor PDF printed, you’re ready to use Asciidoctor PDF!

Skip ahead to the Example AsciiDoc document section to start putting Asciidoctor PDF to use. Alternatively, you can follow the steps below to install the project from source.

Retrieve the source code

You can retrieve the Asciidoctor PDF project in one of two ways:

Clone the git repository
Download a zip archive of the repository

Option 1: Fetch using git clone

If you want to clone the git repository, simply copy the GitHub repository URL and pass it to git clone command:

$ git clone https://github.com/asciidoctor/asciidoctor-pdf

Next, change to the project directory:

$ cd asciidoctor-pdf

Option 2: Download the archive

If you want to download a zip archive, click the Download Zip button on the right-hand side of the repository page on GitHub. Once the download finishes, extract the archive, open a console and change to that directory.

Tip	Instead of working out of the asciidoctor-pdf directory, you can simply add the absolute path of the bin directory to your PATH environment variable.

We’ll leverage the project configuration to install the necessary dependencies.

Install the Dependencies

The dependencies needed to use Asciidoctor PDF are defined in the Gemfile at the root of the project. We can use Bundler to install the dependencies for us.

To check you have Bundler available, use the bundle command to query the version installed:

$ bundle --version

If it’s not installed, use the gem command to install it.

$ gem install bundler

Then use the bundle command to install the project dependencies:

$ bundle

Assuming all the required gems install properly, verify you can run the asciidoctor-pdf script using Ruby:

$ ruby ./bin/asciidoctor-pdf -v

If you see the version of Asciidoctor PDF printed, you’re ready to use Asciidoctor PDF!

Let’s grab an AsciiDoc document to distill.

Example AsciiDoc document

If you don’t already have an AsciiDoc document, you can use the example.adoc file found in the examples directory of this project.

example.adoc

= Document Title
Doc Writer <doc@example.com>
:doctype: book
:source-highlighter: coderay
:listing-caption: Listing

A simple http://asciidoc.org[AsciiDoc] document.

== Introduction

A paragraph followed by a simple list with square bullets.

[square]
* item 1
* item 2

Here's how you say "`Hello, World!`" in Prawn:

.Create a basic PDF document using Prawn
[source,ruby]
----
require 'prawn'

Prawn::Document.generate 'example.pdf' do
  text 'Hello, World!'
end
----

It’s time to convert the AsciiDoc document directly to PDF.

Convert AsciiDoc to PDF

Converting to PDF is a simple as running the ./bin/asciidoctor-pdf script using Ruby and passing our AsciiDoc document as the first argument.

$ ruby ./bin/asciidoctor-pdf example.adoc

When the script completes, you should see the file example.pdf in the same directory.

Important

You’ll need to the coderay gem installed to run this example since it uses the source-highlighter attribute with the value of coderay.

Open the example.pdf file with a PDF viewer to see the result.

Figure 1. Example PDF document rendered in a PDF viewer

You’re also encouraged to try converting this README as well as the documents in the examples directory to see more of what Asciidoctor PDF can do. Another good example is the CDI Specification.

The pain of the DocBook toolchain should be melting away about now.

Themes

The layout and styling of the PDF is driven by a YAML configuration file.

See the files default-theme.yml and asciidoctor-theme.yml found in the data/themes directory for examples.

Specify the path to an alternate theme file with the pdf-style attribute. For example to use the built-in asciidoctor theme:

$ ./bin/asciidoctor-pdf -a pdf-style=asciidoctor examples/example.adoc

To refer to a theme at another location you can use the pdf-stylesdir attribute to specify the location of themes. If the pdf-style value does not end in .yml, then the file name is calculated as {pdf-style}-theme.yml located in the pdf-stylesdir directory (which defaults to the built-in data/themes directory).

Optional Scripts

Asciidoctor PDF also provides a shell script that invokes GhostScript (gs) to optimize and compress the generated PDF with minimal impact on quality. You must have Ghostscript installed to use it.

Here’s an example usage:

$ ./bin/optimize-pdf example.pdf

The command will generate the file example-optimized.pdf in the current directory.

Warning

The optimize-pdf script currently requires a Bash shell (Linux, OSX, etc). We plan to rewrite the script in Ruby so it works across platforms (see issue #1)

Important

The optimize-pdf script relies on Ghostscript >= 9.10. Otherwise, it may actually make the PDF larger. Also, you should only consider using it if the file size of the original PDF is > 5MB.

If a file is found with the extension .pdfmarks and the same rootname as the input file, it is used to add metadata to the generated PDF document. This file is necessary to preserve the document metadata since Ghostscript will otherwise drop it. That’s why Asciidoctor PDF always creates this file in addition to the PDF.

Contributing

In the spirit of free software, everyone is encouraged to help improve this project.

To contribute code, simply fork the project on GitHub, hack away and send a pull request with your proposed changes.

Feel free to use the issue tracker or Asciidoctor mailing list to provide feedback or suggestions in other ways.

Authors

Asciidoctor PDF was written by Dan Allen and Sarah White of OpenDevise Inc. on behalf of the Asciidoctor Project.

Copyright

For the full text of the license, see the LICENSE file. Refer to the NOTICE file for information about third-party Open Source software in use.

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