/asciidoctor-web-pdf

Convert AsciiDoc documents to PDF using web technologies

Primary LanguageJavaScriptMIT LicenseMIT

Asciidoctor Web PDF

Build npm version

A PDF converter for AsciiDoc based on web technologies. It allows complex layouts to be defined with CSS and JavaScript, while writing the content in AsciiDoc.

Document
source / PDF
Letter
Source / PDF
Book
source / PDF
Cheat sheet
Source / PDF
Resume
Source / PDF
Slides
Source / PDF

Asciidoctor Web PDF has support for LaTeX-style mathematical equations (via MathJax) and syntax highlighting (via highlight.js). Many more features can be added by importing an existing JavaScript or CSS framework.

Highlights

  • Complex layouts with CSS and JavaScript
  • SVG icons with Font Awesome 5
  • PDF document outline (i.e., bookmarks)
  • Table Of Contents
  • Document metadata (title, authors, subject, keywords, etc)
  • Fully customizable template
  • Syntax highlighting with Highlight.js
  • Page numbering
  • Preview mode
  • STEM support with MathJax 3

Installation

Run from pre-compiled binaries

Asciidoctor Web PDF is available for each release as a zip file for Windows 64-bit, Linux 64-bit and macOS 64-bit (x86-64).

Go to the releases page and download the appropriate binary for your platform (under "Assets"). Extract this to a folder of your choosing.

From a command line in this folder you can then run the asciidoctor-web-pdf command.

Install using npm

To run from source, you need Node installed on your machine to install and run Asciidoctor Web PDF. The best way to install Node is to use nvm (Node Version Manager).

How to set up nvm on my machine

Install nvm and Node on Linux or macOS

Follow these installation instructions to set up nvm on your machine.
Once you've installed nvm, open a new terminal and install the latest Node LTS release.

$ nvm install --lts

The above command will install the latest LTS release of Node and automatically set it as your default alias.

Install nvm and Node on Windows

Follow these installation instructions to set up nvm on your machine.
Once you've installed nvm, open a new, regular PowerShell terminal, and install Node using nvm.

$ nvm install 14.15.5
$ nvm use 14.15.5

The above commands will install Node v14.15.5 and enable it.

We recommend using the latest long term support (LTS) release of Node. While you can use other versions of Node, Asciidoctor Web PDF is only tested against active LTS releases.

Install in a project directory

You can opt to install Asciidoctor Web PDF in a project directory, such as the directory where your AsciiDoc files are stored. If you don't have a package.json file in your project directory, you can create one using:

$ npm init -y

To install Asciidoctor Web PDF in a project directory, move into your project directory and type:

$ npm i @asciidoctor/core asciidoctor-pdf --save-dev

The dependencies will be in installed under the node_modules folder in the current directory and npm will save all modules listed as devDependencies in the package.json file.

Verify that the asciidoctor-web-pdf command is available. If you are running a recent version of npm, you can use either: npm x asciidoctor-web-pdf --version (or npx asciidoctor-web-pdf --version)

TIP: If you are running an older version, you might need to use the longer format: $(npm bin)/asciidoctor-web-pdf --version.

If installation was successful, the command should report the version of Asciidoctor Web PDF.

$ npx asciidoctor-web-pdf --version
Asciidoctor Web PDF 1.0.0-alpha.12 using Asciidoctor.js 2.2.1 (Asciidoctor 2.0.12) [https://asciidoctor.org]
Runtime Environment (node v14.15.5 on linux)
CLI version 3.4.0

Install globally using npm

IMPORTANT: This installation procedure is only applicable if you are not using a Node.js version manager like nvm (Node Version Manager). Otherwise, npm will try to install Asciidoctor Web PDF in the system space which has proven to be unreliable!

To install Asciidoctor Web PDF package globally, open a terminal and type:

$ npm i -g @asciidoctor/core asciidoctor-pdf

NOTE: Installing Asciidoctor Web PDF globally makes asciidoctor-web-pdf command available on your PATH. In other words, the command asciidoctor-web-pdf will be available globally, so you can run it from any directory.

Verify that the asciidoctor-web-pdf command is available on your PATH by running:

$ asciidoctor-web-pdf --version

NOTE: If you get an error about Executions Policies when running this command on PowerShell, try to use the following command instead: $ asciidoctor-web-pdf.cmd --version.

TIP: If you prefer Yarn over npm, use this command to install the Asciidoctor Web PDF package:

$ yarn global add @asciidoctor/core asciidoctor-pdf

Get started

Asciidoctor Web PDF provides a standard document layout. To convert an AsciiDoc document using this layout, open a terminal and type:

$ asciidoctor-web-pdf document.adoc

IMPORTANT: Asciidoctor Web PDF relies on Puppeteer to generate a PDF from a Web page. If you get the following error, make sure that all the necessary dependencies are installed.

> Unable to generate the PDF - Error: TimeoutError: Timed out after 30000 ms while trying to connect to Chrome!

Configuration

The standard document layout can be configured depending on your needs.

STEM support

To activate equation and formula support, set the stem attribute in the document's header (or by passing the attribute to the command line):

$ asciidoctor-web-pdf document.adoc -a stem

Title page

The title page is enabled if either of these conditions are met:

  • The document has the book doctype.
  • The title-page attribute is set (with an empty value) in the document header.
$ asciidoctor-web-pdf document.adoc -a title-page

Custom styles

You can provide a custom stylesheet using the stylesheet attribute. A custom stylesheet does completely replace the default stylesheet.

$ asciidoctor-web-pdf document.adoc -a stylesheet="custom.css"

TIP: You can also provide a custom stylesheet in addition to all the default styles using the + prefix:

$ asciidoctor-web-pdf document.adoc -a stylesheet="+custom.css"

Notice the + before custom.css, it means that the stylesheet will be included after all the default styles. This is particularly useful when you want to override a few styles.

The stylesheet attribute can accept multiple comma-delimited values (without spaces). This can be used to begin with a base stylesheet and then apply supplementary content.

$ asciidoctor-web-pdf document.adoc -a stylesheet="custom.css,override.css"

It's also possible to use the default stylesheet and add custom styles with a custom stylesheet. All default stylesheets are available under the prefix asciidoctor-pdf/css/:

$ asciidoctor-web-pdf document.adoc -a stylesheet="asciidoctor-pdf/css/asciidoctor.css,asciidoctor-pdf/css/document.css,custom.css"

You can also specify where the stylesheets are located with the stylesdir attribute.

$ asciidoctor-web-pdf document.adoc -a stylesdir=css -a stylesheet="custom.css,override.css"

Front cover image

When using a title page (see above), you might want to set a front cover image. To do that, you will need to add a few lines of CSS.

Here's a complete example:

  1. Create a file named orly.adoc with the following content:
= Hoping This Works
:doctype: book

== Guessing

The first step is guessing.

We are using :doctype: book to get a title page.

  1. Create a file named orly.css with the following content:
@page :first {
  background-size: contain;
  background-image: url("./orly.jpg");
}

/* move the book title to the correct location */
#cover > h1 {
  color: white;
  margin-top: 8cm;
  font-size: 7rem;
}
  1. Download the image orly.jpg and put it next to the orly.adoc file.

  2. Open a terminal and type:

    $ asciidoctor-web-pdf orly.adoc -a stylesheet="+orly.css"

The above command will create a file named orly.pdf which should look like:

front-cover-image

Docinfo

You can add custom content to the head, header or footer of the output document using docinfo files. Docinfo files are useful for injecting auxiliary metadata, stylesheet, and script information into the output not added by the converter.

In addition, you can add running content to the output document. Running content can then be positioned via CSS on the top, bottom, left or right margins of pages. This can come in handy when you want to repeat complex elements (address, contact...) on all pages for documents like invoices or reports. If you want to learn more about running elements, please read the following section Running elements.

IMPORTANT: You will need to declare running elements as running content via CSS. Otherwise, running elements will be visible on the page.

To enable docinfo files, you need to configure the scope using the docinfo attribute. The scope defines if the docinfo files apply for a specific document ("private") or for all documents in the same directory ("shared").

Mode Location Behavior Docinfo file name
Private Head Adds content to <head> for <docname>.adoc files. <docname>-docinfo-pdf.html
Private Header Adds content to start of document for <docname>.adoc files. <docname>-docinfo-header-pdf.html
Private Footer Adds content to end of document for <docname>.adoc files. Useful for supporting Paged.js hooks and custom JavaScript <docname>-docinfo-footer-pdf.html
Private Running Adds running content to start of document for <docname>.adoc files. <docname>-docinfo-running-pdf.html
Shared Head Adds content to <head> for any document in same directory. docinfo-pdf.html
Shared Header Adds content to start of document for any document in same directory. docinfo-header-pdf.html
Shared Footer Adds content to end of document for any document in same directory. Useful for supporting Paged.js hooks and custom JavaScript docinfo-footer-pdf.html
Shared Running Adds running content to start for any document in same directory. docinfo-running-pdf.html

To specify which file(s) you want to apply, set the docinfo attribute to any combination of these values:

  • private-head
  • private-header
  • private-footer
  • private-running
  • private (alias for private-head,private-header,private-footer,private-running)
  • shared-head
  • shared-header
  • shared-footer
  • shared-running
  • shared (alias for shared-head,shared-header,shared-footer,shared-running)

Setting docinfo with no value is equivalent to setting the value to private.

For example:

:docinfo: shared,private-footer

This docinfo configuration will apply the shared docinfo head, header, running and footer files, if they exist, as well as the private footer file, if it exists.

Running elements

Running elements can be positioned on the top, bottom, left or right margins of pages. Let's take a concrete example where we want to display an address block in the bottom left box of every page.

<address class="contact-us">
  <strong>Example Inc.</strong><br>
  1234 Example Street<br>
  Antartica, Example 0987<br>
  <abbr title="Phone">P:</abbr> (123) 456-7890
</address>

First, you will to define your element as running using the position property. Here, we are using runningContact as an identifier, but you can use any name that makes sense to you:

.contact-us {
  position: running(runningContact)
}

Then, place the element into a margin box with the element() function via the content property:

@page {
  @bottom-left {
    content: element(runningContact)
  }
}

As you can see, we are using the identifier runningContact defined earlier. The above definition will effectively remove the .contact-us element from the page and repeat it on every page in the bottom left box.

Here's a complete example:

  1. Create a file named report.adoc with the following content:
= 2021 Annual Report
:docinfo: private
  1. Create a file named report-docinfo-running-pdf.html with the following content:
<address class="contact-us">
  <strong>Handicap International</strong><br>
  138, avenue des Frères Lumière<br>
  69008 Lyon - France
</address>
  1. Create a file named report.css with the following content:
.contact-us {
  width: 6cm;
  position: running(runningContact)
}

@page {
  margin: 1cm 2cm 4cm 2cm;
}

@page :right {
  @bottom-left {
    content: element(runningContact)
  }

  @bottom-right {
    content: counter(page);
    margin: 10pt 10pt 30pt 0;
  }
}

@page :left {
  @bottom-right {
    content: element(runningContact)
  }

  @bottom-left {
    content: counter(page);
    margin: 10pt 0 30pt 10pt;
  }
}
  1. Open a terminal and type:

    $ asciidoctor-web-pdf report.adoc -a stylesheet="+report.css"

The above command will create a file named report.pdf which should look like:

complex-footer

TIP: Please note that, in this case, you don't need to use a docinfo file, you can declare the "contact us" block directly in the AsciiDoc file. In other words, you should get the same result if you are using the following content:

= 2021 Annual Report

[.contact-us]
--
*Handicap International* +
138, avenue des Frères Lumière +
69008 Lyon - France
--

Asciidoctor extensions

Asciidoctor Web PDF can use Asciidoctor extensions written in JavaScript from the CLI. For instance, if you want to use the Asciidoctor Kroki extension, you first need to install it:

$ npm i asciidoctor-kroki

Then, you can use the following command to load this extension:

$ asciidoctor-web-pdf --require asciidoctor-kroki document.adoc

It's also possible to use an extension from a JavaScript file. For instance, if you want to load a local extension declared in a JavaScript file named my-asciidoctor-extension.js, then you can use the following command:

$ asciidoctor-web-pdf --require ./my-asciidoctor-extension.js document.adoc

NOTE: Please note that the extension should export a function named register, otherwise the extension won't be registered:

module.exports.register = function (registry) {
  if (typeof registry.register === 'function') {
    registry.register(function () {
      this.block(function () {
        // ...
      })
    })
  } else if (typeof registry.block === 'function') {
    registry.block(function () {
      // ...
    })
  }
  return registry
}

Diagrams

You can use the Asciidoctor Kroki extension to render diagrams in your PDF. In this example, we create a file named piracy.adoc with the following content:

piracy.adoc

= Piracy

Piracy is an act of robbery or criminal violence by ship upon another ship,
typically with the goal of stealing rum and other valuable items or properties.

Here's what a pirate looks like!

[nomnoml]
....
[Pirate|eyeCount: Int|raid();pillage()|
  [beard]--[parrot]
  [beard]-:>[foul mouth]
]

[<abstract>Marauder]<:--[Pirate]
[Pirate]- 0..7[mischief]
[jollyness]->[Pirate]
[jollyness]->[rum]
[jollyness]->[singing]
[Pirate]-> *[rum|tastiness: Int|swig()]
[Pirate]->[singing]
[singing]<->[rum]
....

Kroki supports more than a dozen diagram libraries. In the above example, we are using the nomnoml UML diagram library.

NOTE: Please note, that you will need to install asciidoctor-kroki, using npm i asciidoctor-kroki.

You can use the following command to generate a PDF:

$ asciidoctor-web-pdf --require asciidoctor-kroki piracy.adoc

Here's the result: piracy.pdf

Custom layout

It's also possible to create your own layout by extending the default HTML 5 converter. To create a new layout you will need some JavaScript knowledge.

Let's say that we want to override how the document node is converted.

module.exports = {
  document: (node) => `<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<link href="./layout.css" rel="stylesheet">
</head>
<body>
${node.getContent()}
</body>`,
}

In the above example, we are using Template Literals but you can use your favorite template engine. You can also override other elements.

Complete list of elements
  • document
  • embedded
  • outline
  • section
  • admonition
  • audio
  • colist
  • dlist
  • example
  • floating-title
  • image
  • listing
  • literal
  • stem
  • olist
  • open
  • page_break
  • paragraph
  • preamble
  • quote
  • thematic_break
  • sidebar
  • table
  • toc
  • ulist
  • verse
  • video
  • inline_anchor
  • inline_break
  • inline_button
  • inline_callout
  • inline_footnote
  • inline_image
  • inline_indexterm
  • inline_kbd
  • inline_menu
  • inline_quoted

The function takes one parameter, called node. Depending on the context a node can be a Block, a Section, a List. or a Table. Block, Section, List and Table extends AbstractBlock which extends AbstractNode.
If you want to learn more, please read the Asciidoctor.js API documentation.

To help you get started, we provides a few alternative layouts in the examples directory:

Layout Template file
Letter examples/letter/template.js
Book examples/book/template.js
Slides examples/slides/template.js
Resume examples/resume/template.js
Cheat sheet (Snyk) examples/cheat-sheet/snyk/template.js

To enable a custom layout, use the --template-require command line option. For instance, if I want to use the cheat sheet layout on examples/cheat-sheet/maven-security-cheat-sheet.adoc:

$ asciidoctor-web-pdf ./examples/cheat-sheet/maven-security-cheat-sheet.adoc --template-require ./examples/cheat-sheet/snyk/template.js

It will produce a file named examples/cheat-sheet/maven-security-cheat-sheet.pdf.

How does it work?

Asciidoctor Web PDF is using an HTML 5 converter to convert an AsciiDoc document to an HTML 5 page. Puppeteer will then run a headless Chrome to generate a PDF from the HTML 5 page.

To paginate content in the browser, we are using Paged.js, an open-source library, that acts as a polyfill for Paged Media and Generated Content for Paged Media W3C specifications.

This project is heavily inspired by ReLaXed.

The file template.js defines how the AsciiDoc content should be converted to HTML 5. Puppeteer will then run an headless Chrome to generate a PDF from the HTML 5 page.

Contribute!

New contributors are always welcome! If you discover errors or omissions in the source code or documentation, please don't hesitate to submit an issue or open a pull request with a fix.