kitabu

kitabu

Kitabu is a framework for creating e-books from Markdown using Ruby. Using Prince PDF generator, you'll be able to get high quality PDFs. Also supports EPUB, Mobi, and HTML generation.

While Prince is too expensive (495USD for a single user license), the free version available at http://www.princexml.com/download generates a PDF with a small logo on the first page, which is removed when sent to a printer; you can use it locally for viewing the results immediately. When you're done writing your e-book, you can use DocRaptor, which have plans starting at $15/mo.

Features

• Write using Markdown
• Book layout support
• Syntax highlight
• Generate HTML, PDF, e-Pub, and Mobi
• Table of Contents automatically generated from chapter titles

Installation

To install Kitabu, you'll need a working Ruby 3.2+ installation. If you're cool with it, just run the following command to install it.

gem install kitabu

After installing Kitabu, run the following command to check your external dependencies.

$ kitabu check

Prince XML: Converts HTML files into PDF files.
Installed.

Calibre's ebook-convert: Converts ePub e-books into .mobi files.
Installed.

There are no hard requirements here; just make sure you cleared the correct dependency based on the formats you want to export to.

Usage

To create a new e-book, just run

$ kitabu new mybook

This command creates a directory mybook with the following structure:

.
├── Gemfile
├── Gemfile.lock
├── Guardfile
├── config
│   ├── helper.rb
│   └── kitabu.yml
├── images
│   ├── kitabu-icon.png
│   ├── kitabu-icon.svg
│   ├── kitabu-word.png
│   ├── kitabu-word.svg
│   ├── kitabu.png
│   └── kitabu.svg
├── output
├── templates
│   ├── epub
│   │   ├── cover.erb
│   │   ├── cover.png
│   │   └── page.erb
│   ├── html
│   │   └── layout.erb
│   └── styles
│       ├── epub.css
│       ├── files
│       │   └── _normalize.css
│       ├── html.css
│       ├── pdf.css
│       └── print.css
└── text
    ├── 01_Getting_Started.md
    ├── 02_Creating_Chapters.md
    ├── 03_Syntax_Highlighting.md.erb
    ├── 04_Dynamic_Content.md.erb
    └── 05_Exporting_Files.md

The config/kitabu.yml file holds some information about your book; so you'll always change it.

The generated structure is actually a good example. So make sure you try it!

There's a generated sample available on the attachments directory • PDF / EPUB / MOBI / HTML.

Now it's time to write your e-book. All your book content will be placed on the text directory. Kitabu requires you to separate your book into chapters. A chapter is nothing but a directory that holds lots of text files. The e-book will be generated using every folder/file alphabetically. So be sure to use a sequential numbering as the name. Here's a sample:

* text
  * 01_Introduction
    * 01_introduction.md
  * 02_What_is_Ruby_on_Rails
    * 01_MVC.md
    * 02_DRY.md
    * 03_Convention_Over_Configuration.md
  * 03_Installing_Ruby_on_Rails
    * 01_Installing.md
    * 02_Mac_OS_X_instructions.md
    * 03_Windows_instructions.md
    * 04_Ubuntu_Linux_instructions.md

If you prefer, you can add a chapter per file:

* text
  * 01_Introduction.md
  * 02_What_is_Ruby_on_Rails.md
  * 03_Installing_Ruby_on_Rails.md

You'll want to see your progress eventually; it's time for you to generate the book PDF. Just run the command kitabu export and your book will be created on the output directory.

Kitabu can generate a Table of Contents (TOC) based on your h2-h6 tags. The h1 tag is discarded because it's meant to be the book title.

To print the TOC, you need to print a variable called toc, using the eRb tag.

<%= toc %>

Using ERB

You can also have .md.erb files. You can mix Markdown and HTML, like the following:

## This the chapter title

<% note do %>
  Make sure you try .md.erb files!
<% end %>

The above content must be placed in a .md.erb file. The generated content will be something like this:

<div class="note info">
  <p>Make sure you try .md.erb files!</p>
</div>

The note helper is built-in and can accept a different note type.

<% note :warning do %>
  Make sure you write valid ERB code.
<% end %>

You can see available helpers on https://github.com/fnando/kitabu/blob/main/lib/kitabu/markdown.rb.

Syntax Highlighting

To highlight code, use fenced code blocks.

``` ruby
class User < ActiveRecord::Base
  validates_presence_of :login, :password, :email
  validates_uniqueness_of :login, :email
end
```

You can even provide options:

```php?start_inline=1&line_numbers=1
echo "Hello World";
```

• We use Redcarpet for Markdown processing.
• We use Rouge for syntax highlighting.

The following Redcarpet options are enabled:

• autolink
• fenced_code_blocks
• footnotes
• hard_wrap
• highlight
• no_intra_emphasis
• safe_links_only
• space_after_headers
• strikethrough
• superscript
• tables

Using custom fonts

You can use custom fonts for your PDF. Just add them to the fonts directory (you can create this directory on your book's root directory if it doesn't exist).

Then, on templates/styles/pdf.css you can add the @font-face declaration.

@font-face {
  font-family: "Open Sans Condensed Bold";
  src: url("../../fonts/OpenSans-CondBold.ttf");
}

Finally, to use this font, do something like this:

.chapter > h2 {
  font-family: "Open Sans Condensed Bold";
}

Configuring Markdown

Kitabu uses Redcarpet as the Markdown engine. You can override the default processor by setting Kitabu::Markdown.processor. This can be done by adding something like the following to config/helper.rb:

Kitabu::Markdown.processor = Redcarpet::Markdown.new(
  Kitabu::Markdown::Renderer.new(hard_wrap: false, safe_links_only: true),
  tables: true,
  footnotes: true,
  space_after_headers: true,
  superscript: true,
  highlight: true,
  strikethrough: true,
  autolink: true,
  fenced_code_blocks: true,
  no_intra_emphasis: true
)

The above options are Kitabu's defaults.

References

• Markdown: http://daringfireball.net/projects/markdown/syntax
• Markdown PHP: https://michelf.ca/projects/php-markdown/extra/

Legal Notes

• PrinceXML: license

Alternatives:

• If you're not planning to buy PrinceXML, consider using DocRaptor. Here's how you can easily do it:

curl -H "Content-Type:application/json" -d'{"user_credentials":"YOUR_CREDENTIALS_HERE", "doc":{"name":"kitabu.pdf", "document_type":"pdf", "test":"false", "document_url":"https://dl.dropboxusercontent.com/u/123456789/output/kitabu.pdf.html"}}' http://docraptor.com/docs > kitabu.pdf

Maintainer

• Nando Vieira

Contributors

• https://github.com/fnando/kitabu/contributors

Contributing

For more details about how to contribute, please read https://github.com/fnando/kitabu/blob/main/CONTRIBUTING.md.

License

The gem is available as open source under the terms of the MIT License. A copy of the license can be found at https://github.com/fnando/kitabu/blob/main/LICENSE.md.

Code of Conduct

Everyone interacting in the kitabu project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.