# kitabu [![Tests](https://github.com/fnando/kitabu/workflows/ruby-tests/badge.svg)](https://github.com/fnando/kitabu) [![Gem](https://img.shields.io/gem/v/kitabu.svg)](https://rubygems.org/gems/kitabu) [![Gem](https://img.shields.io/gem/dt/kitabu.svg)](https://rubygems.org/gems/kitabu) [![MIT License](https://img.shields.io/:License-MIT-blue.svg)](https://tldrlegal.com/license/mit-license) 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 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](http://docraptor.com), which have plans starting at \$15/mo. ## Features - Write using Markdown - Book layout support - Syntax highlight - Generate HTML, PDF, e-Pub (version 3.3), 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 ├── assets │   ├── fonts │   ├── images │   │   ├── cover.png │   │   ├── kitabu.svg │   │   ├── markdown.svg │   │   └── up.svg │   ├── scripts │   └── styles │   ├── epub.css │   ├── html.css │   ├── pdf.css │   ├── print.css │   └── support │   ├── kitabu.css │   ├── normalize.css │   ├── notes.css │   └── toc.css ├── config │   ├── helpers.rb │   ├── kitabu.yml │   └── locales │   └── en.yml ├── templates │   ├── epub │   │   ├── cover.erb │   │   ├── page.erb │   │   └── toc.erb │   └── html │   └── layout.erb └── text ├── 01_Getting_Started.md ├── 02_Creating_Chapters.md ├── 03_Syntax_Highlighting.md.erb ├── 04_Dynamic_Content.md.erb ├── 05_Exporting_Files.md └── 06_Changelog.md 13 directories, 28 files ``` 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! ![Kitabu - Sample Book](https://github.com/fnando/kitabu/raw/main/attachments/cover.png) There's a generated sample available on the [attachments directory](https://github.com/fnando/kitabu/tree/main/attachments) • [PDF](https://github.com/fnando/kitabu/raw/main/attachments/kitabu.pdf) / [EPUB](https://github.com/fnando/kitabu/raw/main/attachments/kitabu.epub) / [MOBI](https://github.com/fnando/kitabu/raw/main/attachments/kitabu.mobi) / [HTML](https://github.com/fnando/kitabu/raw/main/attachments/browser-version.png). 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 h1-h6 tags. To print the TOC, you need to print a variable called `toc`, using the eRb tag. <%= toc %> #### Frontmatter Markdown files (and their `.md.erb` counterparts) support frontmatter, a section that can inject variables to the page. Notice that the contents inside the `---` delimiters must be valid YAML annotation and only basic types can be used (booleans, numbers, strings, nils and hashes/arrays with these same types). Right now there's only one special value called `section`, which defines the class section when generating files. This allows you to have files inside your `text` directory that doesn't necessarily should have styling like regular chapters. For instance, this is how you can define a changelog section: ```markdown --- section: changelog --- ## Changelog ### Jan 26, 2024 - Initial release ``` > [!NOTE] > > Notice that `section` will be retrieved from the first file, even if you have > multiple files defining a section with a directory. This meta data will be inject on your template using the variable `meta`. If you have other variables, you could print them as `<%= meta["varname"] %>`. ### Using ERB You can also have `.md.erb` files. You can mix Markdown and HTML, like the following: ## This the chapter title <%= image_tag "myimage.png" %> The above content must be placed in a `.md.erb` file. The generated content will be something like this: ```html ``` You book's helpers can be added to `config/helpers.rb`, as this file is loaded automatically by kitabu. You can see available helpers on . ### 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_line=1&line_numbers=1 echo "Hello World"; ``` - We use [Redcarpet](https://rubygems.org/gems/redcarpet) for Markdown processing. - We use [Rouge](https://rubygems.org/gems/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` ### Hooks There are a few hooks that allows manipulating the content. You can use `before_render` and `after_render` to process the Markdown content. You can add such hooks to your `config/helpers.rb` file. ```ruby Kitabu::Markdown.add_hook(:before_render) do |content| # manipulate content and return it. content end Kitabu::Markdown.add_hook(:after_render) do |content| # manipulate content and return it. content end ``` ### Using custom fonts You can use custom fonts on your ebooks. 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 `assets/styles/support/fonts.css` you can add the `@font-face` declaration. ```css @font-face { font-family: "Open Sans Condensed Bold"; src: url("../../fonts/OpenSans-CondBold.ttf"); } ``` Finally, to use this font, do something like this: ```css .chapter > h1 { font-family: "Open Sans Condensed Bold"; } ``` Instead of doing the above manually, you can also use Prince's `--scanfonts` option. ```console $ prince --scanfonts assets/fonts/* > assets/styles/support/fonts.css ``` Just remember to replace the generated path to be something like `../../fonts` instead. > [!TIP] > > In most cases, it's easier to redefine `sans-serif`, `serif` and `monospace` > fonts. To know more about how to do this, read Prince's > [Redefining the generic font families](https://www.princexml.com/doc/styling/#redefining-the-generic-font-families) > documentation. If you're unsure if fonts are actually being used on PDF files, use the environment variable `PRINCEOPT` to disable system fonts. ```console $ PRINCEOPT='--no-system-fonts --debug --log output/prince.log' kitabu export --only pdf => e-book couldn't be exported $ tail -n10 output/prince.log Sat Jan 27 18:39:10 2024: debug: font request: Caslon, serif Sat Jan 27 18:39:10 2024: warning: Ensure fonts are available on the system or load them via a @font-face rule. Sat Jan 27 18:39:10 2024: warning: For more information see: Sat Jan 27 18:39:10 2024: warning: https://www.princexml.com/doc/help-install/#missing-glyphs-or-fonts Sat Jan 27 18:39:10 2024: internal error: Unable to find any available fonts. Sat Jan 27 18:39:10 2024: finished: failure Sat Jan 27 18:39:10 2024: ---- end ``` ### Configuring Markdown Kitabu uses [Redcarpet](https://github.com/vmg/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/helpers.rb`: ```ruby 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. ### Exporting PDFs using DocRaptor If you're not planning to buy PrinceXML, consider using [DocRaptor](http://docraptor.com). Here's how you can easily do it: ```bash curl -H "Content-Type:application/json" -d'{"user_credentials":"YOUR_CREDENTIALS_HERE", "doc":{"name":"kitabu.pdf", "document_type":"pdf", "test":"false", "document_url":"https://example.com/output/kitabu.pdf.html"}}' http://docraptor.com/docs > kitabu.pdf ``` ## References - Markdown: - Markdown PHP: - Some PrinceXML tips by the creator himself: ## Legal Notes - PrinceXML: [license](http://www.princexml.com/license/) ## Maintainer - [Nando Vieira](https://github.com/fnando) ## 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](https://opensource.org/licenses/MIT). 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](https://github.com/fnando/kitabu/blob/main/CODE_OF_CONDUCT.md).