Understanding Bookdown Configuration Options

Bookdown is a popular R package used for authoring documents in R. It allows users to create books, reports, and presentations with ease. One of the key features of bookdown is its ability to generate various output formats from a single document. However, configuring these settings can be overwhelming, especially for beginners. In this article, we will delve into the world of bookdown configuration options, exploring the differences between _bookdown.yml, _output.yml, and YAML headers in the first document.

R Markdown Basics

Before diving into the specifics of bookdown, it’s essential to understand the basics of R Markdown. R Markdown is a variant of Markdown that incorporates R code and output. It allows users to create documents with both text and code using a single file. The resulting document can be rendered in various formats, including HTML, PDF, EPUB, and more.

Bookdown builds upon this foundation, providing a set of tools for authoring books, reports, and presentations. At its core, bookdown is a package that wraps around R Markdown to create a book-like structure from a single document or multiple documents.

YAML Header of the First Document

One common configuration option for bookdown is the YAML header in the first document. This section can contain additional pandoc parameters, which are used to customize the output format of the document.

Required Parameters

The YAML header must contain a specific line: site: bookdown::bookdown_site. This parameter indicates that the document is part of a book created using bookdown.

Additionally, this section may contain multiple output formats specified by the output field. The recommended approach is to list all formats at the top level, rather than under an output field.

Example YAML Header

Here’s an example YAML header that demonstrates how to specify multiple output formats:

---
site: bookdown::bookdown_site
output:
  bookdown::gitbook:
    title: "My Book"
    theme: "default"
  bookdown::pdf_book:
    title: "My PDF Book"
  bookdown::epub_book:
    title: "My EPUB Book"
---

In this example, we specify three output formats: GitBook, PDF Book, and EPUB Book. Each format has its own configuration options, such as title and theme.

_bookdown.yml

The _bookdown.yml file is another configuration option for bookdown. This file contains all parameters used for generating the book and saves the results.

Example _bookdown.yml

Here’s an example _bookdown.yml file that demonstrates how to configure various settings:

---
book_filename: "_book_example"
repo: https://github.com/<user>/<repo>
before_chapter_script: ["script1.R"]
after_chapter_script:  ["script2.R"]
output_dir: "_book"
clean: ["deleteme.Rmd"]
rmd_files: ["index.Rmd", "02-literature.Rmd", "01-intro.Rmd"]
delete_merged_file: true
language:
  label: 
    fig: "FIGURE "
    tab: "TABLE "
  ui:
    edit: "Edit"
    chapter_name: "Chapter "
rmd_subdir: ["content/"]
---

In this example, we specify various settings for the book, including the file name, repository URL, and script files. We also configure output directory, cleaning options, and language settings.

Interchanging Configuration Options

Now that we’ve explored each configuration option in detail, let’s discuss how they can be used interchangeably.

The YAML header of the first document can contain some parameters that are also available in _bookdown.yml. However, not all parameters can be used in both places. The output field in the YAML header is limited to specifying multiple output formats at the top level, while _bookdown.yml offers more flexibility and customization options.

On the other hand, _bookdown.yml contains all parameters that are available in the YAML header, as well as some additional settings like repo and language. However, using _bookdown.yml requires specifying all configuration options upfront, which can be overwhelming for beginners.

Best Practices

So, where should you put your configuration options? The answer lies in best practices. Here are some guidelines to follow:

• Use the YAML header of the first document to specify basic output formats and parameters.
• Use _bookdown.yml to configure more advanced settings, such as repository URLs, script files, and language settings.

In general, it’s recommended to use the YAML header for simple configurations and _bookdown.yml for more complex settings. By following these guidelines, you can avoid confusion and ensure that your book is generated correctly.

Conclusion

Bookdown configuration options can seem daunting at first, but with this guide, you should have a better understanding of how they work together. Remember to use the YAML header of the first document for basic output formats and parameters, and _bookdown.yml for more advanced settings. By following these guidelines, you’ll be well on your way to creating beautifully formatted books, reports, and presentations with bookdown.

Last modified on 2023-09-27