NEW FEATURES

• This version has included a new RStudio template project to start an HTML book in bookdown::gitbook or bookdown::bs4_book. Template projects can be created using the RStudio IDE menu "New Project", or using one of the two new functions, create_gitbook() or create_bs4_book(), to easily create the template that you want to start with from within the R console (#225, #1123, #1201).

• Added an argument global_numbering to most output format functions in this package to control the figure/table numbering scheme (thanks, @elfunesto #948, @Kodiologist #1057). If TRUE, number figures and tables globally throughout a document (e.g., Figure 1, Figure 2, ...). If FALSE, number them sequentially within sections (e.g., Figure 1.1, Figure 1.2, ..., Figure 5.1, Figure 5.2, ...). Previously, this numbering scheme was hard-coded internally according to the number_sections argument (global_numbering = !number_sections). Now the two arguments have become independent, e.g., you can use global_numbering = TRUE with number_sections = TRUE.

• For HTML book formats, a default 404.html page will now be created if none exists already. This page can be customized by adding a _404.md or _404.Rmd file which will be rendered to HTML and inserted in the book. Most web serving platforms (e.g. Netlify, GH Pages, etc.) will use this file named 404.html in the root as a custom error page. Otherwise, like browsers do, a default 404 page is shown. For context, a 404 error indicates that the file can’t be found, and it happens when a browser can’t find a requested web page. This could happen with your online book if you shared a link to a section but change the name of this section leading to a change in url (#1035).

• The bookdown::gitbook output format now supports an alternative search engine, namely fuse.js, which has several advantages over lunr.js, the previous search engine for gitbook. Using fuse.js will fix a number of long-standing issues such as #734, #735, and #792. To enable fuse.js, set the search engine to be fuse in gitbook's config in YAML, e.g.,

  output:
    bookdown::gitbook:
      config:
        search:
          engine: fuse

  Depending on user feedback, we may set fuse to be the default search engine in a future version of bookdown. We will appreciate your testing and feedback!

• bs4_book(splib_bib = TRUE) can now be specified to have the same effect as in gitbook(). References will be shown at the end of each chapter and not only at the end of the book. This is useful with bs4_book() when a citation style not supporting footnotes is used because in that case, references are not shown inline in popups (thanks, @shirdekel, #1185).

• In bs4_book(), improvement regarding copy button:

  • It has now a light icon instead of a text with white background (#1192).
  • It will no more show on output block code when knitr's option is collapse = FALSE (#1197).
  • It will now be placed correctly on the right side of the code block, with a light color which gets darker on hover so that it is less obtrusive when overlapping text in block with long lines (#1204). If you want to customize part of the UI to change this default behavior, you can do it using a custom css with bs4_book().

• In bs4_book(), copy button has now a light icon instead of a text with white background (#1192).

• bs4_book() has now some <meta> tags that allows sharing a published book on social media. cover-image, url, title and description set in YAML will be used in index.html and then modified to be adapted per HTML page (#1034).

• repo specification in bs4_book() can now be done in a more flexible way: base url, branch name, subdir and icon can be specify. See ?bookdown::bs4_book() for details (thanks, @maelle, #1036).

• epub_version argument in epub_book() can now be set to epub2 to create EPUB book of version 2. This follows an old change for default behavior in Pandoc 2.0 where the alias epub defaults to epub3 and no more epub2 (thanks, @jtbayly, #1150).

• Theorem and Proof environment can now be used with beamer_presentation2() using fenced Div syntax like this

  ::: {.theorem #label name="My Theorem"}
  Content
  :::

  However, as beamer defines its own LaTeX theorem environments, bookdown won't add any definition in preamble as it is doing with pdf_book(). This means user will have to define the ones supported by bookdown and not yet defined by beamer. Special environment from beamer (like fact) needs to be used with usual Custom Blocks syntax. See related issues for examples in their discussions thread (thanks, @XiangyunHuang, #1143, #1145).

  This change comes with several small improvements in custom-enviromnent.lua for latex and beamer format, including a new option bookdown.theorem.preamble to opt-out bookdown addition of theorems and proofs definitions in LaTeX preamble. Set it to FALSE if you have conflict with some specific format for example (like #1001).

MINOR CHANGES

• Updated the jQuery library to v3.x, which is now imported from the R package jquerylib (thanks, @mterente #693, @cooknl #882).

BUG FIXES

• Removed the requirement for .html filenames to be alphanumeric, which fixes a common error "Automatically generated filenames contain duplicated ones: -" (thanks, @psychelzh #605, @AzureRabbit #902, @carloslederman #1000, Ritsu Kitagawa https://stackoverflow.com/q/60014350/559676, Shrek Tan).

• Fix an issue with bookdown_site() where the comment in site: line key was not supported (thanks, @LDSamson, #1194).

• Figure reference links now point correctly to the top of figures (thanks, @GuillaumeBiessy, #1155).

• When the site field is quoted in index.Rmd's YAML data (i.e., site: "bookdown::bookdown_site"), bookdown fails to identify the root directory of the book (thanks, @dchiu911, #1160).

• The figure/table labels are no longer duplicated in Word output generated from Pandoc 2.14.1 (thanks, @dewittpe, #1223).

• When a book has multiple authors, the CSS styles for each author were inlined in the <p> tags, and hence are hard to override. Now the class multi-author is applied to each individual author's <p> tag, and the CSS rules are defined on this class instead (thanks, @robjhyndman, #1170).

• Style change in bs4_book() where code block inside callout blocks will have their background fill the whole width of the bordered block (#1175).

• In bs4_book(), math in footnotes is now rendered (@mine-cetinkaya-rundel, #1026)

• Fix an issue with bs4_book() where text written using Line Block was not found in search (thanks, @dmklotz, #1141).