rstudio/rmarkdown v2.12

rmarkdown 2.12

on GitHub

html_document() and html_document_base() gains the math_method argument to support all the math rendering engines from Pandoc: "mathjax", "katex", "mathml", "webtex", and "gladtex". For backward compatibility, the mathjax argument still works and will take precedence over math_method, but we recommend using the new math_method argument instead of the mathjax argument, and the latter could be deprecated in the future.

You can specify a math engine via math_method as an engine name, e.g.,

output:
  html_document:
    math_method: katex

or provide both a name and a URL (for mathjax, katex and webtex):

output:
  html_document:
    math_method: 
      engine: mathjax
      url: https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml-full.js

For math_method = "katex", KaTeX CDN will be inserted in version 0.15.2 by default (from jsdelivr). A custom URL toward another CDN can be passed as url.

For math_method = "webtex", it will default to inset SVG using https://latex.codecogs.com/svg.image?. Use https://latex.codecogs.com/png.image? for PNG. See https://latex.codecogs.com for supported options (dpi, background, ...).

Most HTML output format using html_document() or html_document_base() as based format should benefit from this new feature.
See ?rmarkdown::html_document() for details (thanks, @atusy, #1940).

github_document() also gains the math_method argument set to "webtex" by default so that LaTeX equations can be rendered in the Github Markdown document as images. Previously, LaTeX equations were not rendered. Set math_method = NULL to deactivate.

Added support for katex R package as a math engine with math_method = "r-katex" in HTML documents. This method offers server-side rendering of all the equations, which means no JS processing is needed in the browser as with usual KaTeX or MathJaX methods. (thanks, @jeroen, #2304).

anchor_sections can now be easily customized using style or depth element for anchor_sections. For example:

output:
  html_document:
    anchor_sections:
      style: symbol # use symbol style ("hash", "symbol", "icon")
      depth: 2 # max depth to apply anchor on (default to max which is 6)

Customizing using a CSS rule is still possible. Detailed explanation and examples have been added to the help page ?html_document.

Improved the highlighting mechanism in formats that supports highlight argument:

• It is now possible to pass a custom theme file .theme in highlight argument for customizing the syntax highlighting style used by Pandoc.
• In addition to Pandoc's own supported themes, two more themes are bundled in the package: highlight: arrow a theme optimized for accessibility and color constrast (thanks to @apreshill), and highlight: rstudio to mimic the RStudio editor theme.
• For HTML output only, added optional downlit support in html_document() for R syntax highlighting and autolinking. Use highlight_downlit = TRUE to activate it (same argument as in distill). This features require the downlit package.

Templates for html_document() and ioslides_presentation() gained a new CSS rule to display single line <summary> content inline (rstudio/rstudio#10589).

md_document() gained a new standalone argument, which is FALSE by default unless toc = TRUE. This allows to output authors, date and other metadata per the Pandoc's template. Due to limitation in how Pandoc is handling metadata blocks in its extensions yaml_metadata_block, preserve_yaml = TRUE now deactivate any extension to let rmarkdown directly handle the keeping of YAML block - this means it does not set standalone = TRUE by default. Meanwhile, github_document() gained the preserve_yaml argument (thanks, @florisvdh, #2297).

Added available_templates() to list all the templates from a specific package that can be used with rmarkdown::draft().

Following support in Pandoc 2.15, powerpoint_presentation() gained a incremental argument as other slide formats. As a reminder, setting incremental = TRUE will make lists to display incrementally. See more in Pandoc's MANUAL.

Added support for Pandoc's dir variable in HTML templates. This is the second Language Variables after lang.

Added a global option rmarkdown.html_dependency.header_attr (TRUE by default). It can be set to FALSE to opt-out the HTML dependency html_dependency_header_attrs() in documents based on html_document_base() (thanks, @salim-b rstudio/bookdown#865, @maelle r-lib/downlit#1538).

Rendering using runtime: shiny_prerendered or runtime: shinyrmd now natively supports custom templates. Previously since 2.8, developers had to add a special comment, <!-- HEAD_CONTENT -->, conditionally to shiny-prerendered variable. (See also NEWS from 2.8 for the previous behavior). The new behavior inserts required special comment <!-- HEAD_CONTENT --> as a last element of $header-includes$. If templates rely on the old behavior and require some contents between $header-includes$ and <!-- HEAD_CONTENT -->, consider including them with $header-includes$ (thanks, @atusy, @gadenbuie #2249).

A shiny prerendered document with only a empty server context does not error anymore. Document will be rendered with a empty server function and server.R file will be ignored. To use server.R, no server context should be present in the Rmd document (thanks, @jcheng5, #2305).

Fixed a regression with rendering shiny_prerendered document (thanks, @aronatkins, @gadenbuie, #2218).

Fixed an issue in beamer_presentation() where header-includes would be overwritten by includes = list(in_header =) (thanks, @samcarter, #2294). Same fix as for pdf_document() (#1359).

Fixed broken links to section headers when number_sections = TRUE is specified in md_document and github_document (thanks, @atusy, #2093).

draft() now works with devtools::load_all() and testthat when used in other packages.

Lua Filters: Added two more functions in shared.lua for other package to use:

• Added type() function backward compatible following Pandoc 2.17 changes.
• Added print_debug() for easier logging during debug.