knitr 1.22

NEW FEATURES

• Added chunk options class.error, class.warning, and class.message to customize the CSS classes for errors, warnings, and messages in R Markdown output, respectively (thanks, @gadenbuie, #1676).

• Added a new engine sass/scss to convert Sass/SCSS to CSS using either the sass R package (LibSass) or Dart Sass executable (when R package not found, the engine option engine.opts = list(package = FALSE), or engine.path to executable is provided). After conversion, resulting CSS is treated as in the CSS engine (thanks, @emilyriederer, #1666).

• The cat engine supports the chunk option eval = FALSE now (thanks, @HanOostdijk, #1618).

• The chunk option out.extra can be used to include extra attributes for the <iframe> generated from knitr::include_url() or knitr::include_app() (thanks, @jvcasillas, #1648).

BUG FIXES

• knit_meta_add() could exhaust the system's memory because of a wrong method of vectorization (thanks, @kevinushey @nikkoc, rstudio/rmarkdown#1538).

• The output path should be quoted in pandoc() (thanks, @antoine-sachet, #1644).

• When there are multiple figures with multiple captions in a code chunk, bookdown's figure numbering is incorrect (thanks, Catherine Peng, https://stackoverflow.com/q/53880195/559676).

• Added an argument label to kable() so that users can manually specify a label (thanks, @Inferrator, #1655).

• The chunk option fig.show='hide' doesn't work for knitr::include_graphics() (thanks, @vincentarelbundock, #1675).

• The tikz engine doesn't work on Windows (thanks, Andry, https://stackoverflow.com/q/54839403/559676).

• kable() now generates a table for R Markdown documents even when the data has 0 rows (thanks, @yutannihilation, #1677).

• The chunk options dev = 'tikz' and external = FALSE didn't work in R Markdown (thanks, @martinschmelzer, #1649).

MAJOR CHANGES

• knitr::knit() starts to warn against non-UTF8 encodings (Why?). In the future, we will only support UTF-8 input. If your input file is not encoded in UTF-8, we strongly recommend that you re-save it with UTF-8.

• Removed the encoding arguments in knitr::pandoc(), knitr::knit2pdf(), knitr2wp(), and knitr::Sweave2knitr(). The input files must be encoded in UTF-8.

• knitr::knit2html() still has the encoding argument, but it only supports UTF-8 internally.

MINOR CHANGES

• Changed tools::texi2dvi() to tinytex::latexmk() for the tikz engine to compile TikZ graphics to other foramts (e.g., svg or png). This requires the tinytex package >= v0.10.10: https://github.com/yihui/tinytex.

• Empty lines are no longer removed in the output of purl() (thanks, Marius Hofert).