Release knitr 1.30 · yihui/knitr

NEW FEATURES

Added knitr::hooks_*() functions to get a list of output hooks for a specific format. Previously, these hooks only exist inside the knitr::render_*() functions, and users do not have direct access to them. Now they can be accessed directly, e.g., via knitr::hooks_markdown() to get a list of output hooks for R Markdown documents. You can also set the output hooks individually, e.g., knitr::knit_hooks$set(knitr::hooks_markdown()['source']) only sets the source ouput hook. See more on output hooks at https://yihui.org/knitr/hooks/#output-hooks and https://bookdown.org/yihui/rmarkdown-cookbook/output-hooks.html (thanks, @cderv, #1889).
Added an argument lib.loc to knitr::write_bib().

The option fig_caption = FALSE for rmarkdown::html_document() was unable to suppress the figure captions in some cases.
The internal function fix_options() should be called after option hooks are executed (thanks, @atusy, #1876 and #1877).
When the option options(OutDec = ) is set to a value other than ".", percentages in the chunk options out.width and out.height do not work (thanks, @omgitsmoe, #1887).

knitr::write_bib() removes pairs of single quotes in the titles of citation entries now.
knitr::write_bib() uses the URL in the package DESCRIPTION if it is provided, instead of the canonical CRAN URL for the package.
hook_pdfcrop() and plot_crop() will work only when both programs pdfcrop and ghostscript have been installed. Previously only pdfcrop was checked (thanks, @dalupus, #954).