Description
Markdown Reference Manuals.
Description
Native R only allows PDF exports of reference manuals. The 'Rd2md' package converts the package documentation files into markdown files and combines them into a markdown version of the package reference manual.
README.md
Installation
To install the Rd2md
package, you can either use the official CRAN repository or install directly from github.
From CRAN:
install.packages("Rd2md")
From Github:
devtools::install_github("quantsch/Rd2md")
The package does not have any third-party package dependencies as I wanted to keep things simple. However, it heavily borrows ideas and code from pkgdown, so big thanks to the great work there!
Introduction
See the introduction vignette:
vignette("introduction")
Roadmap
- significantly expand and improve unit tests
- fail early: introduce input validations for exposed functions
- add header content in output_format to pass
date_format
, etc. - toc "<\!-- toc -->\n\n" and a front_matter implementation for markdown
Extension
You can "easily" extend the parsing functionality by implementing your own parser. Without further details, an (almost) minimal example for text reference manual:
# required: a generic parsing function
as_txt <- function(x, ...) UseMethod("as_txt")
# required: introduces recursion
process_txt_contents <- function(x, ...) {
# traverse through list and concatenate to string
if (is.list(x)) x[] <- lapply(x, as_txt, ...)
paste(as.character(x), collapse = "")
}
# required: a fallback as not all tags might have an `as_txt` method
as_txt.default <- function(x, ...) {
process_txt_contents(x, ...)
}
# not required but improves output significantly:
# we add a section title and a separator for readability
as_txt.rdsection <- function(x, ...) {
paste0(
Rd2md:::tag_to_title(x),
"\n----------------\n\n",
process_txt_contents(x, ...), "\n\n"
)
}
# not required but improves output significantly:
# we add a paragraph after the description file
as_txt.DESCRIPTION <- function(x, ...) paste0(x, "\n\n")
# not required but looks better: we drop the comments
as_txt.COMMENT <- function(x, ...) ""
# required: the output_format definition
txt_document <- function() output_format("txt", ".txt", as_txt)
# now we can render our new text refman:
render_refman(output_format = txt_document())