In ropenscilabs/tinkr: Cast '(R)Markdown' Files to 'XML' and Back Again

Only the body of the (R) Markdown file is cast to XML, using the Commonmark specification via the commonmark package. Frontmatter metadata can be stored in the YAML, TOML or JSON format. YAML-formatted metadata could be edited using the yaml package, JSON-formatted metadata could be edited using the jsonlite package. which is not the goal of this package.

We have created an R6 class object called yarn to store the representation of both the frontmatter and the XML data, both of which are accessible through the $body and $frontmatter elements. The field called $frontmatter_format contains the format of the metadata (YAML, TOML, or JSON). In addition, the namespace prefix is set to "md" in the $ns element.

You can perform XPath queries using the $body and $ns elements:

library("tinkr")
library("xml2")
path <- system.file("extdata", "example1.md", package = "tinkr")
head(readLines(path))
ex1 <- tinkr::yarn$new(path)
# find all ropensci.org blog links
xml_find_all(
  x = ex1$body, 
  xpath = ".//md:link[contains(@destination,'ropensci.org/blog')]", 
  ns = ex1$ns
)