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

Inserting new nodes into the AST is surprisingly difficult if there is a default namespace, so we have provided a method in the yarn object that will take plain Markdown and translate it to XML nodes and insert them into the document for you. For example, you can add a new code block:

path <- system.file("extdata", "example2.Rmd", package = "tinkr")
rmd <- tinkr::yarn$new(path)
xml2::xml_find_first(rmd$body, ".//md:code_block", rmd$ns)
new_code <- c(
  "```r",
  "message(\"this is a new chunk from {tinkr}\")",
  "```")
new_table <- data.frame(
  package = c("xml2", "xslt", "commonmark", "tinkr"),
  cool = TRUE
)
# Add chunk into document after the first chunk
rmd$add_md(new_code, where = 1L)
# Add a table after the second chunk:
rmd$add_md(knitr::kable(new_table), where = 2L)
# show the first 21 lines of modified document
rmd$head(21)