-if (require("knitr")) {
- if (packageVersion("knitr") < '1.9.19') {
- stop("knitr must be version 1.9.20 or higher")
- }
-} else stop("knitr 1.9.20 or above is needed to build the lessons.")
+generate_md_episodes <- function() {
-if (!require("stringr"))
- stop("The package stringr is required for generating the lessons.")
+ # avoid ansi color characters from being printed in the output
+ op <- options()
+ on.exit(options(op), add = TRUE)
+ options(crayon.enabled = FALSE)
+ ## get the Rmd file to process from the command line, and generate the path
+ ## for their respective outputs
+ args <- commandArgs(trailingOnly = TRUE)
+ if (!identical(length(args), 2L)) {
+ stop("input and output file must be passed to the script")
+ }
-src_rmd <- list.files(pattern = "??-*.Rmd$", path = "_episodes_rmd", full.names = TRUE)
-dest_md <- file.path("_episodes", gsub("Rmd$", "md", basename(src_rmd)))
+ src_rmd <- args[1]
+ dest_md <- args[2]
-mapply(function(x, y) {
- knitr::knit(x, output = y)
- }, src_rmd, dest_md)
+ ## knit the Rmd into markdown
+ knitr::knit(src_rmd, output = dest_md)
+
+ # Read the generated md files and add comments advising not to edit them
+ add_no_edit_comment <- function(y) {
+ con <- file(y)
+ mdfile <- readLines(con)
+ if (mdfile[1] != "---")
+ stop("Input file does not have a valid header")
+ mdfile <- append(
+ mdfile,
+ "# Please do not edit this file directly; it is auto generated.",
+ after = 1
+ )
+ mdfile <- append(
+ mdfile,
+ paste("# Instead, please edit", basename(y), "in _episodes_rmd/"),
+ after = 2
+ )
+ writeLines(mdfile, con)
+ close(con)
+ return(paste("Warning added to YAML header of", y))
+ }
+
+ vapply(dest_md, add_no_edit_comment, character(1))
+}
+
+generate_md_episodes()