generate_md_episodes <- function() {
- library("methods")
-
- if (require("knitr") && packageVersion("knitr") < '1.9.19')
- stop("knitr must be version 1.9.20 or higher")
+ # 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")
+ }
- if (!require("stringr"))
- stop("The package stringr is required for generating the lessons.")
+ src_rmd <- args[1]
+ dest_md <- args[2]
- if (require("checkpoint") && packageVersion("checkpoint") >= '0.4.0') {
- required_pkgs <-
- checkpoint:::scanForPackages(project = "_episodes_rmd",
- verbose=FALSE, use.knitr = TRUE)$pkgs
- } else {
- stop("The checkpoint package (>= 0.4.0) is required to build the lessons.")
- }
+ ## knit the Rmd into markdown
+ knitr::knit(src_rmd, output = dest_md)
- missing_pkgs <- required_pkgs[!(required_pkgs %in% rownames(installed.packages()))]
+ # Read the generated md files and add comments advising not to edit them
+ add_no_edit_comment <- function(y) {
+ con <- file(y)
+ mdfile <- readLines(con)
+ if (mdfile[1] != "---")
+ stop("Input file does not have a valid header")
+ mdfile <- append(
+ mdfile,
+ "# Please do not edit this file directly; it is auto generated.",
+ after = 1
+ )
+ mdfile <- append(
+ mdfile,
+ paste("# Instead, please edit", basename(y), "in _episodes_rmd/"),
+ after = 2
+ )
+ writeLines(mdfile, con)
+ close(con)
+ return(paste("Warning added to YAML header of", y))
+ }
- if (length(missing_pkgs)) {
- message("Installing missing required packages: ",
- paste(missing_pkgs, collapse=", "))
- install.packages(missing_pkgs)
- }
-
- ## find all the Rmd files, and generate the paths for their respective outputs
- src_rmd <- list.files(pattern = "??-*.Rmd$", path = "_episodes_rmd", full.names = TRUE)
- dest_md <- file.path("_episodes", gsub("Rmd$", "md", basename(src_rmd)))
-
- ## knit the Rmd into markdown
- mapply(function(x, y) {
- knitr::knit(x, output = y)
- }, src_rmd, dest_md)
-
- # Read the generated md files and add comments advising not to edit them
- vapply(dest_md, 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))
- },
- character(1))
+ vapply(dest_md, add_no_edit_comment, character(1))
}
generate_md_episodes()