R/durnit.R

In davidsbutcher/durnit: Knit All Documents in a Directory

#' Knit all .Rmd files in a directory.
#'
#' @importFrom magrittr %>%
#'
#' @param input_dir Input directory
#' @param output_dir Output directory
#'
#' @return Knitted documents in the appropriate output format
#'
#' @export
durnit <- function(input_dir, output_dir) {

# Error Checking ----------------------------------------------------------

   if (missing(input_dir)) stop("No input directory provided")

   if (missing(output_dir)) stop("No output directory provided")

   input_dir <- normalizePath(input_dir, winslash = "/")

   output_dir <- normalizePath(output_dir, winslash = "/")

   if (fs::dir_exists(input_dir) == FALSE) stop("Input directory not found")

   if (fs::dir_exists(output_dir) == FALSE) {

      message("\nCreating missing output directory")
      fs::dir_create(output_dir)

   }

   paste("\nRendering all Rmd files in ",
         input_dir, sep = "") %>%
      message

   # Make snapshot -----------------------------------------------------------

   newsnapshot <-
      utils::fileSnapshot(input_dir,
                   recursive = TRUE,
                   file.info = TRUE,
                   md5sum = TRUE,
                   pattern = "\\.Rmd$",
                   ignore.case = TRUE,
                   include.dirs = TRUE,
                   full.names = TRUE)

   # Compare snapshots -------------------------------------------------------

   setwd(output_dir)

   if (fs::file_exists("rmdsnapshot.rds") == TRUE) {

      message("\nLoading snapshot in output directory")

      oldsnapshot <- readRDS("rmdsnapshot.rds")

      message("\nExtracting new/changed Rmd file names")

      rmdlist <-
         utils::changedFiles(oldsnapshot, newsnapshot) %>%
         .[c("changed", "added")] %>%
         unlist() %>%
         normalizePath(winslash = "/") %>%
         as.list()

      dirlist <-
         rmdlist %>%
         purrr::map(~fs::path_rel(.x, start = input_dir)) %>%
         purrr::map(dirname)

      outputlist <-
         rmdlist %>%
         purrr::map(~fs::path_rel(.x, start = input_dir)) %>%
         purrr::map(fs::path_ext_remove) %>%
         purrr::map(~paste(output_dir, ., ".html", sep = ""))

   } else {

      message("\nNO snapshot found! Writing current snapshot to output directory")
      message("Knitting ALL Rmd files in input directory and subdirectories")

      saveRDS(newsnapshot, file = "rmdsnapshot.rds")

      rmdlist <-
         newsnapshot$info %>%
         rownames() %>%
         normalizePath(winslash = "/") %>%
         as.list()

      dirlist <-
         rmdlist %>%
         purrr::map(~fs::path_rel(.x, start = input_dir)) %>%
         purrr::map(dirname)

      outputlist <-
         rmdlist %>%
         purrr::map(~fs::path_rel(.x, start = input_dir)) %>%
         purrr::map(fs::path_ext_remove) %>%
         purrr::map(~paste(output_dir, ., ".html", sep = ""))

   }

   # Check for directories ---------------------------------------------------

   if (length(outputlist) != 0) {

      for (i in seq_along(dirlist)) {

         if (fs::dir_exists(dirlist[[i]]) == FALSE) {

            fs::dir_create(dirlist[[i]])
            message(paste("\nDirectory", dirlist[[i]], "not found, created"))

         } else {

            message(paste("\nDirectory", dirlist[[i]],
                          "found for", basename(outputlist[[i]])))

         }

      }

      # Knit new/changed documents -------------------------------------------

      yamloutput <- rmdlist %>%
         purrr::map(rmarkdown::yaml_front_matter) %>%
         purrr::map(magrittr::extract2, "output") %>%
         purrr::map(names)

      purrr::pwalk(list(rmdlist, outputlist, yamloutput),
                   ~rmarkdown::render(input = ..1,
                                      output_file = ..2,
                                      output_format = ..3))

      # Save the new snapshot at the end, just in case something fails above!

      saveRDS(newsnapshot, file = "rmdsnapshot.rds")

      message("\n\nNew/changed Rmd files knitted to output
directory and new snapshot saved. FINISHED.")

   } else {

      message("\n\nNo new or changed Rmd files in input directory. FINISHED.")

   }

}