R/load_scripts.R

In reconhub/rfextras: Extra Functionalities for reportfactory

#' Load R scripts within factory folder
#'
#' This helper function will load all `.R` scripts within a specified factory
#' and folder. All scripts are loaded within the calling environment and in
#' alphanumeric order.
#'
#' @param factory The path to the report factory or a folder within the desired
#'   factory. Defaults to the current directory.
#' 
#' @param folder The folder (relative to the factory) from which to source `.R`
#'   files; defaults to `scripts/`.
#' 
#' @param quiet A logical indicating whether messages should be displayed to the
#'   console (`TRUE`, default), or not.
#'
#' @export
#'
#' @examples
#'
#' if (require(reportfactory)) {
#' 
#' # create factory
#' f <- new_factory(path = tempdir(), move_in = FALSE)
#' 
#' # create .R files in scripts/
#' 
#' ## scripts are loaded in alphanumeric order, so "b.R" is loaded after "a.R" and
#' ## can use its content
#' 
#' cat("addone <- function(x) x + 1", file = file.path(f, "scripts", "addone.R"))
#' cat("a <- 2L", file = file.path(f, "scripts", "a.R"))
#' cat("b <- 2L + a", file = file.path(f, "scripts", "b.R"))
#'
#' ## load scripts, check that 'a', 'b', and 'addone' exist
#' load_scripts(f)
#' a
#' b
#' addone(10)
#' addone(c(a, b))
#' 
#' # cleanup
#' unlink(f, recursive = TRUE)
#' }

load_scripts <- function(factory = ".", folder = "scripts", quiet = FALSE) {

  ## Approach: we list all .R files in the specified folder, and load all of
  ## them in alphanumeric order; we need to make sure all objects are loaded in
  ## the parent environment. This is achieved using `sys.source` rather than
  ## `source`.

  # get the factory root and the script directory
  tmp <- reportfactory::validate_factory(factory)
  root <- tmp$root
  scripts_dir <- file.path(root, folder)

  # check the directory exists
  if(!dir.exists(scripts_dir)) {
    stop(sprintf("directory %s does not exist", scripts_dir))
  }

  ## get parent environment
  parent <- parent.frame()

  ## process .R files in the scripts folder
  script_files <- list.files(
    scripts_dir,
    pattern = "\\.[rR]$",
    recursive = TRUE,
    full.names = TRUE
  )

  script_files <- sort(script_files)

  if (length(script_files)) {
    for (file in script_files) {
        if (!quiet) {
            msg <- sprintf("Loading file: %s", file)
            message(msg)
        }
        sys.source(file, envir = parent)
    }
  } else {
      if (!quiet) {
          message("No `.R` files in %s", scripts_dir)
      }
  }

  ## nothing to return, bye everyone
  return(invisible(NULL))
}