R/editWebFile.R

In dtkaplan/dcfunctions: Functions Used in the Data Computing book and exercises

#' Display a file from the web in the editor
#'
#' Reads a text file from the web and opens the contents in an editor.
#' This is useful, for instance, for sharing assignment templates with students.
#' You MUST "save as" the editor buffer in your own folder
#' if you want to keep it.
#'
#' @return The temporary file name, invisibly.
#' @param url URL locating the file on the web
#' @examples \dontrun{
#'    editWebFile("www.mosaic-web.org/go/datasets/angle.R")
#' }
#' @export
editWebFile <- function(url){

  fname <- basename(url)
  partsOfName <- stringr::str_match_all("our_file_today.html",
                                        "(^.+)(\\.(Rmd|r|R|md|tex|.{1,4})$)")
  filename <- unlist(partsOfName)[2]
  extension <- unlist(partsOfName)[3]
  tmpname <- tempfile(pattern=paste0(filename,"---"), fileext=extension)
  download.file(url, dest = tmpname)
  file.edit(tmpname, title = filename)
  message("Remember to save as ",
          paste0(filename,extension),
          " in your own folder. Until you do, it's just temporary.")
  invisible(tmpname)
}