R/chk_file.R

In agapiospanos/StartStopp: START and STOPP criteria evaluation for potentially inappropriate prescribing

#' Helper function to choose the excel file that will provide the data
#'
#' @param path (Character) the path that the excel file can be read from or null in case the user wants to have a file choose window displayed.
#' @return the path that the user chose
#'
#' @author
#' Agapios Panos <panosagapios@gmail.com>
#'
#' @importFrom tools file_ext

chk_file <- function(path){
  if (any(is.null(path), is.na(path), !is.character(path))) {
    path <- choose_file()
  } else if (!file.exists(path)) { # we have to check if exists after passing the check for NULL OR NA as it produces errors if we check exists(NULL) or exists(NA)
    path <- choose_file()
  }
  return(path)
}

choose_file <- function(){
  path <- file.choose();
  if (is.na(path))
    stop("You did not choose an xlsx file to get data from. Rerun the command and choose a file")
  if (file_ext(path) != 'xlsx' & file_ext(path) != 'xls')
    stop("You must choose an xlsx or xls file")
  return(path)
}