R/get_new_additions.R

In one-acre-fund/arc2weather: Downloads and Extracts ARC2 Weather Data

#' creates list of new files to be downloaded, difference between available and current
#'
#' @param existingList files we've already downloaded
#' @param fullList full list of files available on FTP
#' @param directory where to find the current files and where to save data
#' @return A vector of the file names to download


get_new_additions <- function(existingList, fullList, dir){
  # input: list of current data we've accessed
  # what it does: saves list so we have record of what we've accessed
  # output: list of new files we need to access

  updatedList = as.data.frame(fullList[!fullList$V1 %in% existingList$V1,])
  names(updatedList) = "V1"

  directory <- set_list_directory(dir)

  # this saves the list for next time
  saveRDS(updatedList, file = paste(directory, paste("files_downloaded_", todayDate(), ".rds", sep = ""), sep = "/"))


  return(updatedList)

}