R/get_latest_data_file_names.R

In ctsit/rdatil: Useful functions to generate REDCap reports

#' Gets the latest downloaded files (in terms of date) from the provided
#' from_directory, as well as the date reflected in the filenames.
#' If no arguments are provided, the directory is assumed to be the '~/Downloads/' folder.
#'
#' @param from_directory A directory where to find the latest data.
#' @param patterns A key-value pairs vector containing the label and regex pattern.
#' @return A vector containing key-value pairs where the keys are the labels in 'patterns'
#'         and the values are the latest file names according to the patterns.
#' @export
#' @examples
#' dataDict <- 'AnimalIdentification_DataDictionary_2018-07-06.csv'
#' data <- 'AnimalIdentification_Data_2018-07-06_1604.csv'
#' write.csv("", file.path(system.file(), dataDict))
#' write.csv("", file.path(system.file(), data))
#' patterns <- c("data" = "AnimalIdentification_Data_20\\d\\d.*\\.csv",
#' "metadata" = "AnimalIdentification_DataDictionary_20\\d\\d.*\\.csv",
#' "date" = "\\d{4}-\\d{2}-\\d{2}")
#' get_latest_data_file_names(system.file(), patterns)
#' file.remove(c(file.path(system.file(), dataDict), file.path(system.file(), data)))
get_latest_data_file_names <- function(from_directory='~/Downloads/', patterns) {
  find_latest_data <- function(x, dir) head(sort(list.files(path = dir, pattern = x), decreasing=TRUE), n=1)
  file_names <- unlist(lapply(patterns[names(patterns) != 'date'] , FUN=find_latest_data, dir=from_directory))
  date <- stringr::str_extract(file_names[1], patterns['date'])
  file_names <- c(file_names, date)
  names(file_names) <- c(names(patterns[names(patterns) != 'date']), 'date')
  return(file_names)
}