R/readxl_online.R

In BrookingsInstitution/metro-data-warehouse: Brookings Metro Data Analysis Tools

#' Read excel files from online locations
#'
#' This function loads xls or zipped xls file from online locations. I
#' @param type .xlsx, .xls or .zip
#' @param url Path to the file
#' @return A dataframe
#' @export

readxl_online <- function(url, type = NULL, ...) {
  test <- stringr::str_detect(url, "[.]xls|[.]zip")
  if (test == FALSE) {
    print(message("Expecting file extension of type .xlsx, .xls or .zip. Check the URL or the data source for the correct file extension and use the type argument"))
  }
  # test for individual file extensions for xls use look forward, xls not
  # followed by x
  t1 <- stringr::str_detect(url, "[.]xlsx")
  t2 <- stringr::str_detect(url, "[.]xls(?!x)")
  tz <- stringr::str_detect(url, "[.]zip")
  if (t1 == TRUE) {
    type = ".xlsx"
  }
  if (t2 == TRUE) {
    type = ".xls"
  }
  if (tz == TRUE) {
    httr::GET(url, httr::write_disk("tmp.zip", overwrite = TRUE))
    tmp <- unzip("tmp.zip")
    # On osx more than one file name is returned, select first element.
    df <- readxl::read_excel(tmp[[1]],...)
    return(df)
  }
  if (!is.null(type)) {
    type = type

  }
  df <- httr::GET(url, httr::write_disk(paste0("tmp", type), overwrite = TRUE))
  df <- readxl::read_excel(paste0("tmp", type),...)


}