R/import.R

In epiCleanr: A Tidy Solution for Epidemiological Data

#' Import Data from Various File Formats
#'
#' This function provides a unified interface for importing data from various
#' file formats supported by the \code{\link[=rio]{rio}} package. The format is
#' automatically detected from the file extension to simplify the importing
#' process.
#'
#' @param file_path Character string specifying the path to the input file or
#'   a URL pointing to the dataset.
#' @param ... Additional arguments to be passed to the underlying read
#'   functions. These arguments are specific to the file format being imported.
#'   Please refer to the documentation of each package used for more
#'   information.
#'
#' @return A data frame or appropriate R object containing the imported data.
#'
#' @examples
#' # Locate test data directory
#' path <-  system.file("extdata",
#'                      package = "epiCleanr")
#'
#' # Import a CSV file
#' data_csv <- import(file_path = file.path(path, "test_data.csv"))
#'
#' # Import an Excel file
#' data_excel <- import(file_path = file.path(path, "test_data.xlsx"))
#'
#' # Import a Stata DTA file
#' data_dta <- import(file_path = file.path(path, "test_data.dta"))
#'
#' # Import an RDS file
#' data_rds <- import(file_path = file.path(path, "test_data.rds"))
#'
#' # Import an RData file
#' data_rdata <- import(file_path = file.path(path, "test_data.RData"))
#'
#' # Import an SPSS file
#' data_spss <- import(file_path = file.path(path, "test_data.sav"))
#'
#' @seealso \code{\link[=rio]{rio::import()}},  which this function is based on.
#'
#' @importFrom rio import
#' @importFrom rio install_formats
#' @importFrom tools file_ext
#' @importFrom withr with_options
#'
#' @export
import <- function(file_path, ...) {

  # Check if the input file path is a URL and if so, read from URL directly
  if (grepl("^http[s]?://", file_path, ignore.case = TRUE)) {
    return(rio::import(file_path, ...))
  }

  # Extract the file extension from the input file path
  file_ext <- tools::file_ext(file_path)

  # List of supported formats
  supported_formats <- c(
    "csv", "tsv", "txt", "csvy", "sas7bdat", "sav",
    "dta", "xpt", "xlsx", "RData", "rds", "tsv"
  )

  # If there is no file extension
  if (file_ext == "") {
    stop(paste("The provided file has no extension.",
               "Please specify a file with a valid extension."))
  }

  # If the file extension is unsupported
  if (file_ext %in% supported_formats) {
    return(rio::import(file_path, ...))
  } else {
    stop(
      paste0(
        "File format '", file_ext, "' not supported by 'rio'. ",
        "Please refer to the package documentation for a full list",
        "of supported formats."
      )
    )
  }
}