R/read_package.R

In frictionlessdata/frictionless-r: Read and Write Frictionless Data Packages

#' Read a Data Package descriptor file (`datapackage.json`)
#'
#' Reads information from a `datapackage.json` file, i.e. the [descriptor](
#' https://specs.frictionlessdata.io/data-package/#descriptor) file that
#' describes the Data Package metadata and its Data Resources.
#'
#' See `vignette("data-package")` to learn how this function implements the
#' Data Package standard.
#'
#' @param file Path or URL to a `datapackage.json` file.
#' @return A Data Package object, see [create_package()].
#' @family read functions
#' @export
#' @examples
#' # Read a datapackage.json file
#' package <- read_package(
#'   system.file("extdata", "v1", "datapackage.json", package = "frictionless")
#' )
#'
#' package
#'
#' # Access the Data Package properties
#' package$name
#' package$created
read_package <- function(file = "datapackage.json") {
  # Read file
  if (!is.character(file)) {
    cli::cli_abort(
      "{.arg file} must be a path or URL to a {.file datapackage.json} file.",
      class = "frictionless_error_file_invalid"
    )
  }
  descriptor <- read_descriptor(file, safe = FALSE)

  # Warn if resources is absent
  if (length(descriptor$resources) == 0) {
    cli::cli_warn(
      c(
        "{.arg file} {.file {file}} should have a {.field resources} property
         containing at least one resource.",
        "i" = "Use {.fun add_resource} to add resources."
      ),
      class = "frictionless_warning_file_without_resources"
    )
  }

  # Add directory
  descriptor$directory <- dirname(file) # Also works for URLs

  # Create package
  create_package(descriptor)
}