R/read_weighting_area.R

In geobr: Download Official Spatial Data Sets of Brazil

#' Download spatial data of census weighting areas
#'
#' @description
#' Data of Census Weighting Areas (area de ponderação) of the Brazilian
#' Population Census
#'
#' @template year
#' @param code_weighting The 7-digit code of a Municipality. If the two-digit code
#' or a two-letter uppercase abbreviation of a state is passed, (e.g. 33 or "RJ")
#' the function will load all weighting areas of that state. If
#' `code_weighting="all"` (the default), all weighting areas of the country are
#' loaded.
#' @template simplified
#' @template output
#' @template showProgress
#' @template cache
#' @template verbose
#'
#' @return An `"sf" "data.frame"` OR an `ArrowObject`
#'
#' @export
#'
#' @examplesIf identical(tolower(Sys.getenv("NOT_CRAN")), "true")
#' # Read specific weighting area at a given year
#' w <- read_weighting_area(
#'   code_weighting = 5201108005004,
#'   year = 2010
#'   )
#'
#' # Read all weighting areas of a state at a given year
#' w <- read_weighting_area(
#'   code_weighting = "DF",
#'   year = 2010
#'   )
#'
#' # Read all weighting areas of a municipality at a given year
#' w <- read_weighting_area(
#'   code_weighting = 5201108,
#'   year = 2010
#'   )
#'
#' # Read all weighting areas of the country at a given year
#' w <- read_weighting_area(
#'   code_weighting = "all",
#'   year = 2010
#'   )
#'
read_weighting_area <- function(year,
                                code_weighting = "all",
                                simplified = TRUE,
                                output = "sf",
                                showProgress = TRUE,
                                cache = TRUE,
                                verbose = TRUE){

  # Get metadata with data url addresses
  temp_meta <- select_metadata(
    geography = "weightingareas",
    year = year,
    simplified = simplified
    )

  # check if download failed
  if (is.null(temp_meta)) { return(invisible(NULL)) }


  # download file and open arrow dataset
  temp_arrw <- download_parquet(
    filename_to_download = temp_meta$file_name,
    showProgress = showProgress,
    cache = cache
  )

  # check if download failed
  if (is.null(temp_arrw)) { return(invisible(NULL)) }

  # FILTER
  temp_arrw <- filter_arrw(temp_arrw, code = code_weighting)

  # convert to sf
  temp <- convert_output(temp_arrw, output)

  return(temp)

}