R/make_request.R

In mps9506/aarapir: Access ArcGIS Online Features in R

#' Make a request
#'
#' Right now this works with json files
#'
#' @param url character, the base url
#' @param path character, anything after the url
#' @param args list, named query list
#' @param parse_json logical, probably \code{TRUE}
#' @param img logical, defaults to \code{FALSE}. Needs to be \code{TRUE} if downloading raster.
#' @param ... curl options
#'
#' @return If \code{parse_json = TRUE} returns a list, else returns unparsed text.
#' @export
#' @import crul
#' @importFrom  jsonlite fromJSON
#' @importFrom raster brick
#' @keywords internal
make_request <- function(url,
                         path = NULL,
                         args = list(),
                         parse_json = TRUE,
                         img = FALSE,
                         ...) {
  # create a HttpClient object, defining the url
  cli <- crul::HttpClient$new(url = url,
                              opts = list(...))
  # do a GET request
  if (img == FALSE) {
    res <- cli$get(path = path, query = args)
  }

  else {
    f <- tempfile("ras", fileext = ".tiff")
    res <- cli$get(path = path,
                   query = args,
                   disk = f)
  }

  # check to see if request failed or succeeded
  # - if succeeds this will return nothing and proceeds to next step
  res$raise_for_status()

  if (img == FALSE) {
    # parse response to plain text (JSON in this case) - most likely you'll
    # want UTF-8 encoding
    txt <- res$parse("UTF-8")
    # parse the JSON to an R list
    if (parse_json == TRUE) {
      jsonlite::fromJSON(txt)
    }
    else {
      return(txt)
    }
  }
  else{
    # Read the tiff as raster brick
    # tiff should have crs and extent attched.
    r1 <- raster::brick(f)
    return(r1)

  }

}