R/get_parlperiod_presidency.R

In stortingscrape: Access Data from the Norwegian Parliament API

#' Get list of presidency in a given parliamentary period
#' 
#' @description A function for retrieving the presidency for a given parliamentary period from the parliament API.
#' 
#' @usage get_parlperiod_presidency(periodid = NA, good_manners = 0)
#' 
#' @param periodid Character string indicating the id of the parliamentary period to retrieve.
#' @param good_manners Integer. Seconds delay between calls when making multiple calls to the same function
#' 
#' @return A data.frame with the following variables:
#' 
#'    |                   |                                        |
#'    |:------------------|:---------------------------------------|
#'    | **response_date** | Date of data retrieval                 |
#'    | **version**       | Data version from the API              |
#'    | **last_name**     | Last name of presidency member         |
#'    | **first_name**    | First name of presidency member        |
#'    | **from_date**     | Presidency member from date            |
#'    | **party_id**      | Party affiliation of presidency member |
#'    | **person_id**     | Id of the presidency member            |
#'    | **to_date**       | Presidency member to date              |
#'    | **position**      | Presidency position                    |
#' 
#' @seealso [get_mp] [get_mp_bio]
#' 
#' 
#' @examples
#' \dontrun{
#'  
#' # Request one MP by id
#' get_parlperiod_presidency("2005-2009")
#' 
#' }
#' 
#' @import rvest httr2
#' @export
#' 
get_parlperiod_presidency <- function(periodid = NA, good_manners = 0){
  
  url <- paste0("https://data.stortinget.no/eksport/presidentskapet?stortingsperiodeid=", periodid)
  
  base <- request(url)
  
  resp <- base |> 
    req_error(is_error = function(resp) FALSE) |> 
    req_perform()
  
  if(resp$status_code != 200) {
    stop(
      paste0(
        "Response of ", 
        url, 
        " is '", 
        resp |> resp_status_desc(),
        "' (",
        resp$status_code,
        ")."
      ), 
      call. = FALSE)
  }
  
  if(resp_content_type(resp) != "text/xml") {
    stop(
      paste0(
        "Response of ", 
        url, 
        " returned as '", 
        resp_content_type(resp), 
        "'.",
        " Should be 'text/xml'."), 
      call. = FALSE) 
  }
  
  tmp <- resp |> 
    resp_body_html(check_type = FALSE, encoding = "utf-8") 
  
  tmp <- data.frame(response_date = tmp |> html_elements("presidentskapet_oversikt > respons_dato_tid") |> html_text(),
                    version = tmp |> html_elements("presidentskapet_oversikt > versjon") |> html_text(),
                    last_name = tmp |> html_elements("medlem > etternavn") |> html_text(),
                    first_name = tmp |> html_elements("medlem > fornavn") |> html_text(),
                    from_date = tmp |> html_elements("medlem > fra_dato") |> html_text(),
                    party_id = tmp |> html_elements("medlem > parti_id") |> html_text(),
                    person_id = tmp |> html_elements("medlem > person_id") |> html_text(),
                    to_date = tmp |> html_elements("medlem > til_dato") |> html_text(),
                    position = tmp |> html_elements("medlem > verv") |> html_text())
  
  Sys.sleep(good_manners)
  
  return(tmp)
  
}