R/arxiv_request.R

In skaltman/arxivapi: What the Package Does (One Line, Title Case)

#' Query the arXiv API.
#'
#' For instructions on writing queries, see the aRxiv package tutorial:
#' https://ropensci.org/tutorials/arxiv_tutorial/, specifically the "Search terms"
#' section.
#'
#'
#' @param query String with the API query
#' @param start Index to start at
#' @param limit Maximum number of papers to return
#' @param batch_size batch_size
#' @param sleep Seconds to sleep between batches
#' @param timeout Timeout seconds
#' @param sep Separator
#'
#' @return A tibble
#' @export
#'
#' @examples
#' \donttest{
#' arxiv_request(
#'   query = "cat:cs.AI",
#'   start = 0,
#'   limit = 5,
#'   batch_size = 1,
#'   sleep = 1
#' )
#' }
arxiv_request <-
  function(
    query,
    start = 0,
    limit,
    batch_size,
    sleep = 0,
    timeout = 30,
    sep = "|"
  ) {

    count <- aRxiv::arxiv_count(query)
    if (count < start + limit) {
      message(
        "The total number of papers is less than `limit`. Retrieving ",
        count - start,
        " papers instead."
      )
      limit <- count - start
    }

    url <- "http://export.arxiv.org/api/query"
    body <-
      list(
        search_query = query,
        start = start,
        max_results = as.integer(limit),
        sortOrder = "ascending"
      )

    if (limit > batch_size) {
      arxiv_batches(
        query = query,
        start = start,
        limit = limit,
        batch_size = batch_size,
        sleep = sleep,
        timeout = timeout,
        sep = sep
      )
    } else {
      send_request(url, body, timeout) %>%
        arxiv_as_tibble(sep = sep)
    }
  }



send_request <- function(url, body, timeout) {
  search_result <-
    try(
      httr::POST(
        url,
        body = body,
        httr::timeout(timeout)
      )
    )

  httr::stop_for_status(search_result)
}

arxiv_as_tibble <- function(search_result, sep = sep) {
  aRxiv:::result2list(search_result) %>%
    aRxiv:::get_entries() %>%
    aRxiv:::listresult2df(sep = sep) %>%
    as_tibble()
}