R/wiki_inthenews.R

In wikifacts: Get Facts and Data from Wikipedia and Wikidata

#' Generate news items from the Wikipedia main page on a specified date.
#'
#' @description
#' `wiki_inthenews()` generates news items from the Wikipedia main page on a specified date.
#'
#' @param n_facts An integer determining the number of facts that will be generated, up to a limit of the maximum facts for the date specified.
#' @param date A date string of the form YYYY-MM-DD.  Default value is a random date since 1 January 2015.
#' @param bare_fact Logical.  Determining whether the fact should be quoted as is or surrounded by a preamble and courtesy statement.
#'
#' @return A vector of strings with random 'in the news' items from Wikipedia's main page, if it exists for the date specified - otherwise "I got nothin'"
#'
#' @examples
#' wiki_inthenews(n_facts = 1, date = '2020-05-02')

wiki_inthenews <- function(n_facts = 1L, date = sample(seq(as.Date("2015-01-01"), Sys.Date() - 1, by = "day"), 1), bare_fact = FALSE) {

  locale <- Sys.getlocale("LC_TIME")

  if (.Platform$OS.type == "windows") {
    invisible(Sys.setlocale("LC_TIME", "English"))
  } else {
    invisible(Sys.setlocale("LC_TIME", "en_US.UTF-8"))
  }

  # get url from input and read html
  date <- as.Date(date)
  date1 <- format(date, "%Y_%B_")
  date2 <- gsub("^0+", "", format(date, "%d"))
  date_str <- paste0(date1, date2)

  invisible(Sys.setlocale("LC_TIME", locale))

  input <- paste0("https://en.wikipedia.org/wiki/Wikipedia:Main_Page_history/", date_str)

  tryCatch({
    input <- url(input, 'rb')
    wiki_page <- xml2::read_html(input, fill = TRUE)
    close(input)


    # scrape list data
    itn <- wiki_page %>%
      rvest::html_nodes(xpath = '//*[@id="mp-itn"]') %>%
      rvest::html_nodes("li") %>%
      rvest::html_text() %>%
      subset(nchar(.) > 40)

    n <- min(n_facts, length(itn))

    itn <- itn %>%
      sample(n)

    if (bare_fact == TRUE) {
      itn
    } else {
      paste0("Here's some news from ", format(date, "%d %B %Y"), ". ", itn, " (Courtesy of Wikipedia)")
    }
  },
  error = function (e) {"I got nothin'"},
  warning = function (w) {"I got nothin'"})

}