R/dcardmaincontent.R

In b05102139/DcardR: What the Package Does (One Line, Title Case)

#' @title DCard Board Content
#' @description Returns general post info in a specific board, where the post number and whether or not to sort by popular can be specified. The rate limit can also be altered, at the risk of being blocked by the API.
#' @param board
#' @param posts
#' @param by_popular
#' @param rate_limit
#'
#' @importFrom magrittr %>%
#' @importFrom tictoc tic toc
#' @importFrom vctrs vec_rbind
#' @return
#' @export
#'
#' @examples
dcardBoardContent <- function(board, posts, by_popular = F, rate_limit = 1){
  if(!(posts %% 1 == 0) | `>=`(0, posts)){
    stop("Posts must be a positive integer.")
  }
  pages <- ceiling(posts / 30)
  if(by_popular == F){
    base_url <- paste0('https://www.dcard.tw/_api/forums/',
                       board,
                       '/posts?popular=false')
  }
  if(by_popular == T){
    base_url <- paste0('https://www.dcard.tw/_api/forums/',
                       board,
                       '/posts?popular=true')
  }
  message(paste("Total pages:", pages))
  tictoc::tic("Page 1 complete")
  main_df <- jsonlite::fromJSON(base_url)
  last_art <- main_df$id[length(main_df$id)]
  pages <- (pages - 1)

  if(pages >= 1){
    Sys.sleep(rate_limit)
    tictoc::toc()
    for(i in 1:pages){
      tictoc::tic(paste("Page", (i + 1), "complete"))
      url <- paste0(base_url,"&before=", last_art)
      new_page <- jsonlite::fromJSON(url)
      last_art <- new_page$id[length(new_page$id)]
      main_df <- vctrs::vec_rbind(main_df, new_page)
      Sys.sleep(1)
      tictoc::toc()
    }
  }
  if(pages == 0){
    tictoc::toc()
  }
  message("Finished crawling pages.")
  main_df[1:posts,]
}