R/plosviews.R

In ropensci/rplos: Interface to the Search API for 'PLoS' Journals

#' Search PLoS Journals by article views.
#'
#' @export
#' @param search search terms (character)
#' @param byfield field to search by, e.g., subject, author, etc. (character)
#' @param views views all time (alltime) or views last 30 days (last30)
#'    (character)
#' @param limit number of results to return (integer)
#' @param ... Optional additional curl options passed to 
#' \code{\link[crul]{HttpClient}}
#' @examples \dontrun{
#' plosviews('10.1371/journal.pone.0002154', 'id', 'alltime')
#' plosviews('10.1371/journal.pone.0002154', 'id', 'last30')
#' plosviews('10.1371/journal.pone.0002154', 'id', 'alltime,last30')
#' plosviews(search='marine ecology', byfield='subject', limit=50)
#' plosviews(search='evolution', views = 'alltime', limit = 99)
#' plosviews('bird', views = 'alltime', limit = 99)
#' }

plosviews <- function(search, byfield = NULL, views = 'alltime', limit = NULL, ...) {
  args <- ploscompact(list(wt = "json", fq = "doc_type:full", rows = limit))
  if (is.null(byfield)) {
    byfield_ <- byfield
  } else {
    byfield_ <- paste(byfield, ":", sep = "")
  }
  if (!is.na(search)) {
    args$q <- paste(byfield_, '"', search, '"', sep = "")
  }
  if (!is.na(views)) {
    if (views == 'alltime') {
      args$fl <- 'id,counter_total_all'
    } else {
      if (views == 'last30') {
        args$fl <- 'id,counter_total_month'
      } else {
        args$fl <- 'id,counter_total_all,counter_total_month'
      }
    }
  }
  cli <- HttpClient$new(url = pbase())
  tt <- cli$get(query = args, ...)
  tt$raise_for_status()
	temp <- jsonlite::fromJSON(tt$parse("UTF-8"), FALSE)$response$docs
  df <- do.call(rbind, lapply(temp, function(x) data.frame(x, stringsAsFactors = FALSE)))
	df[order(df[,2]), ]
}