R/eol_search.R

In taxize: Taxonomic Information from Around the Web

#' Search for terms in EOL database.
#'
#' @export
#' @param sci (character) scientific name
#' @param page A maximum of 30 results are returned per page. This parameter
#' allows you to fetch more pages of results if there are more than
#' 30 matches (Default 1)
#' @param exact Will find taxon pages if the preferred name or any synonym
#' or common name exactly matches the search term.
#' @param filter_tid Given an EOL page ID, search results will be limited
#' to members of that taxonomic group
#' @param filter_heid Given a Hierarchy Entry ID, search results will be
#' limited to members of that taxonomic group
#' @param filter_by_string Given a search term, an exact search will be made
#' and that matching page will be used as the taxonomic group against which
#' to filter search results
#' @param cache_ttl The number of seconds you wish to have the response cached.
#' @param terms Deprecated, see `sci`
#' @param ... Curl options passed on to [crul::HttpClient]
#' @details It's possible to return JSON or XML with the EOL API. However,
#' 		this function only returns JSON for now.
#'
#' @return A data frame with four columns:
#'
#' * pageid: pageid, this is the same as the eolid you can get from
#' [get_eolid()]
#' * name: taxonomic name, may or may not contain the taxonomic authority
#' * link: URL for the taxon in question
#' * content: a string of semi-colon separated names. it's not clear
#' to us what these represent exactly, but figured why not give it to users
#' in case some may find it useful
#'
#' @examples \dontrun{
#' eol_search(sci='Homo')
#' eol_search(sci='Salix', verbose = TRUE)
#' eol_search(sci='Ursus americanus')
#' eol_search('Pinus contorta')
#' }

eol_search <- function(sci, page=1, exact=NULL, filter_tid=NULL,
  filter_heid=NULL, filter_by_string=NULL, cache_ttl=NULL, terms = NULL, ...) {

  pchk(terms, "sci")
	query <- gsub("\\s", "+", sci)
  args <- tc(list(q = query, page = page, exact = exact,
                  filter_by_taxon_concept_id = filter_tid,
                  filter_by_hierarchy_entry_id = filter_heid,
                  filter_by_string = filter_by_string,
                  cache_ttl = cache_ttl))
  cli <- crul::HttpClient$new(
    url = paste0(eol_url("search"), ".json"),
    headers = tx_ual,
    opts = list(...)
  )
  res <- cli$get(query = argsnull(args))
  res$raise_for_status()
  tt <- res$parse("UTF-8")
  stopifnot(res$response_headers$`content-type`[1] == 'application/json; charset=utf-8')
  out <- jsonlite::fromJSON(tt, FALSE, encoding = "utf-8")
  if (out$totalResults == 0 | length(out$results) == 0) {
    data.frame(pageid = NA, name = NA, stringsAsFactors = FALSE)
  } else {
    tmp <- dt2df(
      lapply(out$results, function(z) {
        z$content <- unique(unlist(z$content))
        data.frame(z, stringsAsFactors = FALSE)
      }), idcol = FALSE)
    stats::setNames(tmp, c("pageid", "name", "link", "content"))
  }
}