R/result_parse.R

Defines functions abbrev get_highlight get_var result_asdf

Documented in get_highlight result_asdf

# BSD_2_clause

#' Extract a data.frame from Elastic query results
#'
#' Elastic query results are returned as a complex nested list that is
#' reasonably well-structured but a pain to parse. The basic \code{Search}
#' function of \link[elastic]{elastic} has a flag, \code{asdf}, to return the
#' results as a data.frame, but there is no generic function to extract the
#' data.frame. This function is tailored to the esadocs index, used in testing,
#' which includes a field (Scientific_Name) that is an array in elasticsearch
#' (list in R) and doesn't coerce to a single variable just using
#' \code{as.data.frame(res)}.
#'
#' @param res An elasticsearch query result
#' @return A data.frame of document results
#' @importFrom dplyr bind_rows
#' @export
result_asdf <- function(res) {
  return(NULL)
  # score_ls <- vector("list", length(res))
  # res_ls <- vector("list", length(res))
  # print(names(res[[1]]))
  # for(i in 1:length(res)) {     # NOTE: lapply doesn't work for some reason
  #   score_ls[[i]] <- res[[i]]$`_score`
  #   type <- get_var(res[[i]]$`_source`, "type")
  #   title <- get_var(res[[i]]$`_source`, "title")
  #   date <- get_var(res[[i]]$`_source`, "date")
  #   file_name <- get_var(res[[i]]$`_source`, "file_name")
  #   link <- get_var(res[[i]]$`_source`, "link")
  #   pdf_path <- get_var(res[[i]]$`_source`, "pdf_path")
  #   txt_path <- get_var(res[[i]]$`_source`, "txt_path")
  #   # raw_text <- get_var(res[[i]]$`_source`, "raw_txt")
  #   pdf_md5 <- get_var(res[[i]]$`_source`, "pdf_md5")
  #   n_pages <- get_var(res[[i]]$`_source`, "n_pages")
  #   geo <- get_var(res[[i]]$`_source`, "geo")
  #   tags <- get_var(res[[i]]$`_source`, "tags")
  #   fr_citation_page <-  get_var(res[[i]]$`_source`, "fr_citation_page")
  #   plan_act_status <-  get_var(res[[i]]$`_source`, "plan_act_status")
  #   plan_status <-  get_var(res[[i]]$`_source`, "plan_status")
  #   federal_agency <- get_var(res[[i]]$`_source`, "federal_agency")
  #   activity_code <-  get_var(res[[i]]$`_source`, "activity_code")
  #   ch_status <- get_var(res[[i]]$`_source`, "ch_status")
  #   doc_type <- get_var(res[[i]]$`_source`, "doc_type")
  #   services <- get_var(res[[i]]$`_source`, "services")
  #   spp_tmp <- paste(res[[i]]$`_source`$species, collapse = "<br>")
  #   cur_dat <- data.frame(type = type,
  #                         title = title,
  #                         date = date,
  #                         file_name = file_name,
  #                         link = link,
  #                         pdf_path = pdf_path,
  #                         txt_path = txt_path,
  #                         # raw_txt = raw_text,
  #                         pdf_md5 = pdf_md5,
  #                         n_pages = n_pages,
  #                         fr_citation_page = fr_citation_page,
  #                         federal_agency = federal_agency,
  #                         activity_code = activity_code,
  #                         ch_status = ch_status,
  #                         doc_type = doc_type,
  #                         species = spp_tmp,
  #                         geo = geo,
  #                         tags = tags,
  #                         stringsAsFactors = FALSE)
  #   # names(cur_dat)[7] <- "raw_txt"
  #   res_ls[[i]] <- cur_dat
  # }
  # res_df <- suppressWarnings(dplyr::bind_rows(res_ls))
  # res_df$score <- unlist(score_ls)
  # return(res_df)
}

get_var <- function(src, varname) {
  ifelse(is.null(src[[varname]]), NA, src[[varname]])
}

#' Return highlighted text from elasticsearch results
#'
#' Highlighting the matched text can be used in displaying the search
#' results, much as The Google does.
#'
#' @param res An Elastic result object
#' @return A vector of highlighted matches
#' @export
get_highlight <- function(res) {
  res_ls = vector("list", length(res))

  # unfortunately, lapply doesn't seem to work well over an ES result object,
  # at least not without getting way more complicated than using a for loop
  for(i in 1:length(res)) {
    hi_tmp <- lapply(res[[i]]$highlight, FUN = abbrev)
    hi_tmp <- str_replace_all(hi_tmp,
                              "[ ]{2,}|\n",
                              " ")
    res_ls[[i]] <- hi_tmp
  }
  res_vec <- unlist(res_ls)
  return(res_vec)
}

abbrev <- function(x) {
  if(length(x) > 3) {
    paste(x[1:3], collapse = " ... ")
  } else {
    paste(x, collapse = " ... ")
  }
}
jacob-ogre/esadocs documentation built on May 18, 2019, 8 a.m.