R/knlib_data_functions.R

In jyucsiro/knlibr: R Library for Knowledge Network (KN)

#' Search dataset in KN
#'
#' @param q Search query
#' @param offset Search offset
#' @param limit Number of results to return
#' @return Data frame result as <pid, title> from KN
#' @examples
#' kn_data_search('water', 'data', 0, 5)
kn_data_search <- function(q, offset, limit) {
  if (!requireNamespace("httr", quietly = TRUE)) {
    stop("httr needed for this function to work. Please install it.",
         call. = FALSE)
  }

  result <- knsearch_list(q, 'data', offset, limit)

  mylist <- list()
  for(i in 1:length(result)){
    curr <- result[[i]]
    pid <- curr$pid
    title <- curr$title
    row <- c(pid,title)
    print(row)
    mylist[[i]] <- row
  }
  df <- do.call("rbind",mylist) #combine all vectors into a matrix
  colnames(df) <- c("pid", "title")
  return(df)
}

#' Search dataset in KN
#'
#' @param q Search query
#' @param offset Search offset
#' @param limit Number of results to return
#' @return Data frame result as <pid, title> from KN
#' @export
#' @examples
#' kn_feat_search('water', 'data', 0, 5)
kn_feat_search <- function(q, offset, limit) {
  if (!requireNamespace("httr", quietly = TRUE)) {
    stop("httr needed for this function to work. Please install it.",
         call. = FALSE)
  }

  result <- knsearch_list(q, 'feature', offset, limit)

  mylist <- list()
  for(i in 1:length(result)){
    curr <- result[[i]]
    pid <- curr$pid
    name <- curr$name
    row <- c(pid,name)
    print(row)
    mylist[[i]] <- row
  }
  df <- do.call("rbind",mylist) #combine all vectors into a matrix
  colnames(df) <- c("pid", "name")
  return(df)
}


#' Search dataset in KN and return a list
#'
#' @param q Search query
#' @param type Type of thing to search for - either "data" or "feature"
#' @param offset Search offset
#' @param limit Number of results to return
#' @return Result list from KN with all fields in each item
#' @export
#' @examples
#' knsearch_list('water', 'data', 0, 5)
knsearch_list <- function(q, type, offset, limit) {
  if (!requireNamespace("httr", quietly = TRUE)) {
    stop("httr needed for this function to work. Please install it.",
         call. = FALSE)
  }

  get_url <- paste("http://kn.csiro.au/api/search/", type, sep="")
  resp <- GET(get_url,
              query = list(q = q, start = offset, limit = limit)
  )
  cont <- content(resp, as = "parsed", type = "application/json")

  return(cont)
}