R/user_info.R

In nfox29/photosearcher: Photo Searcher

#' Get user information
#'
#' Takes Flickr user ID and returns the profile data.
#'
#' Uses the flickr.profile.getProfile API method from the Flickr API. See
#' \url{https://www.flickr.com/services/api/flickr.profile.getProfile.html} for
#' more information on the API method.
#'
#' See \url{https://www.pixsy.com/academy/flickr-id/} for a guide on finding
#' your Flickr ID.
#'
#'When running the function you need an API key saved as
#'photosearcher_key.sysdata in your working directory. If this is the first
#'function you run you will be prompted to create and enter your API key. The
#'API key will then be saved as photosearcher_key.sysdata in your working
#'directory and is used for all function.
#'
#' @param user_id character. The id of the user you wish to obtain information
#'   for.
#'
#' @return data.frame. Dataframe of 5 variables from the searched users publicly
#'   available information: id, occupation, hometown, city, country.
#'
#' @family User information
#'
#' @export
#'
#' @examples
#' \dontrun{
#' user_info(user_id = "155421853@N05")
#' }
user_info <- function(user_id) {

  # this checks for the presence of a key, if no key it prompts the user to
  # create one, it then checks the validity of the key
  api_key <- create_and_check_key()

  id_info <- dplyr::bind_rows(lapply(
    user_id, function(x) user_info_single(x, api_key)))

  id_info <- data.frame(id = id_info$id,
                    occupation = id_info$occupation,
                    hometown = id_info$hometown,
                    city = id_info$city,
                    country = id_info$country,
                    stringsAsFactors = FALSE)

  id_info <- data.frame(lapply(id_info, as.character), stringsAsFactors=FALSE)

   return(id_info)
}

#' @noRd
# get a single user's info (for use in a vectorised function)
user_info_single <- function(user_id, api_key) {
  get_info <- paste("https://api.flickr.com/services/rest/",
                    "?method=flickr.profile.getProfile&api_key=",
                    api_key,
                    "&user_id=",
                    user_id,
                    sep = "")

  user_xml <- search_url(base_url = get_info)

  if (!is.null(user_xml)) {

    #check that ID is valid
    warn <- data.frame(xml2::xml_attrs(xml2::xml_children(user_xml)))

    if (warn[2,] == "Invalid NSID provided"){

      warning(paste("User ID ", user_id, " is not valid", sep = ""))

      out <- NULL

    } else {

      user_atts <- xml2::xml_find_all(user_xml,
                                      "//profile",
                                      ns = xml2::xml_ns(user_xml))
      out <- dplyr::bind_rows(lapply(
        xml2::xml_attrs(user_atts), function(x) data.frame(
          as.list(x), stringsAsFactors = FALSE)))

}

  }

  return(out)
}