R/bwr_auth.R

In brandwatchR: 'Brandwatch' API to R

#' Authenticate with the Brandwatch API
#'
#' Authenticates using specified username and password.
#' Also caches a local version of the authentication token unless otherwise specified.
#'
#' @param un
#' Your Brandwatch Username
#' @param pw
#' Your Brandwatch Password
#' @param refresh
#' (Boolean) Should the token be refreshed?
#' If no, a token will be read from a locally cached file '.bw_token' if this file is available.
#' If no token is available, or the refresh argument is TRUE, a new token will be requested and cached from the API.
#'
#' @param cache
#' (Boolean) Can the token be locally cached?
#' If TRUE, the token will be cached in the current working directory in '.bw_token'.
#' If FALSE, the token will be not be cached locally.
#'
#' @return
#' Invisibly returns the string containing the token returned by Brandwatch.
#' Your environment variable 'BW_TOKEN' will be set to the value of your authentication token.
#' @export
#'
#' @examples
#' \dontrun{bwr_auth(un = 'mickey@@mouse.com', pw = 'itsasmallworld')}
bwr_auth <- function(un = NULL, pw = NULL, refresh = FALSE, cache = TRUE) {

    if (refresh | !file.exists(".bw_token")) {
        if (is.null(un) | class(un) != "character" | length(un) != 1)
            stop("You must provide a username as a string of length one")
        if (is.null(pw) | class(pw) != "character" | length(pw) != 1)
            stop("You must provide a password as a string of length one")

        token_url <- paste0("https://api.brandwatch.com/oauth/token?", "username=", un, "&grant_type=api-password&client_id=brandwatch-api-client",
            "&password=", utils::URLencode(pw))
        r <- httr::POST(token_url)
        httr::stop_for_status(r)
        token <- httr::content(r)$access_token
        if (cache)
            saveRDS(token, ".bw_token")
    } else {
        token <- readRDS(".bw_token")
        message("Token read from cached file '.bw_token'")
    }
    Sys.setenv(BW_TOKEN = token)
    invisible(token)
}