R/slackr_setup.r

In hrbrmstr/slackr: Send Messages, Images, R Objects and Files to 'Slack' Channels/Users

#' Setup environment variables for Slack API access
#'
#' Initialize all the environment variables [slackr()] will need to use to
#' work properly.
#'
#' By default, [slackr()] (and other functions) will use the `#general`
#' room and a username of `slackr()` with no emoji.
#'
#' If a valid file is found at the location pointed to by `config_file`, the
#' values there will be used. The fields should be specified as such in the file:
#'
#' \preformatted{
#'  token: SLACK_TOKEN
#'  channel: #general
#'  username: slackr
#'  incoming_webhook_url: https://hooks.slack.com/services/XXXXX/XXXXX/XXXXX
#' }
#'
#' @param channel default channel to send the output to (chr) defaults to `#general`.
#' @param username the username output will appear from (chr) defaults to `slackr`.
#' @param icon_emoji which emoji picture to use (chr) defaults to none (can be
#'        left blank in config file as well).
#' @param incoming_webhook_url the Slack URL prefix to use (chr) defaults to none.
#' @param token Authentication token bearing required scopes.
#' @param config_file a configuration file (DCF) - see [read.dcf] - format
#'        with the config values.
#' @param echo display the configuration variables (bool) initially `FALSE`.
#' @param cache_dir the location for an on-disk cache. defaults to an in-memory cache if no location is specified.
#' @importFrom jsonlite toJSON
#' @return "Successfully connected to Slack"
#' @note You need a [Slack](https://slack.com) account and all your API URLs & tokens setup
#'       to use this package.
#' @seealso [slackr()], [slackr_dev()], [slackr_save()],
#'          [slackr_upload()]
#'
#' @examples
#' \dontrun{
#' # reads from default file (i.e. ~/.slackr)
#' slackr_setup()
#'
#' # reads from alternate config
#' slackr_setup(config_file = "/path/to/my/slackrconfig")
#'
#' # the hard way
#' slackr_setup(
#'   channel = "#code",
#'   incoming_webhook_url = "https://hooks.slack.com/services/XXXXX/XXXXX/XXXXX"
#' )
#' }
#'
#' @export
slackr_setup <- function(
  channel = "#general",
  username = "slackr",
  icon_emoji = "",
  incoming_webhook_url = "",
  token = "",
  config_file = Sys.getenv("SLACKR_CONFIG_FILE_PATH", unset = "~/.slackr"),
  echo = FALSE,
  cache_dir = ""
) {
  Sys.setenv(SLACK_CACHE_DIR = cache_dir)

  if (file.exists(config_file)) {
    config <- read.dcf(
      config_file,
      fields = c(
        "channel",
        "icon_emoji",
        "username",
        "incoming_webhook_url",
        "token"
      )
    )

    warn_for_args(
      config[, "token"],
      username = config[, "username"],
      icon_emoji = config[, "icon_emoji"]
    )

    Sys.setenv(SLACK_CHANNEL = config[, "channel"])
    Sys.setenv(SLACK_USERNAME = config[, "username"])
    Sys.setenv(SLACK_ICON_EMOJI = config[, "icon_emoji"])
    Sys.setenv(SLACK_INCOMING_WEBHOOK_URL = config[, "incoming_webhook_url"])
    Sys.setenv(SLACK_TOKEN = config[, "token"])
  } else {
    if (token == "" | is.null(token) | is.na(token) | missing(token)) {
      abort("No config file found. Please specify your Slack OAuth token\n   with the token argument in slackr_setup().")
    }

    warn_for_args(
      token,
      username = username,
      icon_emoji = icon_emoji
    )

    Sys.setenv(SLACK_CHANNEL = channel)
    Sys.setenv(SLACK_USERNAME = username)
    Sys.setenv(SLACK_ICON_EMOJI = icon_emoji)
    Sys.setenv(SLACK_INCOMING_WEBHOOK_URL = incoming_webhook_url)
    Sys.setenv(SLACK_TOKEN = token)
  }

  if (!grepl("?$", Sys.getenv("SLACK_INCOMING_WEBHOOK_URL"))) {
    Sys.setenv(SLACK_INCOMING_WEBHOOK_URL = sprintf("%s?", config[, "incoming_webhook_url"]))
  }

  if (length(Sys.getenv("SLACK_CHANNEL")) == 0) {
    Sys.setenv("SLACK_CHANNEL", "#general")
  }

  if (length(Sys.getenv("SLACK_USERNAME")) == 0) {
    Sys.setenv("SLACK_USERNAME", "slackr")
  }

  if (echo) {
    print(toJSON(
      as.list(
        Sys.getenv(c(
          "SLACK_CHANNEL",
          "SLACK_USERNAME",
          "SLACK_ICON_EMOJI",
          "SLACK_INCOMING_WEBHOOK_URL",
          "SLACK_TOKEN"
        ))
      ),
      pretty = TRUE,
      auto_unbox = TRUE
    ))
  }

  auth <- quiet_auth(
    Sys.getenv("SLACK_TOKEN")
  )

  if (auth) {
    return("Successfully connected to Slack")
  } else {
    abort("Could not connect to Slack with the token you provided. Are you sure you've set up your app correctly?")
  }
}

#' Create the config file used in `slackr_setup()`
#' @param filename the name of the config file to save. We recommend using a hidden file (starting with '.')
#' @param token Authentication token bearing required scopes.
#' @param incoming_webhook_url the incoming webhook URL (Default: whatever is set as an env var).
#' @param icon_emoji the icon emoji to use as the default.
#' @param username the username to send messages from (will default to "slackr" if no username is set).
#' @param channel Channel, private group, or IM channel to send message to. Can be an encoded ID, or a name. See the \href{https://api.slack.com/methods/chat.postMessage#channels}{chat.postMessage endpoint documentation} for details.
#' @importFrom rlang inform
#' @seealso [slackr_setup()]
#' @examples
#' \dontrun{
#' # using `create_config_file()` after `slackr_setup()`
#' create_config_file()
#'
#' # using `create_config_file()` before `slackr_setup()`
#' create_config_file(
#'   token = "xox-",
#'   incoming_webhook_url = "https://hooks-",
#'   channel = "#general",
#'   username = "slackr",
#'   icon_emoji = "tada"
#' )
#'
#' slackr_setup()
#' }
#' @return TRUE if successful (invisibly)
#' @export
create_config_file <- function(
  filename = "~/.slackr",
  token = Sys.getenv("SLACK_TOKEN"),
  incoming_webhook_url = Sys.getenv("SLACK_INCOMING_WEBHOOK_URL"),
  icon_emoji = Sys.getenv("SLACK_ICON_EMOJI"),
  username = Sys.getenv("SLACK_USERNAME"),
  channel = Sys.getenv("SLACK_CHANNEL")
) {
  username <- if (username == "") "slackr" else username
  channel <- if (channel == "") "#general" else channel

  write.dcf(
    list(
      token = token,
      incoming_webhook_url = incoming_webhook_url,
      icon_emoji = icon_emoji,
      username = username,
      channel = channel
    ),
    file = filename,
    append = FALSE
  )

  inform(
    paste("Successfully wrote config file to", filename)
  )

  return(
    invisible(TRUE)
  )
}

#' Unset env vars created by `slackr_setup()`
#' @seealso [slackr_setup()]
#' @examples
#' \dontrun{
#' slackr_teardown()
#' }
#' @return TRUE if successful (invisibly)
#' @export
slackr_teardown <- function() {
  env_vars <- c(
    "SLACK_TOKEN",
    "SLACK_CACHE_DIR",
    "SLACK_CHANNEL",
    "SLACK_ICON_EMOJI",
    "SLACK_INCOMING_WEBHOOK_URL",
    "SLACK_USERNAME"
  )

  invisible(
    lapply(
      env_vars,
      Sys.unsetenv
    )
  )

  inform("Successfully tore down environment variables created by slackr_setup()")

  return(
    invisible(TRUE)
  )
}