R/zzz.R

In GlobalParametrics/taRpan_readonly: The read-only taRpan R package for accessing tarpan data systems

readline_retry <- function(text, retries = 2, validator) {
  if (missing(validator) || is.null(validator))
    validator <- function(value) TRUE

  retried <- 0
  output <- readline(text)
  while (!validator(output) & (retries - retried) > 0) {
    retried <- retried + 1
    output <- readline(text)
  }

  if (!validator(output)) {
    message(sprintf("Giving up after %d retries, returning NULL.\n", retries))
    output <- NULL
  }

  output
}

tarpan_config_file <- function() {
  if (isTRUE(nchar(Sys.getenv("TARPAN_CONFIG")) > 0))
    Sys.getenv("TARPAN_CONFIG")
  else
    "~/.tarpan_readonly_config"
}

.onAttach <- function(libname, pkgname) {
  config_file_path <- tarpan_config_file()

  if (file.exists(config_file_path)) {
    tarpan_load_config()
    Sys.chmod(config_file_path, "0700")
  }

  if (interactive()) {
    if (!file.exists(config_file_path) ||
        !any(c("user", "password") %in% names(fromJSON(config_file_path)))) {

      cache_creds <- readline_retry(
        text = "Cache database username and password? (y\\n) ",
        retries = 1,
        validator = function(value) isTRUE(tolower(value) %in% c("y", "n"))
      )

      if (identical(cache_creds, "y")) {
        set_tarpan_credentials()
      } else {
        packageStartupMessage(
          "You can always set your Tarpan with set_tarpan_credentials"
        )
      }
    } else
      packageStartupMessage("Credentials found at ", config_file_path)
  }

  packageStartupMessage("Welcome to taRpan!")
}

env <- environment()

.onLoad <- function(libname, pkgname) {
  finalizer <- function(x) {
    x
    tarpan2_disconnect()
  }

  reg.finalizer(env, finalizer, onexit = TRUE)
}

.onUnload <- function(libpath) {
  tarpan2_disconnect()
}