R/utils.R

In rywhale/kiwisR: A Wrapper for Querying KISTERS 'WISKI' Databases via the 'KiWIS' API

#' Hub selection handling
#' @noRd
#' @description Checks input against defaults
#' @keywords internal
check_hub <- function(hub) {
  # Identify default hubs
  default_hubs <- list(
    "kisters" = "http://kiwis.kisters.de/KiWIS/KiWIS?",
    "swmc" = "https://www.swmc.mnr.gov.on.ca/KiWIS/KiWIS?",
    "quinte" = "http://waterdata.quinteconservation.ca/KiWIS/KiWIS?"
  )

  # Hub selection
  if (!is.character(hub) | nchar(hub) == 0) {
    stop(
      "`hub` argument must be a character- either a URL or one of the following defaults: ",
      paste(c("", names(default_hubs)), collapse = "\n"),
      "See https://github.com/rywhale/kiwisR for more information."
    )
  }

  if (!hub %in% names(default_hubs)) {
    # Non-default KiWIS URL
    api_url <- hub
  } else {
    api_url <- default_hubs[[which(names(default_hubs) == hub)]]
  }

  api_url
}

#' User provided date string checking
#' @noRd
#' @description Checks user provided date strings to ensure they can be cast to yyyy-mm-dd
#' @keywords internal
check_date <- function(start_date, end_date) {
  start_status <- tryCatch(
    {
      lubridate::ymd(start_date)
    },
    warning = function(w) {
      stop("start_date must be in yyyy-mm-dd format", call. = FALSE)
    }
  )

  end_status <- tryCatch(
    {
      lubridate::ymd(end_date)
    },
    warning = function(w) {
      stop("end_date must be in yyyy-mm-dd format", call. = FALSE)
    }
  )

  if (lubridate::ymd(start_date) > lubridate::ymd(end_date)) {
    stop("start_date is greater than end_date")
  }
}

#' Checking if internet connection available
#' @noRd
#' @description Checks if connection to internet can be made. Useful to check before running API-related tests
#' @author Sam Albers
#' @keywords internal
has_internet <- function() {
  z <- try(suppressWarnings(
    readLines("https://www.google.ca", n = 1)
  ), silent = TRUE)
  !inherits(z, "try-error")
}