R/input_checks.R

In teal.transform: Functions for Extracting and Merging Data in the 'teal' Framework

# Contains modules to check the input provided to the `tm_*` functions is correct.
# In general, they are checking functions, in the sense that they call `stopifnot`
# if the conditions are not met.

#' Make sure that the extract specification is in list format
#'
#' `r lifecycle::badge("stable")`
#'
#' @param x (`data_extract_spec` or `list`) of `data_extract_spec` elements.
#' @param allow_null (`logical`) whether x can be `NULL`.
#'
#' @return `x` as a list if it is not already.
#'
#' @export
list_extract_spec <- function(x, allow_null = FALSE) {
  if (is.null(x)) {
    stopifnot(allow_null)
    return(NULL)
  }
  if (!checkmate::test_list(x, types = "data_extract_spec")) {
    x <- list(x)
  }
  stopifnot(checkmate::test_list(x, types = "data_extract_spec"))
  x
}

#' Checks that the `extract_input` specification does not allow multiple
#' selection
#'
#' `r lifecycle::badge("stable")`
#'
#' Stops if condition not met.
#'
#' @param extract_input (`list` or `NULL`) a list of `data_extract_spec`
#'
#' @return Raises an error when check fails, otherwise, it returns `NULL`, invisibly.
#'
#' @export
#'
check_no_multiple_selection <- function(extract_input) {
  # bug in is_class_list when NULL
  checkmate::assert_list(extract_input, types = "data_extract_spec", null.ok = TRUE)
  all(vapply(extract_input, function(elem) !isTRUE(elem$select$multiple), logical(1))) ||
    stop("extract_input variable should not allow multiple selection")
  invisible(NULL)
}