helpers.R

.check_req_packages <- function(x, note = "") {
  res <- unlist(suppressWarnings(lapply(x, requireNamespace, quietly = TRUE)))
  if (!all(res)) {
    if (!interactive()) {
      stop(note, "Some required packages are not installed. Make sure you have
               these packages: ", paste0(x[!res], collapse = ", "),
           call. = FALSE
      )
    }
    op <- options("warn")
    on.exit(options(op))
    options(warn = 1)
    warning(note, "The following packages are required for this function but
                   cannot be loaded: ", paste0(x[!res], collapse = ", "),
            call. = FALSE)
    choice <- readline(prompt = "Should I try to install these packages? (Y/N)")
    if (choice %in% c("Y", "y")) {
      utils::install.packages(x[!res])
      res <- unlist(suppressWarnings(lapply(x, requireNamespace, quietly = TRUE)))
      if (!all(res)) {
        stop("Not all packages could be installed successfully. The following could still not be loaded: ", paste0(x[!res], collapse = ", "),
             call. = FALSE
        )
      }
      return(TRUE)
    }
    stop("Cannot proceed without these packages.", call. = FALSE)
  }
}