R/examples.R

In Novartis/tidymodules: A robust framework for developing shiny modules

#' @title Launcher for the tidymodules examples
#'
#' @description Helper function to launch the tidymodules examples.
#'
#' @param id Example ID. If null display list of examples with ID.
#' @param server boolean. Is this a server call?
#' @param options list of options to be passed to shinyApps or shinyDir
#'
#' @export
#'
#' @examples
#'
#' if (interactive()) {
#'   showExamples(1)
#' }
showExamples <- function(id = NULL, server = F, options = NULL) {
  examples <- list.dirs(system.file(package = "tidymodules", "shiny/examples"), recursive = F)
  if (is.null(id)) {
    names(examples) <- seq_len(length(examples))
    basename(examples)
  } else {
    if (!is.numeric(id)) {
      stop("Please provide a numeric value")
    }
    if (id > length(examples) || id < 1) {
      stop("Wrong ID provided")
    }

    if (server) {
      setwd(examples[id])
      if (!is.null(options)) {
        shiny::shinyAppDir(examples[id], options = options)
      } else {
        shiny::shinyAppDir(examples[id])
      }
    } else {
      shiny::runApp(examples[id])
    }
  }
}

#' @title check if list of package namespaces exist, load them or display relevant information
#'
#' @description Utility function for managing package dependencies for tidymodules examples
#'
#' @param packages character vector of package names
#'
#' @export
#'
#' @examples
#'
#' check_and_load("ggplot2")
#'
check_and_load <- function(packages) {
  missing <- NULL
  for (p in packages) {
    if (!requireNamespace(p, quietly = TRUE)) {
      missing <- c(missing, p)
    } else {
      library(p, character.only = TRUE)
    }
  }

  if (!is.null(missing)) {
    stop(
      "The package(s) above are needed for this shiny example to work, please install them first...\n",
      cli::cat_bullet(missing, bullet_col = "red"),
      call. = FALSE
    )
  }
}