R/startShinyItemAnalysis.R

In ShinyItemAnalysis: Test and Item Analysis via Shiny

#' Start ShinyItemAnalysis application
#'
#' An interactive shiny application to run test and item analysis. By default,
#' the function runs the application as a background process ("Jobs" tab in the
#' "RStudio" IDE). User is then free to use the `R` Console for other work
#' and to try the sample R code examples. You can still run the app the usual
#' way in the console by specifying `background = FALSE`.
#'
#' @param background *logical*, should the application be run as a
#'   background process (in the 'RStudio')?
#'
#' @inheritDotParams utils::install.packages -pkgs -libs_only
#'
#' @return No return value. Called for side effects.
#'
#' @author
#' Patricia Martinkova \cr
#' Institute of Computer Science of the Czech Academy of Sciences \cr
#' \email{martinkova@@cs.cas.cz}
#'
#' Adela Hladka \cr
#' Institute of Computer Science of the Czech Academy of Sciences \cr
#' \email{hladka@@cs.cas.cz}
#'
#' Jan Netik \cr
#' Institute of Computer Science of the Czech Academy of Sciences \cr
#' \email{netik@@cs.cas.cz}
#'
#' @examples
#' \dontrun{
#' startShinyItemAnalysis()
#' startShinyItemAnalysis(background = FALSE)
#' }
#'
#' @aliases run_app
#'
#' @importFrom rstudioapi isAvailable jobRunScript jobSetStatus executeCommand
#'
#' @export
startShinyItemAnalysis <- function(background = TRUE, ...) {
    check_app_deps(...) # dots are for install.packages() options

  run_app_script <- '
  appDir <- system.file("ShinyItemAnalysis", package = "ShinyItemAnalysis")
  if (appDir == "") {
    stop("Could not find the app. Try re-installing `ShinyItemAnalysis`.", call. = FALSE)
  }
  shiny::runApp(appDir, display.mode = "normal", launch.browser = TRUE)
  '

  if (!isAvailable()) {
    message(
      "\n---------------------------------------------------------------\n",
      "ShinyItemAnalysis will run in the console as usual.\n",
      "To run the app in a background process, please use RStudio IDE.\n",
      "---------------------------------------------------------------"
    )
    Sys.sleep(5)
    eval(parse(text = run_app_script))
  } else if (background) {
    temp_script <- tempfile(fileext = ".R")
    writeLines(run_app_script, con = temp_script)

    job_id <- tryCatch(
      {
        jobRunScript(temp_script, name = "ShinyItemAnalysis")
      },
      error = function(e) {
        message(
          "There was an error running the app as a background job.\n",
          "The issue may be that your username contains special characters.\n",
          "Please use `startShinyItemAnalysis(background = FALSE)`."
        )
        return("fail")
      }
    )

    if (job_id != "fail") {
      jobSetStatus(
        job_id,
        "The app is running in background. You can close it with the STOP button."
      )

      executeCommand("activateConsole")

      message(
        "\n----------------------------------------------------------------\n",
        "ShinyItemAnalysis has started as a background process.\n",
        "The process automatically stops as you close the browser window.\n",
        "----------------------------------------------------------------"
      )
    }
  } else {
    eval(parse(text = run_app_script))
  }
}


#' @rdname startShinyItemAnalysis
#' @export
run_app <- function(background = TRUE, ...) {
  startShinyItemAnalysis(background = background, ...)
}


#' Check that all dependencies are satisfied
#'
#' @keywords internal
#' @noRd
#'
#' @importFrom rlang check_installed
#'
check_app_deps <- function(...) {
  # get Suggests info from the DESCRIPTION
  suggests <- read.dcf(
    system.file("DESCRIPTION", package = "ShinyItemAnalysis"),
    fields = "Suggests"
  )

  # split the string to individual packages, trim whitespaces
  suggests <- unlist(strsplit(suggests, ",[[:space:]]*"))

  # remove any newline chars that might confuse regex of rlang::check_installed
  suggests <- gsub("\n", " ", suggests)

  # ignore testthat as it is not required to run the app
  suggests <- suggests[!grepl("^testthat", suggests)]

  # check with the provided reason
  check_installed(suggests, reason = "to run the app.")
}