R/module_settings_server.R

In crp2a/gammaShiny: 'shiny' Applications for the R Package 'gamma'

#' Settings Server
#'
#' @param input provided by \pkg{Shiny}.
#' @param output provided by \pkg{Shiny}.
#' @param session provided by \pkg{Shiny}.
#' @param user_settings a [shiny::reactiveValues()] list.
#' @seealso [module_settings_ui()]
#' @family modules
#' @export
module_settings_server <- function(input, output, session, user_settings) {
  observe({
    colour <- try(khroma::colour(input$fig_colour), silent = TRUE)
    if (inherits(colour, "try-error")) {
      # Emulate ggplot2 default colours
      colour <- function(n) {
        hues <- seq(15, 375, length = n + 1)
        grDevices::hcl(h = hues, l = 65, c = 100)[1:n]
      }
    } else {
      colour <- colour
    }

    scale <- switch(
      input$fig_colour,
      `discrete rainbow` = khroma::scale_color_discreterainbow(),
      bright = khroma::scale_color_bright(),
      contrast = khroma::scale_color_highcontrast(),
      vibrant = khroma::scale_color_vibrant(),
      muted = khroma::scale_color_muted(),
      pale = khroma::scale_color_pale(),
      dark = khroma::scale_color_dark(),
      light = khroma::scale_color_light(),
      NULL
    )

    user_settings$digits <- input$digits
    user_settings$fig_width <- input$fig_width
    user_settings$fig_height <- input$fig_height
    user_settings$fig_units <- input$fig_units
    user_settings$fig_colour <- colour
    user_settings$fig_scale <- scale
  })

  # Render
  output$last_saved <- renderText({
    req(user_settings$saved)
    paste("Last saved at", user_settings$saved)
  })

  output$session <- renderPrint({
    utils::sessionInfo()
  })

  # Bookmark
  onBookmark(function(state) {
    user_settings$saved <- Sys.time()
    # state is a mutable reference object,
    # we can add arbitrary values to it.
    state$values$time <- user_settings$saved
  })

  onRestore(function(state) {
    user_settings$saved <- state$values$time
  })
}