Cookbook

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Cookbook

# Build a valid IPC message envelope
msg <- RDesk::rdesk_message("get_data", list(filter = "cyl == 6"))
str(msg)
#> List of 5
#>  $ id       : chr "msg_177463054444.706_580"
#>  $ type     : chr "get_data"
#>  $ version  : chr "1.0"
#>  $ payload  :List of 1
#>   ..$ filter: chr "cyl == 6"
#>  $ timestamp: num 1.77e+09

Load a CSV with a file dialog

app$on_message("load_file", function(payload) {
  path <- app$dialog_open(
    title   = "Open CSV",
    filters = list("CSV files" = "*.csv")
  )
  if (is.null(path)) return(invisible(NULL))

  df <- utils::read.csv(path, stringsAsFactors = FALSE)
  app$send("file_loaded", list(
    rows     = nrow(df),
    cols     = names(df),
    filename = basename(path)
  ))
})

Render a ggplot2 chart

RDesk Explorer Boxplot RDesk Models Page

app$on_message("get_chart", async(function(payload) {
  p <- ggplot2::ggplot(mtcars,
         ggplot2::aes(wt, mpg, colour = factor(cyl))) +
       ggplot2::geom_point(size = 3) +
       ggplot2::theme_minimal()

  list(chart = rdesk_plot_to_base64(p))
}, app = app))

rdesk.on("get_chart_result", function(data) {
  document.getElementById("chart").src =
    "data:image/png;base64," + data.chart;
});

Show a toast notification

app$toast("File saved successfully", type = "success")
app$toast("Could not connect",       type = "error")
app$toast("Update available",        type = "info")

Save a file with a dialog

app$on_message("export_csv", function(payload) {
  path <- app$dialog_save(
    title        = "Save CSV",
    filters      = list("CSV files" = "*.csv"),
    default_name = "export.csv"
  )
  if (is.null(path)) return(invisible(NULL))

  write.csv(mtcars, path, row.names = FALSE)
  app$toast(paste("Saved to", basename(path)), type = "success")
})

Run a slow computation without freezing the UI

app$on_message("run_analysis", async(function(payload) {
  result <- slow_function(payload$data)
  list(
    summary = as.list(summary(result)),
    n       = length(result)
  )
}, app = app, loading_message = "Analysing..."))

Add a native menu

app$on_ready(function() {
  app$set_menu(list(
    File = list(
      "Open..."   = function() app$send("load_file", list()),
      "Export..." = function() app$send("export_csv", list()),
      "---",
      "Exit"      = app$quit
    ),
    View = list(
      "Refresh"   = function() app$send("refresh", list()),
      "Dark mode" = function() app$send("toggle_theme", list())
    ),
    Help = list(
      "About"     = function() {
        app$toast("MyApp v1.0.0 -- built with RDesk", type = "info")
      }
    )
  ))
})

Check for and install updates

# In app.R, before app$run()
rdesk_auto_update(
  current_version = "1.0.0",
  version_url     = "https://yourserver.com/latest.txt",
  download_url    = "https://yourserver.com/MyApp-setup.exe",
  app             = app
)

Host a plain text file at version_url containing only the latest version string, e.g. 1.1.0. RDesk checks it silently on launch and installs the update if a newer version is available.

Send data when the app starts

app$on_ready(function() {
  df <- load_initial_data()
  app$send("data_ready", list(
    rows = lapply(seq_len(nrow(df)), function(i) as.list(df[i,])),
    cols = names(df),
    n    = nrow(df)
  ))
})

Handle errors gracefully

app$on_message("risky_operation", async(function(payload) {
  tryCatch({
    result <- operation_that_might_fail(payload)
    list(success = TRUE, data = result)
  }, error = function(e) {
    list(success = FALSE, error = e$message)
  })
}, app = app))

rdesk.on("risky_operation_result", function(data) {
  if (!data.success) {
    showError(data.error);
    return;
  }
  renderResult(data.data);
});

Detect if running as a built app vs dev mode

if (rdesk_is_bundle()) {
  # Running as distributed exe
  data_path <- file.path(getwd(), "data", "config.json")
} else {
  # Running in development via source("app.R")
  data_path <- file.path(app_dir, "data", "config.json")
}

These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.
Health stats visible at Monitor.