Clean timezone module (#111)

* Clean timezone UI.

Closes #99.
Closes #105.

* Deploy with app.prod = TRUE.

* Use tzdb to try to standardize results across machines.

.Rbuildignore

@@ -11,3 +11,5 @@
 ^data-raw$
 ^app\.R$
 ^rsconnect$
+_\.new\.png$
+_disable_autoload\.R$

.gitignore

@@ -6,3 +6,5 @@ bookclubs4ds-service-account.json
 rsconnect
 .secret
 .Renviron
+# {shinytest2}: Ignore new debug snapshots for `$expect_values()`
+*_.new.png

DESCRIPTION

@@ -20,6 +20,7 @@ Imports:
     golem (>= 0.3.1),
     googledrive,
     googlesheets4,
+    htmltools,
     jsonlite,
     lubridate,
     rhandsontable,
@@ -28,15 +29,16 @@ Imports:
     shinyslack (>= 0.0.0.9008),
     stringr,
     tibble,
-    tidyr
+    tidyr,
+    tzdb
 Suggests: 
     pkgload,
     roxygen2,
+    shinytest2,
     testthat (>= 3.0.0)
 Remotes:
     r4ds/bookclubdata,
     r4ds/shinyslack
+Config/testthat/edition: 3
 Encoding: UTF-8
-LazyData: true
 RoxygenNote: 7.2.3
-Config/testthat/edition: 3

R/app_server.R

@@ -1,10 +1,10 @@
 #' The application server-side
 #'
-#' @param input,output,session Internal parameters for {shiny}.
-#'     DO NOT REMOVE.
+#' @param input,output,session Internal parameters for shiny.
 #' @keywords internal
 .app_server <- function(input, output, session) {
   slack_user_info <- .user_server()
+  timezone <- .timezone_server()
 
   approved_books <- bookclubdata::approved_books(refresh = TRUE)
   signups <- reactive({
@@ -20,14 +20,14 @@
   # works and other attempts didn't.
   observe({
     req(
-      input[[NS("timezone", "selected_zone")]],
+      timezone(),
       approved_books,
       signups(),
       slack_user_info()[["user_id"]]
     )
     output[[NS("calendar", "availability")]] <- .calendar_selector(
       slack_user_info()[["user_id"]],
-      input[[NS("timezone", "selected_zone")]],
+      timezone(),
       signups()
     )
   })
@@ -38,7 +38,7 @@
       slack_user_info()[["display_name"]],
       slack_user_info()[["user_id"]],
       input$book_name,
-      input[[NS("timezone", "selected_zone")]],
+      timezone(),
       input[[NS("calendar", "availability")]]
     ),
     priority = 1000

R/timezone.R

@@ -1,4 +1,4 @@
-#' UI to Select a Timezone
+#' UI to select a timezone
 #'
 #' @inheritParams .shared-parameters
 #'
@@ -8,42 +8,62 @@
 .timezone_ui <- function(id = "timezone") {
   return(
     tagList(
-      # Add HTML to the page to store the timezone.
+      # Add an invisible input to the page to store the JS-detected timezone.
       tags$input(
         type = "text",
         id = NS(id, "client_zone"),
         name = "Client zone",
         style = "display: none;"
       ),
+      # Add Javascript to detect the user timezone and fill the input.
+      .timezone_ui_javascript(),
+      # The user can override the detected timezone (or fill one in if JS
+      # fails). The available choices can be overridden in the server.
       selectInput(
         inputId = NS(id, "selected_zone"),
-        label = "Select Your Time Zone",
+        label = "Select your timezone",
         choices = c(
-          "DETECTING TIMEZONE" = "",
-          OlsonNames()
+          "...detecting timezone..." = "",
+          tzdb::tzdb_names()
         )
       )
     )
   )
 }
 
+.timezone_ui_javascript <- function() {
+  htmltools::htmlDependency(
+    name = "timezone_detect",
+    version = "1.0.0",
+    src = "js",
+    package = "bookclubber",
+    script = "timezone_detect.js"
+  )
+}
+
 #' A module for setting timezones.
 #'
 #' @inheritParams .shared-parameters
+#' @param allowed_zones A character vector of allowed timezones.
 #'
-#' @return A [shiny::moduleServer()] to update the timezone input using
-#'   javascript.
+#' @return The selected timezone as a reactive.
 #' @keywords internal.
-.timezone_server <- function(id = "timezone") {
+.timezone_server <- function(id = "timezone",
+                             allowed_zones = tzdb::tzdb_names()) {
   moduleServer(id, function(input, output, session) {
     # Inspired by https://github.com/rpodcast/shinycal.
     observe({
       tz <- input$client_zone
-      if (is.null(tz) || !tz %in% OlsonNames()) tz <- NULL
+      if (is.null(tz) || !tz %in% allowed_zones) tz <- NULL
       updateSelectInput(
         inputId = "selected_zone",
+        choices = c(
+          "PLEASE SELECT A TIMEZONE" = "",
+          allowed_zones
+        ),
         selected = tz
       )
     })
+    reactive(input$selected_zone)
   })
 }