Include useBusyIndicators() as a separate htmlDependency()

NEWS.md

@@ -2,7 +2,7 @@
 
 ## New features
 
-* Shiny's busy indicators (see `shiny::useBusyIndicators()` in shiny > v1.8.1.1) are now enabled automatically for all of bslib's `page_*()` functions or when bslib is used to provide Bootstrap 5 for a Shiny app. If this behavior isn't desirable (perhaps because a package like `{shinycssloaders}` is being used to indicate busy state), then disable by putting `shiny::useBusyIndicators(spinners=FALSE, pulse=FALSE)` in the page. (#1053)
+* Shiny's busy indicators (see `shiny::useBusyIndicators()` in shiny > v1.8.1.1) are now enabled automatically when bslib for the UI. If this behavior isn't desirable (perhaps because a package like `{shinycssloaders}` is being used to indicate busy state), then disable by putting `shiny::useBusyIndicators(spinners=FALSE, pulse=FALSE)` inside the UI definition. (#1053)
 
 ## Improvements
 

R/bs-dependencies.R

@@ -143,18 +143,32 @@ bs_theme_dependencies <- function(
         stylesheet = basename(out_file),
         script = basename(js_files),
         all_files = TRUE, # include font and map files
-        meta = list(viewport = "width=device-width, initial-scale=1, shrink-to-fit=no"),
-        # Enable busy indicators by default.
-        # This doesn't have much of anything to Bootstrap,
-        # but it's a convenient place to hang this feature's
-        # initialization code (so it works in Rmd etc).
-        head = if (isTRUE(version >= 5)) as.character(use_busy_indicators())
+        meta = list(viewport = "width=device-width, initial-scale=1, shrink-to-fit=no")
       )
     ),
+    busy_indicator_deps(),
     htmlDependencies(out_file)
   ))
 }
 
+# Busy indicators are orthogonal to Bootstrap, but since they have the potential
+# to introduce breaking changes, they aren't enabled by default in R/Shiny.
+# However, since bslib is the place for "modern UI" practices, we enable them by
+# default in bslib. Note also that the way in which busy indicators are enabled
+# is here is fairly consistent with how they're enabled in PyShiny...
+# https://github.com/posit-dev/py-shiny/blob/dc0b294/shiny/ui/_html_deps_py_shiny.py#L73-L81
+busy_indicator_deps <- function() {
+  if (is_installed("shiny", "1.8.1.9001")) {
+    list(htmlDependency(
+      name = "bslib-enable-busy-indicators",
+      version = get_package_version("bslib"),
+      src = "",
+      package = "bslib",
+      head = as.character(shiny::useBusyIndicators())
+    ))
+  }
+}
+
 
 #' Themeable HTML components
 #'

R/page.R

@@ -36,12 +36,6 @@ page <- function(..., title = NULL, theme = bs_theme(), lang = NULL) {
   )
 }
 
-use_busy_indicators <- function() {
-  # Use busy indicators were added in shiny 1.8.1.9001 (after 1.8.1.1)
-  ubi <- asNamespace("shiny")[["useBusyIndicators"]]
-  if (!is.null(ubi)) ubi()
-}
-
 #' @describeIn page A \pkg{bslib} wrapper for [shiny::fluidPage()], a fluid
 #'   Bootstrap-based page layout that extends to the full viewport width.
 #' @inheritParams shiny::fluidPage

tests/testthat/_snaps/page.md

@@ -53,8 +53,6 @@
           <script data-bslib-sidebar-init>bslib.Sidebar.initCollapsibleAll()</script>
         </div>
       </body>
-      <script>document.documentElement.dataset.shinyBusySpinners = 'true';
-      document.documentElement.dataset.shinyBusyPulse = 'true';</script>
 
 ---
 
@@ -78,6 +76,4 @@
           <script data-bslib-sidebar-init>bslib.Sidebar.initCollapsibleAll()</script>
         </div>
       </body>
-      <script>document.documentElement.dataset.shinyBusySpinners = 'true';
-      document.documentElement.dataset.shinyBusyPulse = 'true';</script>
 

tests/testthat/_snaps/page/card.html

@@ -7,6 +7,8 @@
 <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
 <link href="lib/bootstrap/bootstrap.min.css" rel="stylesheet" />
 <script src="lib/bootstrap/bootstrap.bundle.min.js"></script>
+<script>document.documentElement.dataset.shinyBusySpinners = 'true';
+document.documentElement.dataset.shinyBusyPulse = 'true';</script>
 <script src="lib/bs3compat/transition.js"></script>
 <script src="lib/bs3compat/tabs.js"></script>
 <script src="lib/bs3compat/bs3compat.js"></script>

tests/testthat/_snaps/page/modern-page.html

@@ -7,12 +7,12 @@
 <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
 <link href="lib/bootstrap/bootstrap.min.css" rel="stylesheet" />
 <script src="lib/bootstrap/bootstrap.bundle.min.js"></script>
+<script>document.documentElement.dataset.shinyBusySpinners = 'true';
+document.documentElement.dataset.shinyBusyPulse = 'true';</script>
 <script src="lib/bslib-component-js/components.min.js"></script>
 <script src="lib/bslib-component-js/web-components.min.js" type="module"></script>
 <link href="lib/bslib-component-css/bslib-component-css.min.css" rel="stylesheet" />
 
 </head>
 <body>A simple page without bs3compat dependencies</body>
-<script>document.documentElement.dataset.shinyBusySpinners = 'true';
-document.documentElement.dataset.shinyBusyPulse = 'true';</script>
 </html>