Follow up to #1706: When runtime:shiny is used with bslib, call shiny…

…::bootstrapLib() inside html_document_base()'s preprocessor (instead of at run()-time)

The former time-point is too early -- it doesn't allow other output formats like flex_dashboard to modify the theme before passing it to html_document_base()

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: rmarkdown
 Type: Package
 Title: Dynamic Documents for R
-Version: 2.6.6
+Version: 2.6.7
 Authors@R: c(
   person("JJ", "Allaire", role = "aut", email = "[email protected]"),
   person("Yihui", "Xie", role = c("aut", "cre"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666")),

R/html_document_base.R

@@ -89,10 +89,17 @@ html_document_base <- function(theme = NULL,
     format_deps <- append(format_deps, html_dependency_header_attrs())
     if (!is.null(theme)) {
       format_deps <- append(format_deps, list(html_dependency_jquery()))
-      format_deps <- append(format_deps, bootstrap_dependencies(
-        # If TRUE, an as_bs_theme(theme) has been set globally (so users may customize it)
-        if (is_bs_theme(theme)) bslib::bs_global_get() else theme
-      ))
+      # theme was set globally pre-knit, and it may be modified during knit
+      if (is_bs_theme(theme)) {
+        theme <- bslib::bs_global_get()
+      }
+      bootstrap_deps <- if (is_bs_theme(theme) && is_shiny(runtime)) {
+        if (!is_available("shiny", "1.6.0")) stop("Using a {bslib} theme with `runtime: shiny` requires shiny 1.6.0 or higher.")
+        list(shiny::bootstrapLib(theme))
+      } else {
+        bootstrap_dependencies(theme)
+      }
+      format_deps <- append(format_deps, htmltools::resolveDependencies(bootstrap_deps))
     }
     else if (isTRUE(bootstrap_compatible) && is_shiny(runtime)) {
       # If we can add bootstrap for Shiny, do it

R/shiny.R

@@ -131,19 +131,13 @@ run <- function(file = "index.Rmd", dir = dirname(file), default_file = NULL,
 
   # determine the runtime of the target file
   target_file <- file %||% file.path(dir, default_file)
-  yaml_front <- if (length(target_file)) yaml_front_matter(target_file)
-  runtime <- yaml_front$runtime
-  theme <- render_args$output_options$theme
-  if (length(target_file)) {
-    format <- output_format_from_yaml_front_matter(read_utf8(target_file))
-    theme <- format$options$theme
-  }
+  runtime <- if (length(target_file)) yaml_front_matter(target_file)
 
   # run using the requested mode
   if (is_shiny_prerendered(runtime)) {
 
     # get the pre-rendered shiny app
-    app <- shiny_prerendered_app(target_file, render_args = render_args, theme = theme)
+    app <- shiny_prerendered_app(target_file, render_args = render_args)
   } else {
 
     # add rmd_resources handler on start
@@ -158,7 +152,7 @@ run <- function(file = "index.Rmd", dir = dirname(file), default_file = NULL,
     # combine the user-supplied list of Shiny arguments with our own and start
     # the Shiny server; handle requests for the root (/) and any R markdown files
     # within
-    app <- shiny::shinyApp(ui = rmarkdown_shiny_ui(dir, default_file, theme),
+    app <- shiny::shinyApp(ui = rmarkdown_shiny_ui(dir, default_file),
                            uiPattern = "^/$|^/index\\.html?$|^(/.*\\.[Rr][Mm][Dd])$",
                            onStart = onStart,
                            server = rmarkdown_shiny_server(
@@ -317,7 +311,7 @@ rmarkdown_shiny_server <- function(dir, file, auto_reload, render_args) {
 }
 
 # create the Shiny UI function
-rmarkdown_shiny_ui <- function(dir, file, theme) {
+rmarkdown_shiny_ui <- function(dir, file) {
   function(req) {
     # map requests to / to requests for the default--index.Rmd, or another if
     # specified
@@ -339,8 +333,7 @@ rmarkdown_shiny_ui <- function(dir, file, theme) {
     tags$div(
       tags$head(
         tags$script(src = "rmd_resources/rmd_loader.js"),
-        tags$link(href = "rmd_resources/rmd_loader.css", rel = "stylesheet"),
-        shiny_bootstrap_lib(theme)
+        tags$link(href = "rmd_resources/rmd_loader.css", rel = "stylesheet")
       ),
 
       # Shiny shows the outer conditionalPanel as long as the document hasn't

R/shiny_prerendered.R

@@ -4,10 +4,7 @@ shiny_prerendered_app <- function(input_rmd, render_args, theme) {
 
   # get rendered html and capture dependencies
   html <- shiny_prerendered_html(input_rmd, render_args)
-  deps <- c(
-    htmltools::htmlDependencies(html),
-    shiny_bootstrap_lib(theme)
-  )
+  deps <- htmltools::htmlDependencies(html)
 
   # create the server environment
   server_envir = new.env(parent = globalenv())
@@ -687,18 +684,3 @@ shiny_prerendered_data_file_name <- function(label, cache) {
   type <- ifelse(cache, ".cached", "")
   sprintf("%s%s.RData", label, type)
 }
-
-# Use me instead of html_dependency_bootstrap() in a shiny runtime to get
-# dynamic theming (i.e., have it work with session$setCurrentTheme())
-shiny_bootstrap_lib <- function(theme) {
-  theme <- resolve_theme(theme)
-  if (!is_bs_theme(theme)) {
-    return(NULL)
-  }
-  if (!is_available("shiny", "1.5.0.9007")) {
-    stop(
-      "Using a {bslib} theme with `runtime: shiny` requires shiny 1.5.0.9007 or higher."
-    )
-  }
-  shiny::bootstrapLib(theme)
-}