Merge pull request #294 from Appsilon/support-bookmarking

Support bookmarking

Author: kamilzyla

R/app.R

@@ -42,13 +42,18 @@ load_main_module <- function() {
 }
 
 as_top_level <- function(shiny_module) {
+  # Necessary to avoid infinite recursion / bugs due to lazy evaluation:
+  # https://adv-r.hadley.nz/function-factories.html?q=force#forcing-evaluation
+  force(shiny_module)
+
   list(
-    ui = shiny_module$ui("app"),
+    # Wrap the UI in a function to support Shiny bookmarking.
+    ui = function(request) shiny_module$ui("app"),
     server = function(input, output) shiny_module$server("app")
   )
 }
 
-with_head_tags <- function(ui) {
+attach_head_tags <- function(ui) {
   shiny::tagList(
     shiny::tags$head(
       shiny::tags$script(src = "static/js/app.min.js"),
@@ -59,6 +64,12 @@ with_head_tags <- function(ui) {
   )
 }
 
+with_head_tags <- function(ui) {
+  # The top-level UI must be a function for Shiny bookmarking to work.
+  if (is.function(ui)) function(request) attach_head_tags(ui(request))
+  else attach_head_tags(ui)
+}
+
 #' Rhino application
 #'
 #' The entrypoint for a Rhino application.

pkgdown/_pkgdown.yml

@@ -47,6 +47,8 @@ navbar:
           href: articles/how-to/manage-r-dependencies.html
         - text: Manage secrets and environments
           href: articles/how-to/manage-secrets-and-environments.html
+        - text: Enable Shiny bookmarking
+          href: articles/how-to/enable-shiny-bookmarking.html
         - text: Keep multiple apps in a single repository
           href: articles/how-to/keep-multiple-apps-in-a-single-repository.html
         - text: Use Rhino on Windows

vignettes/how-to/enable-shiny-bookmarking.Rmd

@@ -0,0 +1,40 @@
+---
+title: "How-to: Enable Shiny bookmarking"
+output: rmarkdown::html_vignette
+vignette: >
+  %\VignetteIndexEntry{How-to: Enable Shiny bookmarking}
+  %\VignetteEngine{knitr::rmarkdown}
+  %\VignetteEncoding{UTF-8}
+---
+
+To use Shiny [bookmarking](https://shiny.rstudio.com/articles/bookmarking-state.html),
+call `shiny::enableBookmarking()` somewhere in your `main.R`:
+
+```r
+box::use(
+  shiny,
+)
+
+shiny$enableBookmarking()
+
+#' @export
+ui <- function(id) {
+  ns <- shiny$NS(id)
+  shiny$bootstrapPage(
+    shiny$bookmarkButton(),
+    shiny$textInput(ns("name"), "Name"),
+    shiny$textOutput(ns("message"))
+  )
+}
+
+#' @export
+server <- function(id) {
+  shiny$moduleServer(id, function(input, output, session) {
+    output$message <- shiny$renderText(paste0("Hello ", input$name, "!"))
+  })
+}
+```
+
+If you are using a [legacy entrypoint](https://appsilon.github.io/rhino/reference/app.html#legacy-entrypoint),
+be sure to make your UI a function
+as described in the details section of `shiny::enableBookmarking()`.