From f247f62c5e57bbbf3faef6196c0c1887ae5f116a Mon Sep 17 00:00:00 2001
From: Carson <cpsievert1@gmail.com>
Date: Tue, 5 May 2026 11:26:30 -0500
Subject: [PATCH 1/2] Add widgetDependencies() S3 generic, deprecate
 getDependency()

widgetDependencies() is a public S3 generic with character and htmlwidget
methods. The htmlwidget method returns all dependencies (YAML + binding +
runtime), fixing under-reporting when deps are added via createWidget().

Internally, toHTML() and shinyRenderWidget() now use widgetDependencies(x)
as the single canonical path for resolving widget dependencies.
---
 DESCRIPTION                       |  2 +-
 NAMESPACE                         |  3 ++
 R/htmlwidgets.R                   | 15 ++-------
 R/utils.R                         | 54 +++++++++++++++++++++++--------
 man/getDependency.Rd              |  9 +++---
 man/htmlwidgets-package.Rd        |  8 +++++
 man/widgetDependencies.Rd         | 28 ++++++++++++++++
 tests/testthat/test-htmlwidgets.R | 36 +++++++++++++++++++++
 8 files changed, 124 insertions(+), 31 deletions(-)
 create mode 100644 man/widgetDependencies.Rd

diff --git a/DESCRIPTION b/DESCRIPTION
index 4705ddb8..06bf7dde 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -34,4 +34,4 @@ Enhances:
 VignetteBuilder: 
     knitr
 Encoding: UTF-8
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.3
diff --git a/NAMESPACE b/NAMESPACE
index 160e645b..88ce0333 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -3,6 +3,8 @@
 S3method(as.tags,htmlwidget)
 S3method(print,htmlwidget)
 S3method(print,suppress_viewer)
+S3method(widgetDependencies,character)
+S3method(widgetDependencies,htmlwidget)
 export(JS)
 export(JSEvals)
 export(appendContent)
@@ -17,6 +19,7 @@ export(setWidgetIdSeed)
 export(shinyRenderWidget)
 export(shinyWidgetOutput)
 export(sizingPolicy)
+export(widgetDependencies)
 import(htmltools)
 importFrom(utils,browseURL)
 importFrom(utils,file.edit)
diff --git a/R/htmlwidgets.R b/R/htmlwidgets.R
index 460c5d74..204cbc89 100644
--- a/R/htmlwidgets.R
+++ b/R/htmlwidgets.R
@@ -207,12 +207,7 @@ toHTML <- function(x, standalone = FALSE, knitrOptions = NULL) {
     }
   )
 
-  deps <- c(
-    widget_dependencies(name, package),
-    x$dependencies
-  )
-
-  browsable(attachDependencies(html, deps, append = TRUE))
+  browsable(attachDependencies(html, widgetDependencies(x), append = TRUE))
 }
 
 lookup_func <- function(name, package) {
@@ -318,10 +313,6 @@ widgetF_html <- function(name, package, id, style, class, inline = FALSE, ...) {
 
 ## End unit test support functions #################################
 
-widget_dependencies <- function(name, package){
-  getDependency(name, package)
-}
-
 # Generates a <script type="application/json"> tag with the JSON-encoded data,
 # to be picked up by htmlwidgets.js for static rendering.
 widget_data <- function(x, id, ...){
@@ -499,7 +490,7 @@ shinyWidgetOutput <- function(outputId, name, width, height, package = name,
   tag <- tagList(tag)
 
   attachDependencies(
-    tag, widget_dependencies(name, package), append = TRUE
+    tag, widgetDependencies(name, package = package), append = TRUE
   )
 }
 
@@ -533,7 +524,7 @@ shinyRenderWidget <- function(expr, outputFunction, env, quoted, cacheHint = "au
         "Shiny render call")
     }
 
-    deps <- .subset2(instance, "dependencies")
+    deps <- widgetDependencies(instance)
     deps_payload <- lapply(
       htmltools::resolveDependencies(deps),
       shiny::createWebDependency
diff --git a/R/utils.R b/R/utils.R
index ef582ea2..ffd8f603 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -31,31 +31,35 @@ toJSON <- function(x) {
   structure(res, class = 'json')
 }
 
-#' Get js and css dependencies for  a htmlwidget
+#' Get HTML dependencies for a widget
 #'
-#' @param name name of the widget.
-#' @param package name of the package, defaults to the widget name.
+#' @param x A widget name (character) or an \code{htmlwidget} object.
+#' @param ... Currently unused.
+#' @param package Name of the package containing the widget (only used when
+#'   \code{x} is a character string). Defaults to the widget name.
+#' @return A list of \code{\link[htmltools]{htmlDependency}} objects.
 #' @export
-getDependency <- function(name, package = name){
-  config = sprintf("htmlwidgets/%s.yaml", name)
-  jsfile = sprintf("htmlwidgets/%s.js", name)
+widgetDependencies <- function(x, ...) {
+  UseMethod("widgetDependencies")
+}
+
+#' @rdname widgetDependencies
+#' @export
+widgetDependencies.character <- function(x, ..., package = x) {
+  name <- x
+  config <- sprintf("htmlwidgets/%s.yaml", name)
+  jsfile <- sprintf("htmlwidgets/%s.js", name)
 
-  # if yaml does not exist then assume no dependencies
-  #  in this cases dependencies should be provided through the
-  #  dependencies argument of createWidget
   widgetDep <- list()
   yaml_file <- system_file(config, package = package)
   if (file.exists(yaml_file)) {
-    config = yaml::yaml.load_file(yaml_file)
+    config <- yaml::yaml.load_file(yaml_file)
     widgetDep <- lapply(config$dependencies, function(l) {
-      l$package = package
+      l$package <- package
       do.call(htmlDependency, l)
     })
   }
 
-  # if js binding does not exist then assume provided through
-  #  some other mechanism such as a specified `htmlDependency` or `script` tag.
-  #  Note, this is a very special case.
   bindingDep <- if (file.exists(system_file(jsfile, package = package))) {
     htmlDependency(
       name = paste0(name, "-binding"),
@@ -80,6 +84,28 @@ getDependency <- function(name, package = name){
   )
 }
 
+#' @rdname widgetDependencies
+#' @export
+widgetDependencies.htmlwidget <- function(x, ...) {
+  name <- class(x)[1]
+  package <- attr(x, "package")
+  c(
+    widgetDependencies(name, package = package),
+    x$dependencies
+  )
+}
+
+
+#' Deprecated: use [widgetDependencies()] instead.
+#' @param name Widget name.
+#' @param package Package name.
+#' @keywords internal
+#' @export
+getDependency <- function(name, package = name) {
+  .Deprecated("widgetDependencies")
+  widgetDependencies(name, package = package)
+}
+
 
 prop <- function(x, path) {
   tryCatch({
diff --git a/man/getDependency.Rd b/man/getDependency.Rd
index b4af51e6..c55dd27c 100644
--- a/man/getDependency.Rd
+++ b/man/getDependency.Rd
@@ -2,15 +2,16 @@
 % Please edit documentation in R/utils.R
 \name{getDependency}
 \alias{getDependency}
-\title{Get js and css dependencies for  a htmlwidget}
+\title{Deprecated: use [widgetDependencies()] instead.}
 \usage{
 getDependency(name, package = name)
 }
 \arguments{
-\item{name}{name of the widget.}
+\item{name}{Widget name.}
 
-\item{package}{name of the package, defaults to the widget name.}
+\item{package}{Package name.}
 }
 \description{
-Get js and css dependencies for  a htmlwidget
+Deprecated: use [widgetDependencies()] instead.
 }
+\keyword{internal}
diff --git a/man/htmlwidgets-package.Rd b/man/htmlwidgets-package.Rd
index 11f891a8..2cd5a7fb 100644
--- a/man/htmlwidgets-package.Rd
+++ b/man/htmlwidgets-package.Rd
@@ -28,6 +28,14 @@ vignette("develop_advanced", package = "htmlwidgets")
 Source code for the package is available on GitHub:
 
 \url{https://github.com/ramnathv/htmlwidgets}
+}
+\seealso{
+Useful links:
+\itemize{
+  \item \url{https://github.com/ramnathv/htmlwidgets}
+  \item Report bugs at \url{https://github.com/ramnathv/htmlwidgets/issues}
+}
+
 }
 \author{
 Ramnath Vaidyanathan, Joe Cheng, JJ Allaire, and Yihui Xie
diff --git a/man/widgetDependencies.Rd b/man/widgetDependencies.Rd
new file mode 100644
index 00000000..6e8e2349
--- /dev/null
+++ b/man/widgetDependencies.Rd
@@ -0,0 +1,28 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/utils.R
+\name{widgetDependencies}
+\alias{widgetDependencies}
+\alias{widgetDependencies.character}
+\alias{widgetDependencies.htmlwidget}
+\title{Get HTML dependencies for a widget}
+\usage{
+widgetDependencies(x, ...)
+
+\method{widgetDependencies}{character}(x, ..., package = x)
+
+\method{widgetDependencies}{htmlwidget}(x, ...)
+}
+\arguments{
+\item{x}{A widget name (character) or an \code{htmlwidget} object.}
+
+\item{...}{Currently unused.}
+
+\item{package}{Name of the package containing the widget (only used when
+\code{x} is a character string). Defaults to the widget name.}
+}
+\value{
+A list of \code{\link[htmltools]{htmlDependency}} objects.
+}
+\description{
+Get HTML dependencies for a widget
+}
diff --git a/tests/testthat/test-htmlwidgets.R b/tests/testthat/test-htmlwidgets.R
index cac418b6..c06be727 100644
--- a/tests/testthat/test-htmlwidgets.R
+++ b/tests/testthat/test-htmlwidgets.R
@@ -42,3 +42,39 @@ test_that("Legacy methods work with tagList() and HTML()", {
     widget_html("widgetF", "htmlwidgets", id = "id", style = NULL, class = NULL)
   }, NA)
 })
+
+dep_names <- function(deps) {
+  deps <- Filter(Negate(is.null), deps)
+  vapply(deps, function(d) d$name, character(1))
+}
+
+test_that("widgetDependencies.character returns YAML + binding deps", {
+  deps <- widgetDependencies("nonexistent_widget", package = "htmlwidgets")
+  expect_true("htmlwidgets" %in% dep_names(deps))
+})
+
+test_that("widgetDependencies.htmlwidget returns YAML + binding + runtime deps", {
+  extra_dep <- htmltools::htmlDependency(
+    name = "extra-dep", version = "1.0", src = ".",
+    script = "extra.js"
+  )
+  w <- createWidget(
+    name = "nonexistent_widget",
+    x = list(),
+    package = "htmlwidgets",
+    dependencies = list(extra_dep)
+  )
+  deps <- widgetDependencies(w)
+  expect_true("htmlwidgets" %in% dep_names(deps))
+  expect_true("extra-dep" %in% dep_names(deps))
+})
+
+test_that("widgetDependencies.htmlwidget works with NULL dependencies", {
+  w <- createWidget(
+    name = "nonexistent_widget",
+    x = list(),
+    package = "htmlwidgets"
+  )
+  deps <- widgetDependencies(w)
+  expect_true("htmlwidgets" %in% dep_names(deps))
+})

From cd2bcc597d02b5a595816f2dff482fa108e38a34 Mon Sep 17 00:00:00 2001
From: Carson <cpsievert1@gmail.com>
Date: Tue, 5 May 2026 11:39:18 -0500
Subject: [PATCH 2/2] Add NEWS entry for widgetDependencies()

---
 NEWS.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index 8176f729..598dc165 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,7 @@
 # htmlwidgets (development version)
 
+* Added `widgetDependencies()`, an S3 generic for retrieving all HTML dependencies from a widget name (character) or object (htmlwidget). The htmlwidget method includes runtime dependencies passed via `createWidget(dependencies = ...)`, which were previously not accessible through the public API. `getDependency()` is now deprecated in favour of `widgetDependencies()`. (#255)
+
 * Moved `{rmarkdown}` from `Imports` to `Suggests`. It's now only required when calling `saveWidget(selfcontained = TRUE)`. (#455)
 
 * htmlwidgets hex sticker added