Modularize dependency handling in R

R/html-deps.R

@@ -27,3 +27,21 @@ createWebDependency <- function(dependency) {
 
   return(dependency)
 }
+
+
+# Given a Shiny tag object, process singletons and dependencies. Returns a list
+# with rendered HTML and dependency objects.
+processDeps <- function(tags, session) {
+  ui <- takeSingletons(tags, session$singletons, desingleton=FALSE)$ui
+  ui <- surroundSingletons(ui)
+  dependencies <- lapply(
+    resolveDependencies(findDependencies(ui)),
+    createWebDependency
+  )
+  names(dependencies) <- NULL
+
+  list(
+    html = doRenderTags(ui),
+    deps = dependencies
+  )
+}

R/notifications.R

@@ -69,9 +69,12 @@ showNotification <- function(ui, duration = 5, closeButton = TRUE,
   if (is.null(id))
     id <- randomID()
 
+  res <- processDeps(ui, session)
+
   session$sendNotification("show",
     list(
-      html = as.character(htmltools::as.tags(ui)),
+      html = res$html,
+      deps = res$deps,
       duration = if (!is.null(duration)) duration * 1000,
       closeButton = closeButton,
       id = id,

R/shinywrappers.R

@@ -276,19 +276,7 @@ renderUI <- function(expr, env=parent.frame(), quoted=FALSE, func=NULL) {
     if (is.null(result) || length(result) == 0)
       return(NULL)
 
-    result <- takeSingletons(result, shinysession$singletons, desingleton=FALSE)$ui
-    result <- surroundSingletons(result)
-    dependencies <- lapply(resolveDependencies(findDependencies(result)),
-      createWebDependency)
-    names(dependencies) <- NULL
-
-    # renderTags returns a list with head, singletons, and html
-    output <- list(
-      html = doRenderTags(result),
-      deps = dependencies
-    )
-
-    return(output)
+    processDeps(result, shinysession)
   })
 }