refine Shiny Gadget

R/gadget.R

@@ -1,14 +1,23 @@
 .pal <- function() {
-  pal_fn <- .pal_app()
-  if (is.null(pal_fn) || identical(pal_fn, ".pal_rs__")) {
-    return(NULL)
+  # suppress "Listening on..." message and rethrow errors with new context
+  try_fetch(
+    suppressMessages(pal_fn <- .pal_app()),
+    error = function(cnd) {cli::cli_abort(conditionMessage(cnd), call = NULL)}
+  )
+
+  if (is.null(pal_fn) || identical(pal_fn, ".pal_rs_")) {
+    return(invisible())
   }
+
+  # call the binding associated with the chosen pal
   try_fetch(
     do.call(pal_fn, args = list()),
     error = function(e) {
       cli::cli_abort("Unable to locate the requested pal.")
     }
   )
+
+  invisible()
 }
 
 .pal_app <- function() {
@@ -17,9 +26,14 @@
   ui <- miniUI::miniPage(
     miniUI::miniContentPanel(
       shiny::selectizeInput("pal", "Select a pal:",
-                            choices = NULL,
-                            selected = NULL,
-                            multiple = FALSE
+                            choices = pal_choices,
+                            multiple = FALSE,
+                            options = list(
+                              create = FALSE,
+                              placeholder = 'Type to filter or select a pal',
+                              onDropdownOpen = I("function($dropdown) {this.clear();}"),
+                              onBlur = I("function() {this.clear();}")
+                            )
       ),
       shiny::verbatimTextOutput("result"),
       shiny::tags$script(shiny::HTML("
@@ -28,16 +42,16 @@
             Shiny.setInputValue('done', true, {priority: 'event'});
           }
         });
+        $(document).ready(function() {
+          setTimeout(function() {
+            $('.selectize-input input').focus();
+          }, 100);
+        });
       "))
     )
   )
 
   server <- function(input, output, session) {
-    shiny::updateSelectizeInput(
-      session, 'pal',
-      choices = pal_choices,
-      server = TRUE
-    )
     shiny::observeEvent(input$done, {
       shiny::stopApp(returnValue = paste0(".pal_rs__", input$pal))
     })