Fix custom selectize rendering

Fixes #2192. Two problems here:

1. It's not documented but apparently we supported data frames for
   choices in updateSelectInput/updateSelectizeInput (it doesn't
   appear to work correctly for selectInput/selectizeInput though).
   This was used in 023-optgroup-server as well as by the user who
   reported #2172.
2. The example in 023-optgroup-server was also counting on the
   default value of optgroupLabelField, which (starting post-Shiny
   v1.1) was being set to a new default of "group". That now won't
   happen unless optgroupField is also blank. I'm less confident
   about the ramifications of this change. The selectize docs with
   the relevant bits are here:
  https://github.com/selectize/selectize.js/blob/master/docs/usage.md#data_searching

R/update-input.R

@@ -654,7 +654,14 @@ updateSelectizeInput <- function(session, inputId, label = NULL, choices = NULL,
     }
   }
   # convert choices to a data frame so it returns [{label: , value: , group: },...]
-  choices <- if (is.atomic(choices) || noOptGroup) {
+  choices <- if (is.data.frame(choices)) {
+    # jcheng 2018/09/25: I don't think we ever said data frames were OK to pass
+    # to updateSelectInput, but one of the example apps does this and at least
+    # one user noticed when we broke it.
+    # https://github.com/rstudio/shiny/issues/2172
+    # https://github.com/rstudio/shiny/issues/2192
+    as.data.frame(choices, stringsAsFactors = FALSE)
+  } else if (is.atomic(choices) || noOptGroup) {
     # fast path for vectors and flat lists
     if (is.list(choices)) {
       choices <- unlist(choices)

inst/www/shared/shiny.js

@@ -5401,14 +5401,25 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
       var $el = $(el);
       var config = $el.parent().find('script[data-for="' + $escape(el.id) + '"]');
       if (config.length === 0) return undefined;
+
       var options = $.extend({
         labelField: 'label',
         valueField: 'value',
-        searchField: ['label'],
-        optgroupField: 'group',
-        optgroupLabelField: 'group',
-        optgroupValueField: 'group'
+        searchField: ['label']
       }, JSON.parse(config.html()));
+
+      if (!options.optgroupField) {
+        // We set the defaults for optgroupField separately from the other
+        // defaults, because if optgroupField was explicitly provided then we
+        // don't want to default optgroupLabelField and optgroupValueField.
+        // https://github.com/rstudio/shiny/issues/2192
+        options = $.extend({
+          optgroupField: 'group',
+          optgroupLabelField: 'group',
+          optgroupValueField: 'group'
+        }, options);
+      }
+
       // selectize created from selectInput()
       if (typeof config.data('nonempty') !== 'undefined') {
         el.nonempty = true;

srcjs/input_binding_select.js

@@ -138,14 +138,25 @@ $.extend(selectInputBinding, {
     var $el = $(el);
     var config = $el.parent().find('script[data-for="' + $escape(el.id) + '"]');
     if (config.length === 0) return undefined;
+
     var options = $.extend({
       labelField: 'label',
       valueField: 'value',
-      searchField: ['label'],
-      optgroupField: 'group',
-      optgroupLabelField: 'group',
-      optgroupValueField: 'group'
+      searchField: ['label']
     }, JSON.parse(config.html()));
+
+    if (!options.optgroupField) {
+      // We set the defaults for optgroupField separately from the other
+      // defaults, because if optgroupField was explicitly provided then we
+      // don't want to default optgroupLabelField and optgroupValueField.
+      // https://github.com/rstudio/shiny/issues/2192
+      options = $.extend({
+        optgroupField: 'group',
+        optgroupLabelField: 'group',
+        optgroupValueField: 'group'
+      }, options);
+    }
+
     // selectize created from selectInput()
     if (typeof(config.data('nonempty')) !== 'undefined') {
       el.nonempty = true;