Server-side render initial visibility of select help text

Resolves failure to display initial help text of difficulty level.

app/assets/javascripts/osem.js

@@ -145,7 +145,7 @@ function word_count(text, divId, maxcount) {
 /* Wait for the DOM to be ready before attaching events to the elements */
 $( document ).ready(function() {
     /* Set the minimum and maximum proposal abstract word length */
-    $("#event_event_type_id").change(function () {
+    function updateEventTypeRequirements() {
         var $selected = $("#event_event_type_id option:selected")
         var max = $selected.data("max-words");
         var min = $selected.data("min-words");
@@ -153,8 +153,9 @@ $( document ).ready(function() {
         $("#abstract-maximum-word-count").text(max);
         $("#abstract-minimum-word-count").text(min);
         word_count($('#event_abstract').get(0), 'abstract-count', max);
-    })
-        .trigger('change');
+    }
+    $("#event_event_type_id").change(updateEventTypeRequirements);
+    updateEventTypeRequirements();
 
     /* Count the proposal abstract length */
     $("#event_abstract").on('input', function() {

app/views/proposals/_form.html.haml

@@ -27,16 +27,14 @@
   .form-group
   = f.label :language
   = f.select :language, @languages, { include_blank: false}, { class: 'select-help-toggle form-control' }
-- @conference.program.event_types.each do |event_type|
-  %span{ class: 'help-block select-help-text event_event_type_id collapse', id: "#{event_type.id}-help" }
-    = event_type.description
+= render 'shared/select_help_text', f: f, for: :event_type_id, options: @conference.program.event_types do |event_type|
+  = event_type.description
 - if action_is_edit
   - if @conference.program.difficulty_levels.any?
     = f.label :difficulty_level
     = f.select :difficulty_level_id, @conference.program.difficulty_levels.map{|level| [level.title, level.id ] }, {include_blank: false}, { class: 'select-help-toggle form-control' }
-    - @conference.program.difficulty_levels.each do |difficulty_level|
-      %span{ class: 'help-block select-help-text collapse event_difficulty_level_id', id: "#{difficulty_level.id}-help" }
-        = difficulty_level.description
+    = render 'shared/select_help_text', f: f, for: :difficulty_level_id, options: @conference.program.difficulty_levels do |difficulty_level|
+      = difficulty_level.description
 .form-group
   = f.label :abstract
   = f.text_area :abstract, required: true, rows: 5, data: { provide: 'markdown' }, class: 'form-control'

app/views/shared/_select_help_text.html.haml

@@ -0,0 +1,10 @@
+:ruby
+  include_blank ||= false
+  select_id = field_id(f.object_name, local_assigns[:for])
+  value = f.object.send(local_assigns[:for])
+
+- options.each_with_index do |option, i|
+  - selected = value.present? ? option.id == value : !include_blank && i == 0
+
+  %span.help-block.select-help-text.collapse{ id: "#{option.id}-help", class: [select_id, ('in' if selected)] }
+    = yield option