FIX: better solution for setting a required field for send_message

assets/javascripts/discourse/templates/components/wizard-custom-action.hbs

@@ -143,6 +143,17 @@
 {{/if}}
 
 {{#if sendMessage}}
+  <div class="setting">
+    <div class="setting-label">
+      <h3>{{i18n 'admin.wizard.required'}}</h3>
+    </div>
+    <div class="setting-value">
+      {{combo-box content=availableFields
+                  nameProperty='label'
+                  none='admin.wizard.select_field'
+                  value=action.required}}
+    </div>
+  </div>
   <div class="setting">
     <div class="setting-label">
       <h3>{{i18n "admin.wizard.action.send_message.recipient"}}</h3>

lib/builder.rb

@@ -423,15 +423,9 @@ class CustomWizard::Builder
 
   def send_message(user, action, data)
 
-    empty_data = false
-
-    data.each do |k, v|
-      if v.empty?
-        empty_data = true
+    if action['required'].present? && data[action['required']].blank?
+      return
     end
-    end
-    # leave if there are any empty fields
-    return if empty_data
     
     if action['custom_title_enabled']
       title = CustomWizard::Builder.fill_placeholders(action['custom_title'], user, data)