UX: Wiggle invalid form elements. Don't allow a site title of Discourse

app/assets/javascripts/wizard/components/wizard-step.js.es6

@@ -1,5 +1,16 @@
 import { default as computed, observes } from 'ember-addons/ember-computed-decorators';
 
+jQuery.fn.wiggle = function (times, duration) {
+  if (times > 0) {
+    this.animate({
+      marginLeft: times-- % 2 === 0 ? -15 : 15
+    }, duration, 0, () => this.wiggle(times, duration));
+  } else {
+    this.animate({ marginLeft: 0 }, duration, 0);
+  }
+  return this;
+};
+
 export default Ember.Component.extend({
   classNames: ['wizard-step'],
   saving: null,
@@ -51,6 +62,10 @@ export default Ember.Component.extend({
     });
   },
 
+  animateInvalidFields() {
+    Ember.run.scheduleOnce('afterRender', () => $('.invalid input[type=text]').wiggle(2, 100));
+  },
+
   actions: {
     quit() {
       document.location = "/";
@@ -71,9 +86,10 @@ export default Ember.Component.extend({
         this.set('saving', true);
         step.save()
           .then(response => this.sendAction('goNext', response))
-          .catch(() => null) // we can swallow because the form is already marked as invalid
+          .catch(() => this.animateInvalidFields()) 
           .finally(() => this.set('saving', false));
       } else {
+        this.animateInvalidFields();
         this.autoFocus();
       }
     }

lib/wizard/builder.rb

@@ -30,7 +30,11 @@ class Wizard
         step.add_field(id: 'site_description', type: 'text', required: true, value: SiteSetting.site_description)
 
         step.on_update do |updater|
-          updater.apply_settings(:title, :site_description)
+          updater.ensure_changed(:title)
+
+          if updater.errors.blank?
+            updater.apply_settings(:title, :site_description)
+          end
         end
       end
 

lib/wizard/step_updater.rb

@@ -39,6 +39,10 @@ class Wizard
       errors.add(id, e.message)
     end
 
+    def ensure_changed(id)
+      errors.add(id, '') if @fields[id] == SiteSetting.defaults[id]
+    end
+
     def apply_settings(*ids)
       ids.each {|id| apply_setting(id)}
     end

spec/components/step_updater_spec.rb

@@ -38,6 +38,13 @@ describe Wizard::StepUpdater do
     expect(wizard.completed_steps?('forum-title')).to eq(true)
   end
 
+  it "won't allow updates to the default value, when required" do
+    updater = wizard.create_updater('forum_title', title: SiteSetting.title, site_description: 'neat place')
+    updater.update
+
+    expect(updater.success?).to eq(false)
+  end
+
   context "privacy settings" do
     it "updates to open correctly" do
       updater = wizard.create_updater('privacy', privacy: 'open')