Event form: change code that updates CoC URL to fetch it over ajax

Also fixes a bug where the CoC URL would be inaccurately set back
to the default URL when you 'save draft' or the like.

app/controllers/chapters_controller.rb

@@ -64,6 +64,11 @@ def destroy
     redirect_to chapters_url
   end
 
+  def code_of_conduct_url
+    skip_authorization
+    render text: @chapter.code_of_conduct_url
+  end
+
   private
 
   def chapter_params

app/models/chapter.rb

@@ -22,4 +22,8 @@ def has_leader?(user)
   def destroyable?
     (events_count + external_events_count) == 0
   end
+
+  def code_of_conduct_url
+    organization.code_of_conduct_url || Event::DEFAULT_CODE_OF_CONDUCT_URL
+  end
 end

app/models/event.rb

@@ -366,6 +366,10 @@ def levels
     course[:levels]
   end
 
+  def code_of_conduct_url
+    chapter.try(:code_of_conduct_url) || DEFAULT_CODE_OF_CONDUCT_URL
+  end
+
   private
 
   DEFAULT_DETAIL_FILES = Dir[Rails.root.join('app', 'models', 'event_details', '*.html')]

app/views/events/_form.html.erb

@@ -264,12 +264,12 @@
     <div class="field">
       <script>
         window.whenReady(function () {
-          var chapterOrganization = <%= Chapter.all.each_with_object({}) { |c, hsh| hsh[c.id] = c.organization_id }.to_json.html_safe %>;
-          var organizationCoc = <%= Organization.where.not(code_of_conduct_url: nil).each_with_object({}) { |o, hsh| hsh[o.id] = o.code_of_conduct_url }.to_json.html_safe %>;
           $('#event_chapter_id').on('change', function () {
             var chapterId = parseInt(this.value, 10);
-            $('#coc_url').attr('href', organizationCoc[chapterOrganization[chapterId]] || '<%= Event::DEFAULT_CODE_OF_CONDUCT_URL %>');
             $('#coc').attr('checked', false);
+            $.get("/chapters/" + chapterId + "/code_of_conduct_url").then(function (codeOfConductUrl) {
+              $('#coc_url').attr('href', codeOfConductUrl);
+            });
           });
         });
       </script>
@@ -279,7 +279,7 @@
           'toggle-target' => '.coc-required',
           'toggle-enable-when-checked' => true
         } %>
-          I accept the <%= link_to 'Code of Conduct', Event::DEFAULT_CODE_OF_CONDUCT_URL, target: :blank, id: 'coc_url' %> and will communicate it at the beginning of the event.
+          I accept the <%= link_to 'Code of Conduct', @event.code_of_conduct_url, target: :blank, id: 'coc_url' %> and will communicate it at the beginning of the event.
         </strong>
       <% end %>
     </div>

config/routes.rb

@@ -20,6 +20,10 @@
     resources :leaders, only: [:index, :create, :destroy], controller: 'chapters/leaders' do
       get :potential, on: :collection
     end
+
+    member do
+      get :code_of_conduct_url
+    end
   end
 
   resources :regions do