order comments by the most recent first

app/controllers/debates_controller.rb

@@ -4,11 +4,11 @@ class DebatesController < ApplicationController
 
   def index
     if params[:tag]
-      @debates = Debate.tagged_with(params[:tag]).order("created_at DESC")
-      set_voted_values @debates.map(&:id)
+      @debates = Debate.tagged_with(params[:tag]).order(id: :desc)
+      set_voted_values @debates.pluck(:id)
     else
-      @debates = Debate.all.order("created_at DESC")
-      set_voted_values @debates.map(&:id)
+      @debates = Debate.all.order(id: :desc)
+      set_voted_values @debates.pluck(:id)
     end
   end
 

app/models/comment.rb

@@ -8,6 +8,8 @@ class Comment < ActiveRecord::Base
   belongs_to :commentable, polymorphic: true
   belongs_to :user
 
+  scope :recent, -> { order(id: :desc) }
+
   def self.build(commentable, user, body)
     new commentable: commentable,
         user_id:     user.id,

app/views/comments/_comment.html.erb

@@ -22,8 +22,8 @@
     </div>
 
     <div class="comment-children">
-      <%= render comment.children %>
+      <%= render comment.children.reorder('id DESC, lft') %>
     </div>
 
   </div>
-</div>
+</div>

app/views/debates/_debate.html.erb

@@ -25,4 +25,4 @@
 
     </div>
   </div>
-</div>
+</div>

app/views/debates/show.html.erb

@@ -43,10 +43,10 @@
           <%= render 'comments/form', {parent: @debate, toggeable: false} %>
         </div>
       <% end %>
-      <%= render @debate.root_comments %>
+      <%= render @debate.root_comments.recent %>
     </div>
     <% if current_user && @debate.editable_by?(current_user) %>
       <%= link_to t("debates.show.edit_debate_link"), edit_debate_path(@debate), :class => 'button radius right' %>
     <% end %>
   </div>
-</section>
+</section>