Custom scopes for paginated lists

app/controllers/asciicasts_controller.rb

@@ -9,27 +9,21 @@ class AsciicastsController < ApplicationController
   respond_to :html, :json
 
   def index
-    collection = Asciicast.
-      newest.
-      includes(:user).
-      page(params[:page]).
-      per(PER_PAGE)
+    @asciicasts = AsciicastDecorator.decorate(
+      Asciicast.newest_paginated(params[:page], PER_PAGE)
+    )
 
     @category_name = "All Asciicasts"
     @current_category = :all
-    @asciicasts = AsciicastDecorator.decorate(collection)
   end
 
   def popular
-    collection = Asciicast.
-      popular.
-      includes(:user).
-      page(params[:page]).
-      per(PER_PAGE)
+    @asciicasts = AsciicastDecorator.decorate(
+      Asciicast.popular_paginated(params[:page], PER_PAGE)
+    )
 
     @category_name = "Popular Asciicasts"
     @current_category = :popular
-    @asciicasts = AsciicastDecorator.decorate(collection)
 
     render :index
   end

app/models/asciicast.rb

@@ -15,6 +15,14 @@ class Asciicast < ActiveRecord::Base
   scope :popular, where("views_count > 0").order("views_count DESC")
   scope :newest, order("created_at DESC")
 
+  scope(:newest_paginated, lambda do |page, per_page|
+    newest.includes(:user).page(page).per(per_page)
+  end)
+
+  scope(:popular_paginated, lambda do |page, per_page|
+    popular.includes(:user).page(page).per(per_page)
+  end)
+
   before_create :assign_user, :unless => :user
 
   attr_accessible :meta, :stdout, :stdout_timing, :stdin, :stdin_timing,