From 8bb553701aca3e293e8f443cce58b294764ef8e1 Mon Sep 17 00:00:00 2001
From: Matchu <matchu1993@gmail.com>
Date: Fri, 25 Jan 2013 15:23:48 -0600
Subject: [PATCH] remove N+1 queries in contributions#index

---
 app/controllers/contributions_controller.rb |  9 ++++++++-
 app/models/contribution.rb                  | 17 +++++++----------
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/app/controllers/contributions_controller.rb b/app/controllers/contributions_controller.rb
index 20a4f8e9..2d37be10 100644
--- a/app/controllers/contributions_controller.rb
+++ b/app/controllers/contributions_controller.rb
@@ -7,6 +7,13 @@ class ContributionsController < ApplicationController
       @contributions = Contribution.includes(:user)
     end
     @contributions = @contributions.recent.paginate :page => params[:page]
-    Contribution.preload_contributeds_and_parents @contributions
+    Contribution.preload_contributeds_and_parents(
+      @contributions,
+      :scopes => {
+        'Item' => Item.includes(:translations),
+        'PetType' => PetType.includes({:species => :translations,
+                                       :color => :translations})
+      }
+    )
   end
 end
diff --git a/app/models/contribution.rb b/app/models/contribution.rb
index 648be077..6ce7d4f1 100644
--- a/app/models/contribution.rb
+++ b/app/models/contribution.rb
@@ -26,12 +26,9 @@ class Contribution < ActiveRecord::Base
   }
   CONTRIBUTED_CHILDREN = CONTRIBUTED_RELATIONSHIPS.keys
   CONTRIBUTED_TYPES = CONTRIBUTED_CHILDREN + CONTRIBUTED_RELATIONSHIPS.values
-  CONTRIBUTED_BASES = {}
-  CONTRIBUTED_TYPES.each do |type|
-    base = type == 'SwfAsset' ? SwfAsset.object_assets : type.constantize
-    CONTRIBUTED_BASES[type] = base
-  end
-  def self.preload_contributeds_and_parents(contributions)
+  def self.preload_contributeds_and_parents(contributions, options={})
+    options[:scopes] ||= {}
+    
     # Initialize the groups we'll be using for quick access
     contributions_by_type = {}
     contributed_by_type = {}
@@ -56,8 +53,8 @@ class Contribution < ActiveRecord::Base
     # Load contributed objects without parents, prepare them for easy access
     # for future assignment to contributions and looking up parents
     CONTRIBUTED_CHILDREN.each do |type|
-      base = CONTRIBUTED_BASES[type]
-      base.find(needed_ids_by_type[type]).each do |contributed|
+      scope = options[:scopes][type] || type.constantize.scoped
+      scope.find(needed_ids_by_type[type]).each do |contributed|
         contributed_by_type[type] << contributed
         contributed_by_type_and_id[type][contributed.id] = contributed
       end
@@ -67,10 +64,10 @@ class Contribution < ActiveRecord::Base
     # contributed objects of that class. all_by_ids_or_children properly
     # assigns parents to children, as well
     CONTRIBUTED_RELATIONSHIPS.each do |child_type, type|
-      base = CONTRIBUTED_BASES[type]
+      scope = options[:scopes][type] || type.constantize.scoped
       ids = needed_ids_by_type[type]
       children = contributed_by_type[child_type]
-      base.all_by_ids_or_children(ids, children).each do |contributed|
+      scope.all_by_ids_or_children(ids, children).each do |contributed|
         contributed_by_type_and_id[type][contributed.id] = contributed
       end
     end