use thumbs_up

Gemfile

@@ -12,6 +12,8 @@ gem 'sqlite3'
 
 gem 'ampex'
 
+gem 'thumbs_up', :git => "git@github.com:dementrock/thumbs_up.git"
+
 group :test do
   gem 'rspec'
   gem 'rack-test', :require => "rack/test"

app.rb

@@ -2,10 +2,12 @@ require 'rubygems'
 require 'yajl'
 require 'active_record'
 require 'sinatra'
+require 'thumbs_up'
 
 require_relative 'models/comment'
 require_relative 'models/comment_thread'
 require_relative 'models/vote'
+require_relative 'models/user'
 
 env_index = ARGV.index("-e")
 env_arg = ARGV[env_index + 1] if env_index
@@ -103,11 +105,12 @@ put '/api/v1/votes/comments/:comment_id/users/:user_id' do |comment_id, user_id|
     if comment.nil?
       error 400, {:error => "invalid comment id"}.to_json
     else
-      vote = Vote.create_or_update :user_id => user_id, :comment_id => comment_id, :value => params["value"]
-      if vote
+      if %w[up down].include? params["value"]
+        user = User.find_or_create_by_id(user_id)
+        vote = user.vote(comment, { :direction => (params["value"] == "up" ? :up : :down ), :exclusive => :true})
         vote.to_json
       else
-        error 400, vote.errors.to_json
+        error 400, {:error => "value must be up or down"}
       end
     end
   end
@@ -115,12 +118,13 @@ end
 
 # undo the vote on the comment by the user
 delete '/api/v1/votes/comments/:comment_id/users/:user_id' do |comment_id, user_id|
-  vote = Vote.find_by_comment_id_and_user_id(comment_id, user_id)
-  if vote.nil?
-    error 400, {:error => "vote does not exist"}.to_json
-  else
-    vote.destroy
+  user = User.find_by_id(user_id.to_i)
+  comment = Comment.find_by_id(comment_id)
+  if user and comment and not comment.is_root?
+    vote = user.unvote_for(comment)
     vote.to_json
+  else
+    error 400, {:error => "invalid user or comment id"}
   end
 end
 

db/migrate/003_create_users.rb

+class CreateUsers < ActiveRecord::Migration
+  def self.up
+    create_table :users do |t|
+    end
+  end
+
+  def self.down
+    drop_table :users
+  end
+end

db/migrate/003_create_votes.rb → db/migrate/004_create_votes.rb

 class CreateVotes < ActiveRecord::Migration
   def self.up
-    create_table :votes do |t|
-      t.integer :user_id
-      t.integer :comment_id
-      t.string  :value
+    create_table :votes, :force => true do |t|
+      
+      t.boolean    :vote,     :default => false
+      t.references :voteable, :polymorphic => true, :null => false
+      t.references :voter,    :polymorphic => true
       t.timestamps
+      
     end
 
-    add_index :votes, :comment_id
-    add_index :votes, :user_id
-    add_index :votes, [:comment_id, :user_id]
+    add_index :votes, [:voter_id, :voter_type]
+    add_index :votes, [:voteable_id, :voteable_type]
+
+    add_index :votes, [:voter_id, :voter_type, :voteable_id, :voteable_type], :unique => true, :name => 'fk_one_vote_per_user_per_entity'
   end
 
   def self.down
     drop_table :votes
   end
+
 end

models/comment.rb

 require 'active_record'
 require 'ancestry'
+require 'thumbs_up'
 
 class Comment < ActiveRecord::Base
 
@@ -7,10 +8,10 @@ class Comment < ActiveRecord::Base
 
   has_ancestry
 
-  has_many :votes
-
   belongs_to :comment_thread
 
+  acts_as_voteable
+
   validates_presence_of :body, :unless => :is_root?
   validates_presence_of :user_id, :unless => :is_root?
   validates_presence_of :course_id, :unless => :is_root?
@@ -25,7 +26,7 @@ class Comment < ActiveRecord::Base
   end
 
   def to_hash
-    attributes.merge(:votes => {:up => Vote.comment_id(id).up.count, :down => Vote.comment_id(id).down.count})
+    attributes.merge(:votes => {:up => votes_for, :down => votes_against})
   end
 
   def to_json

models/user.rb

+require 'active_record'
+require 'thumbs_up'
+
+class User < ActiveRecord::Base
+  acts_as_voter
+
+end

models/vote.rb

 require 'active_record'
 
-# Adapted from "Service-Oriented Design with Ruby and Rails"
 class Vote < ActiveRecord::Base
 
-  attr_accessible :value, :user_id, :comment_id
-  
-  belongs_to :comment
+  scope :for_voter, lambda { |*args| where(["voter_id = ? AND voter_type = ?", args.first.id, args.first.class.base_class.name]) }
+  scope :for_voteable, lambda { |*args| where(["voteable_id = ? AND voteable_type = ?", args.first.id, args.first.class.base_class.name]) }
+  scope :recent, lambda { |*args| where(["created_at > ?", (args.first || 2.weeks.ago)]) }
+  scope :descending, order("created_at DESC")
 
-  validates_inclusion_of :value, :in => %w{up down}
-  validates_uniqueness_of :user_id, :scope => :comment_id
-  validates_presence_of :comment_id, :user_id
+  belongs_to :voteable, :polymorphic => true
+  belongs_to :voter, :polymorphic => true
 
-  scope :up, :conditions => ["value = ?", "up"]
-  scope :down, :conditions => ["value = ?", "down"]
-  scope :user_id, lambda {|user_id| {:conditions => ["user_id = ?", user_id]}}
-  scope :comment_id, lambda {|comment_id| {:conditions => ["comment_id = ?", comment_id]}}
+  attr_accessible :vote, :voter, :voteable
 
-  def self.create_or_update(attributes)
-    vote = Vote.find_by_comment_id_and_user_id(attributes[:comment_id], attributes[:user_id])
-    if vote
-      vote.value = attributes[:value]
-      vote.save
-      vote
-    else
-      Vote.create(attributes)
-    end
-  end
-  
+  # Comment out the line below to allow multiple votes per user.
+  validates_uniqueness_of :voteable_id, :scope => [:voteable_type, :voter_type, :voter_id]
 end

spec/app_spec.rb

@@ -69,13 +69,14 @@ describe "app" do
         comment << (comment_thread.root_comments.create :body => "top comment", :title => "top 0", :user_id => 1, :course_id => 1, :comment_thread_id => comment_thread.id)
         sub_comment << (comment[0].children.create :body => "comment body", :title => "comment title 0", :user_id => 1, :course_id => 1, :comment_thread_id => comment_thread.id)
         sub_comment << (comment[0].children.create :body => "comment body", :title => "comment title 1", :user_id => 1, :course_id => 1, :comment_thread_id => comment_thread.id)
-        Vote.create! :value => "up", :comment_id => comment[0].id, :user_id => 1
-        Vote.create! :value => "up", :comment_id => comment[0].id, :user_id => 2
-        Vote.create! :value => "up", :comment_id => comment[0].id, :user_id => 3
-        Vote.create! :value => "up", :comment_id => comment[0].id, :user_id => 4
-        Vote.create! :value => "down", :comment_id => comment[0].id, :user_id => 5
-        Vote.create! :value => "down", :comment_id => comment[0].id, :user_id => 6
-        Vote.create! :value => "down", :comment_id => comment[0].id, :user_id => 7
+        (1..4).each do |id|
+          user = User.find_or_create_by_id(id)
+          user.vote_for(comment[0])
+        end
+        (5..7).each do |id|
+          user = User.find_or_create_by_id(id)
+          user.vote_against(comment[0])
+        end
         get "/api/v1/commentables/questions/1/comments"
         last_response.should be_ok
         comments = Yajl::Parser.parse last_response.body
@@ -196,16 +197,18 @@ describe "app" do
         comment = CommentThread.first.root_comments.create :body => "top comment", :title => "top", :user_id => 1, :course_id => 1
         comment.comment_thread = comment_thread
         comment.save!
+        Vote.delete_all
       end
       it "votes up on a comment" do
         comment = CommentThread.first.comments.first
         put "/api/v1/votes/comments/#{comment.id}/users/1", :value => "up"
         last_response.should be_ok
         vote = Vote.first
+        puts vote
         vote.should_not be_nil
-        vote.user_id.should == 1
-        vote.comment_id.should == comment.id
-        vote.value.should == "up"
+        vote.voter_id.should == 1
+        vote.voteable_id.should == comment.id
+        vote.vote.should be_true
       end
       it "votes down on a comment" do
         comment = CommentThread.first.comments.first
@@ -213,9 +216,10 @@ describe "app" do
         last_response.should be_ok
         vote = Vote.first
         vote.should_not be_nil
-        vote.user_id.should == 1
-        vote.comment_id.should == comment.id
-        vote.value.should == "down"
+        vote.voter_id.should == 1
+        vote.voteable_id.should == comment.id
+        vote.vote.should be_false
+        
       end
       it "rejects invalid vote value" do
         comment = CommentThread.first.comments.first
@@ -229,10 +233,11 @@ describe "app" do
       end
       it "change vote on comment" do
         comment = CommentThread.first.comments.first
-        Vote.create! :value => "up", :user_id => 1, :comment_id => comment.id
+        user = User.find_or_create_by_id(1)
+        user.vote_for(comment)
         put "/api/v1/votes/comments/#{comment.id}/users/1", :value => "down"
         last_response.should be_ok
-        Vote.first.value.should == "down"
+        Vote.first.vote.should be_false
       end
     end
     describe "DELETE on /api/v1/votes/comments/:comment_id/users/:user_id" do
@@ -242,15 +247,16 @@ describe "app" do
       end
       it "deletes vote" do
         comment = CommentThread.first.comments.first 
-        Vote.create! :value => "up", :user_id => 1, :comment_id => comment.id
+        user = User.find_or_create_by_id(1)
+        user.vote_for(comment)
         delete "/api/v1/votes/comments/#{comment.id}/users/1"
         last_response.should be_ok
         Vote.count.should == 0
       end
-      it "returns 400 for nonexisted vote" do
+      it "does nothing for nonexisted vote" do
         comment = CommentThread.first.comments.first 
         delete "/api/v1/votes/comments/#{comment.id}/users/1"
-        last_response.status.should == 400
+        last_response.should be_ok
       end
     end
   end