Add a feature to send likes for ideas

app/assets/stylesheets/welcome.css.scss

@@ -1,3 +1,14 @@
 // Place all the styles related to the welcome controller here.
 // They will automatically be included in application.css.
 // You can use Sass (SCSS) here: http://sass-lang.com/
+.likeLink {
+  float: right;
+}
+
+.ideaLink {
+  float: left;
+}
+
+.list-group-item {
+  clear: both;
+}

app/controllers/ideas_controller.rb

@@ -1,9 +1,9 @@
 # -*- coding: utf-8 -*-
 class IdeasController < ApplicationController
   before_action :authenticate, except: :show
+  before_action :find_idea, only: [:show, :like, :dislike]
 
   def show
-    @idea = Idea.find(params[:id])
     @comments = @idea.comments
     @comment = Comment.new
   end
@@ -18,4 +18,22 @@ def create
       render 'welcome/index'
     end
   end
+
+  # PUT /like/1
+  def like
+    current_user.like @idea
+
+    redirect_to root_path, notice: 'いいね！しました。'
+  end
+
+  def dislike
+    current_user.dislike @idea
+
+    redirect_to root_path
+  end
+
+  private
+  def find_idea
+    @idea = Idea.find(params[:id])
+  end
 end

app/models/comment.rb

@@ -1,6 +1,7 @@
 class Comment < ActiveRecord::Base
   belongs_to :idea
   belongs_to :user
+  has_many :likes, as: :likeable
 
   validates :body, length: { maximum: 1000 }, presence: true
 end

app/models/idea.rb

@@ -1,6 +1,7 @@
 class Idea < ActiveRecord::Base
   has_many :comments
   belongs_to :user
+  has_many :likes, as: :likeable
 
   validates :title, length: { maximum: 100 }, presence: true
 end

app/models/like.rb

@@ -0,0 +1,6 @@
+class Like < ActiveRecord::Base
+  belongs_to :user
+  belongs_to :likeable, polymorphic: true
+
+  validates :user_id, uniqueness: {scope: [:likeable_id, :likeable_type]}
+end

app/models/user.rb

@@ -12,4 +12,18 @@ def self.find_or_create_from_auth_hash(auth_hash)
       user.image_url = image_url
     end
   end
+
+  def like(idea)
+    idea.likes.create!(user_id: id)
+  end
+
+  def dislike(idea)
+    like = idea.likes.where(user_id: id).first
+    raise ActiveRecord::RecordNotFound if like.nil?
+    like.destroy
+  end
+
+  def liked?(idea)
+    idea.likes.where(user_id: id).count > 0
+  end
 end

app/views/welcome/index.html.haml

@@ -23,9 +23,16 @@
 .list-group
   - @ideas.each do |idea|
     .list-group-item
+      .ideaLink
       = link_to idea do
         - if idea.user.try(:image_url)
           = image_tag(idea.user.image_url, width: 30, height: 30, alt: idea.user.nickname, title: idea.user.nickname).html_safe
-          = idea.title
-        - else
-          = idea.title
+        = idea.title
+      = "(#{idea.likes.count} いいね！)"
+
+      .likeLink
+        - if current_user
+          - if current_user.liked?(idea) 
+            = link_to 'いいね！を取り消す', dislike_idea_path(idea), class: 'dislike', method: :put
+          - else
+            = link_to 'いいね！', like_idea_path(idea), class: 'like', method: :put

config/routes.rb

@@ -5,6 +5,10 @@
   get '/logout' => 'sessions#destroy', as: :logout
 
   resources :ideas, only: [:show, :create] do
+    member do 
+      put :like
+      put :dislike
+    end
     resources :comments, only: :create
   end
 

db/migrate/20140520051103_create_likes.rb

@@ -0,0 +1,14 @@
+class CreateLikes < ActiveRecord::Migration
+  def change
+    create_table :likes do |t|
+      t.integer :likeable_id
+      t.string :likeable_type
+      t.belongs_to :user, index: true
+
+      t.timestamps
+    end
+
+    add_index :likes, [:likeable_id, :likeable_type]
+    add_index :likes, [:likeable_id, :likeable_type, :user_id], unique: true
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20140427143623) do
+ActiveRecord::Schema.define(version: 20140520051103) do
 
   create_table "comments", force: true do |t|
     t.integer  "idea_id"
@@ -33,6 +33,18 @@
 
   add_index "ideas", ["user_id"], name: "index_ideas_on_user_id"
 
+  create_table "likes", force: true do |t|
+    t.integer  "likeable_id"
+    t.string   "likeable_type"
+    t.integer  "user_id"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
+  add_index "likes", ["likeable_id", "likeable_type", "user_id"], name: "index_likes_on_likeable_id_and_likeable_type_and_user_id", unique: true
+  add_index "likes", ["likeable_id", "likeable_type"], name: "index_likes_on_likeable_id_and_likeable_type"
+  add_index "likes", ["user_id"], name: "index_likes_on_user_id"
+
   create_table "users", force: true do |t|
     t.string   "provider",   null: false
     t.string   "uid",        null: false

spec/factories/likes.rb

@@ -0,0 +1,9 @@
+# Read about factories at https://github.com/thoughtbot/factory_girl
+
+FactoryGirl.define do
+  factory :like do
+    likeable_id 1
+    likeable_type "MyString"
+    user nil
+  end
+end

spec/features/like_idea_spec.rb

@@ -0,0 +1,49 @@
+# -*- coding: utf-8 -*-
+require 'spec_helper'
+
+describe 'アイデアに「いいね！」を付けられるようにする' do
+  let(:idea) { create :idea }
+
+  context '未ログイン状態でトップページにアクセスしたとき' do
+    before { visit root_path(idea) }
+
+    it 'いいね！用のリンクが表示されていないこと' do
+      expect(page).to have_no_css 'a.like'
+    end
+  end
+
+  context 'ログイン状態でトップページにアクセスしたとき' do
+    before do
+      idea
+      login
+      visit root_path
+    end
+
+    context 'いいね！を付ける前のとき' do
+      it 'いいね！用のリンクが表示されていること' do
+        expect(page).to have_css 'a.like'
+      end
+    end
+
+    context 'いいね！ボタンを押したとき' do
+      before do
+        click_link 'いいね！'
+      end
+
+      it '"いいね！を取り消す"と表示されていること' do
+        expect(page).to have_css 'a.dislike'
+      end
+
+      it '"いいね！"した人の数が表示されていること' do
+        expect(page).to have_content "(1 いいね！)"
+      end
+
+      it '"いいね！"を取り消すことができること' do
+        click_link 'いいね！を取り消す'
+        expect(page).to have_content "(0 いいね！)"
+        expect(page).to have_css 'a.like'
+      end
+    end
+
+  end
+end

spec/models/like_spec.rb

@@ -0,0 +1,6 @@
+require 'spec_helper'
+
+describe Like do
+  it { should belong_to(:user) }
+  it { should belong_to(:likeable) }
+end

spec/models/user_spec.rb

@@ -46,4 +46,79 @@
       end
     end
   end
+
+  describe '#like' do
+    let!(:user) { create :user, provider: 'twitter', uid: 'uid' }
+    let!(:comment) { create :comment }
+    let(:idea) { comment.idea }
+
+    context "アイデアに対して" do
+      it 'いいね！をするとlikeが増える' do
+        expect {
+          user.like(idea)
+        }.to change(idea.likes, :count).by(1)
+      end
+    end
+
+    context "コメントに対して" do
+      it 'いいね！をするとlikeが増える' do
+        expect {
+          user.like(comment)
+        }.to change(comment.likes, :count).by(1)
+      end
+    end
+  end
+
+  describe "#dislike" do
+    let!(:user) { create :user, provider: 'twitter', uid: 'uid' }
+    let!(:comment) { create :comment }
+    let(:idea) { comment.idea }
+
+    context "アイデアに対して" do
+      context "すでにいいね！している場合" do
+        before do
+          user.like(idea)
+        end
+
+        it 'いいね！を取り消すとlikeが減る' do
+          expect {
+            user.dislike(idea)
+          }.to change(idea.likes, :count).by(-1)
+        end
+      end
+
+      context "いいね！していない場合" do
+        it 'RecordNotFoundが返る' do
+          expect {
+            user.dislike(idea)
+          }.to raise_error(ActiveRecord::RecordNotFound)
+        end
+      end
+    end
+
+    context "コメントに対して" do
+      context "すでにいいね！している場合" do
+        before do
+          user.like(comment)
+        end
+
+        it 'いいね！を取り消すとlikeが減る' do
+          expect {
+            user.dislike(comment)
+          }.to change(comment.likes, :count).by(-1)
+        end
+      end
+
+      context "いいね！していない場合" do
+        it 'RecordNotFoundが返る' do
+          expect {
+            user.dislike(comment)
+          }.to raise_error(ActiveRecord::RecordNotFound)
+        end
+      end
+
+    end
+
+
+  end
 end