Cache question

Gemfile

@@ -54,6 +54,7 @@ gem 'thinking-sphinx'
 gem 'dotenv'
 gem 'dotenv-deployment', require: 'dotenv/deployment'
 gem 'unicorn'
+gem 'redis-rails'
 
 group :doc do
   # bundle exec rake doc:rails generates the API under doc/api.

Gemfile.lock

@@ -310,6 +310,22 @@ GEM
     rdoc (4.2.2)
       json (~> 1.4)
     redis (3.3.0)
+    redis-actionpack (5.0.0)
+      actionpack (>= 4.0.0, < 6)
+      redis-rack (~> 2.0.0.pre)
+      redis-store (~> 1.2.0.pre)
+    redis-activesupport (5.0.1)
+      activesupport (>= 3, < 6)
+      redis-store (~> 1.2.0)
+    redis-rack (2.0.0.pre)
+      rack (> 1.5, < 3)
+      redis-store (~> 1.2.0.pre)
+    redis-rails (5.0.1)
+      redis-actionpack (~> 5.0.0)
+      redis-activesupport (~> 5.0.0)
+      redis-store (~> 1.2.0)
+    redis-store (1.2.0)
+      redis (>= 2.2)
     remotipart (1.2.1)
     responders (2.2.0)
       railties (>= 4.2.0, < 5.1)
@@ -465,6 +481,7 @@ DEPENDENCIES
   pg
   private_pub
   rails (= 4.2)
+  redis-rails
   remotipart
   responders
   rspec-rails

app/helpers/application_helper.rb

@@ -1,2 +1,8 @@
 module ApplicationHelper
+  def collection_cache_key_for(model)
+    klass = model.to_s.capitalize.constantize
+    count = klass.count
+    max_updated_at = klass.maximum(:updated_at).try(:utc).try(:to_s, :number)
+    "#{model.to_s.pluralize}/collection-#{count}-#{max_updated_at}"
+  end
 end

app/models/answer.rb

@@ -2,7 +2,7 @@ class Answer < ActiveRecord::Base
   include Voteable
   default_scope { order('accepted DESC') }
 
-  belongs_to :question
+  belongs_to :question, touch: true
   belongs_to :user
   has_many :attachments, as: :attachmentable
   has_many :comments, as: :commentable

app/models/comment.rb

@@ -1,5 +1,5 @@
 class Comment < ActiveRecord::Base
   belongs_to :user
-  belongs_to :commentable, polymorphic: true
+  belongs_to :commentable, polymorphic: true, touch: true
   validates :body, presence: true
 end

app/views/answers/_answer.html.slim

@@ -5,27 +5,27 @@ div { data-answer = answer.id }
     span = 'Accepted'
 
   - if answer.persisted?
+    - cache answer do
+      = render 'questions/vote', voteable: answer
+      = render 'questions/comments', commentable: answer
 
-    = render 'questions/vote', voteable: answer
-    = render 'questions/comments', commentable: answer
+      ul.answer-attachments
+        - answer.attachments.each do |a|
+          li { data-id = a.id }
+            = link_to a.file.filename, a.file.url
+            = ' '
+            - if current_user && current_user.author_of?(answer)
+              = link_to 'Remove attachment', destroy_attachment_path(a), method: 'delete', remote: true
 
-    ul.answer-attachments
-      - answer.attachments.each do |a|
-        li { data-id = a.id }
-          = link_to a.file.filename, a.file.url
-          = ' '
-          - if current_user && current_user.author_of?(answer)
-            = link_to 'Remove attachment', destroy_attachment_path(a), method: 'delete', remote: true
+      - if current_user
+        - if current_user.author_of?(answer)
+          p = link_to 'Remove answer', question_answer_path(@question, answer), method: 'delete', remote: true
+          p = link_to 'Edit answer', '', class: 'edit-answer-link', data: { answer_id: answer.id }
 
-    - if current_user
-      - if current_user.author_of?(answer)
-        p = link_to 'Remove answer', question_answer_path(@question, answer), method: 'delete', remote: true
-        p = link_to 'Edit answer', '', class: 'edit-answer-link', data: { answer_id: answer.id }
+        - if current_user.author_of?(@question)
+          p = link_to 'Accept answer', accept_question_answer_path(@question, answer), class: 'accept-answer-link', method: 'post', remote: true
 
-      - if current_user.author_of?(@question)
-        p = link_to 'Accept answer', accept_question_answer_path(@question, answer), class: 'accept-answer-link', method: 'post', remote: true
-
-      = form_for [@question, answer], remote: true, html: {id: "edit-answer-#{answer.id}"} do |f|
-        = f.label :body, 'Answer'
-        = f.text_area :body
-        = f.submit 'Save'
+        = form_for [@question, answer], remote: true, html: {id: "edit-answer-#{answer.id}"} do |f|
+          = f.label :body, 'Answer'
+          = f.text_area :body
+          = f.submit 'Save'

app/views/questions/_comments.html.slim

@@ -1,6 +1,7 @@
 .comments
   - commentable.comments.each do |comment|
-    p= comment.body
+    - cache comment do
+      p= comment.body
 
 .comments-form
   = form_for [commentable, commentable.comments.build], remote: true do |f|

app/views/questions/index.html.slim

@@ -4,9 +4,10 @@
   p = 'Is no questions'
 - else
   table.questions
-    - @questions.each do |question|
-      tr
-        td= link_to question.title, question
-        td= question.body
+    - cache collection_cache_key_for :question do
+      - @questions.each do |question|
+        tr
+          td= link_to question.title, question
+          td= question.body
 
 = subscribe_to "/questions"

app/views/questions/show.html.slim

@@ -1,28 +1,30 @@
-.question
-  = render @question
-  = render 'vote', voteable: @question
-  = render 'comments', commentable: @question
-  - if current_user
-    - if @subscription = current_user.subscriptions.find_by(question_id: @question.id)
-      = link_to 'Cancel subscription', question_subscription_path(@question, @subscription), method: 'delete', remote: true, class: 'cancel_subscribe'
-    - else
-      = link_to 'Create subscription', question_subscriptions_path(@question), method: 'post', remote: true, class: 'create_subscribe'
+- cache @question do
+  .question
+    = render @question
+    = render 'vote', voteable: @question
+    = render 'comments', commentable: @question
+    - if current_user
+      - if @subscription = current_user.subscriptions.find_by(question_id: @question.id)
+        = link_to 'Cancel subscription', question_subscription_path(@question, @subscription), method: 'delete', remote: true, class: 'cancel_subscribe'
+      - else
+        = link_to 'Create subscription', question_subscriptions_path(@question), method: 'post', remote: true, class: 'create_subscribe'
 
-- if current_user && current_user.author_of?(@question)
-  = link_to 'Remove', question_path(@question), method: 'delete'
+  - if current_user && current_user.author_of?(@question)
+    = link_to 'Remove', question_path(@question), method: 'delete'
 
-.answers data={question_id: "#{@question.id}"}
-  = render @question.answers
-= subscribe_to "/questions/#{@question.id}/answers"
-= subscribe_to "/questions/#{@question.id}/comments"
+  .answers data={question_id: "#{@question.id}"}
+    = render @question.answers
+
+  .answer_form
+    = form_for [@question, @answer], remote: true do |f|
+      = f.label :body, 'Your Answer'
+      .answer-errors
+      = f.text_area :body
+      ul.files
+        = f.fields_for :attachments, @answer.attachments.build do |a|
+          = render 'attachment_fields', f: a
+        li = link_to_add_association 'Add file', f, :attachments
+      = f.submit 'Post Your Answer'
 
-.answer_form
-  = form_for [@question, @answer], remote: true do |f|
-    = f.label :body, 'Your Answer'
-    .answer-errors
-    = f.text_area :body
-    ul.files
-      = f.fields_for :attachments, @answer.attachments.build do |a|
-        = render 'attachment_fields', f: a
-      li = link_to_add_association 'Add file', f, :attachments
-    = f.submit 'Post Your Answer'
+= subscribe_to "/questions/#{@question.id}/answers"
+= subscribe_to "/questions/#{@question.id}/comments"

config/application.rb

@@ -32,6 +32,7 @@ class Application < Rails::Application
                         request_specs: false,
                         controller_specs: true
       g.fixture_replacement :factory_girl, dir: 'spec/factories'
+      config.cache_store = :redis_store, 'redis://localhost:6379/0/cache', { expares_in: 90.minutes }
     end
   end
 end

config/environments/development.rb

@@ -11,7 +11,7 @@
 
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
-  config.action_controller.perform_caching = false
+  config.action_controller.perform_caching = true
 
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false