Implement caching for Question page

Gemfile

@@ -36,6 +36,7 @@ gem 'sinatra', require: false
 gem 'whenever'
 gem 'dotenv'
 gem 'dotenv-deployment', require: 'dotenv/deployment'
+gem 'redis-rails'
 
 gem 'mysql2' # Don't worry, it's for Sphinx only!
 gem 'thinking-sphinx'

Gemfile.lock

@@ -342,6 +342,22 @@ GEM
     rdoc (4.2.2)
       json (~> 1.4)
     redis (3.3.1)
+    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 (1.3.0)
     request_store (1.3.1)
     require_all (1.3.3)
@@ -524,6 +540,7 @@ DEPENDENCIES
   rails (= 4.2.6)
   rails_best_practices
   rb-fsevent
+  redis-rails
   remotipart
   responders
   rspec-rails (~> 3.0)

app/controllers/concerns/rated.rb

@@ -2,7 +2,6 @@ module Rated
   extend ActiveSupport::Concern
   included do
     before_action :find_rateable, only: [:rate_inc, :rate_dec, :rate_revoke]
-    before_action :protect_forbidden_rate, only: [:rate_inc, :rate_dec]
   end
 
   def rate_inc
@@ -18,8 +17,8 @@ def rate_dec
   end
 
   def rate_revoke
-    authorize @rateable, :rate_revoke?
-    return head :forbidden unless current_user? || rate_exists?
+    authorize @rateable, :rate?
+    return head :forbidden unless current_user? || own_rate_exists?
     @rateable.revoke_rate!(current_user)
     render json: json_data(true)
   end
@@ -34,15 +33,11 @@ def current_user?
     @rateable.user_id == current_user.id
   end
 
-  def rate_exists?
+  def own_rate_exists?
     Rating.exists?(rateable: @rateable, user_id: current_user.id)
   end
 
   def find_rateable
     @rateable = controller_name.classify.constantize.find(params[:id])
   end
-
-  def protect_forbidden_rate
-    head :forbidden if current_user? || rate_exists?
-  end
-end
+end

app/jobs/mail_digest_job.rb

@@ -2,7 +2,7 @@ class MailDigestJob < ActiveJob::Base
   queue_as :mailers
 
   def perform
-    question_ids = Question.where(created_at: Time.now.yesterday.all_day).order(created_at: :desc).map(&:id)
+    question_ids = Question.where(created_at: Time.now.yesterday.all_day).order(:created_at).map(&:id)
 
     User.find_each do |user|
       CustomMailer.digest(user, question_ids).deliver_later

app/models/answer.rb

@@ -3,7 +3,7 @@ class Answer < ActiveRecord::Base
   include Commentable
 
   belongs_to :user
-  belongs_to :question
+  belongs_to :question, touch: true
   has_many :attachments, as: :attachable, dependent: :destroy
 
   accepts_nested_attributes_for :attachments, reject_if: :all_blank

app/models/attachment.rb

@@ -1,5 +1,5 @@
 class Attachment < ActiveRecord::Base
-  belongs_to :attachable, polymorphic: true
+  belongs_to :attachable, polymorphic: true, touch: true
 
   mount_uploader :file, FileUploader
 

app/models/comment.rb

@@ -1,6 +1,6 @@
 class Comment < ActiveRecord::Base
   belongs_to :user
-  belongs_to :commentable, polymorphic: true
+  belongs_to :commentable, polymorphic: true, touch: true
 
   validates :user_id, presence: true
   validates :body, presence: true, length: (2..2_000)

app/models/subscription.rb

@@ -1,6 +1,6 @@
 class Subscription < ActiveRecord::Base
   belongs_to :user
-  belongs_to :question
+  belongs_to :question, touch: true
 
   validates :question_id, :user_id, presence: true
 

app/policies/rateable_policy.rb

@@ -2,8 +2,4 @@ module RateablePolicy
   def rate?
     admin? || user? && !owner?
   end
-
-  def rate_revoke?
-    admin? || owner?
-  end
-end
+end

app/views/comments/_comment.slim

@@ -1,9 +1,10 @@
-p id="comment-#{comment.id}"
-  = comment.body
-  span.little style="color:gray"
-    '
-    ' —
-    => comment.user.email
-    ' at
-    = l comment.created_at, format: :short
-hr style="margin:0 0 8px 0"
+- cache [:comment_form, comment] do
+  p id="comment-#{comment.id}"
+    = comment.body
+    span.little style="color:gray"
+      '
+      ' —
+      => comment.user.email
+      ' at
+      = l comment.created_at, format: :short
+  hr style="margin:0 0 8px 0"

app/views/comments/_list.slim

@@ -1,10 +1,11 @@
 .comments id="#{commentable.entity}-comments-#{commentable.id}-container"
-  div id="#{commentable.entity}-comments-#{commentable.id}-header" style="#{commentable.comments.any? ? '' : 'display:none'}"
-    hr style="margin:2px 4px 0 4px"
-    h4 Comments:
-  div id="#{commentable.entity}-comments-#{commentable.id}" style="margin-left:40px"
-    - commentable.comments.each do |comment|
-      = render 'comments/comment', comment: comment
+  - cache [commentable, :comment_list] do
+    div id="#{commentable.entity}-comments-#{commentable.id}-header" style="#{commentable.comments.any? ? '' : 'display:none'}"
+      hr style="margin:2px 4px 0 4px"
+      h4 Comments:
+    div id="#{commentable.entity}-comments-#{commentable.id}" style="margin-left:40px"
+      - commentable.comments.each do |comment|
+        = render 'comments/comment', comment: comment
 
   - if policy(Comment).create?
     div id="#{commentable.entity}-comments-#{commentable.id}-errors"

app/views/questions/_answer.slim

@@ -1,35 +1,36 @@
-div id="answer-#{answer.id}" class="#{answer.starred ? 'answer-starred' : ''}"
-  .row
-    .col-xs-12
-      - if answer.starred
-        p.best-answer
-          strong Best Answer:
-      .pull-right id="answer-buttons-#{answer.id}"
-      - if comet
-        javascript:
-          $("#answer-buttons-#{answer.id}").html(JST["answer_buttons"]({
-            question_id: "#{answer.question.id}",
-            question_user_id: "#{answer.question.user.id}",
-            answer_id: "#{answer.id}",
-            answer_user_id: "#{answer.user.id}"
-          }));
-      - else
-        - if policy(answer).destroy?
-          => link_to 'Delete', answer_path(answer), id: "delete-answer-#{answer.id}", class: "btn btn-danger btn-sm", method: :delete, remote: true
-        - if policy(answer).edit?
-          => link_to 'Edit', '#', id: "edit-answer-link-#{answer.id}", class: "btn btn-info btn-sm edit-answer-link", data: {answer_id: answer.id}
-        - if policy(answer).star?
-          = link_to 'Star', star_answer_path(answer), id: "star-answer-link-#{answer.id}", class: "btn btn-warning btn-sm star-answer-link", data: {answer_id: answer.id}, method: :patch, remote: true
-      = render 'shared/rating', rateable: answer
-      blockquote
-        = answer.body
-        = render 'questions/attachments', attachable: answer
-        = render 'comments/list', commentable: answer, comet: false
-        - if policy(answer).update?
-          div
-            = form_for answer, remote: true do |f|
-              = f.label :body, 'Answer'
-              .little id="answer-errors-#{answer.id}"
-              = f.text_area :body, class: 'form-control'
-              = f.submit 'Save', class: "btn btn-info btn-sm pull-right"
-      hr
+- cache [answer, policy(answer).edit?, policy(answer).destroy?, policy(answer).star?, comet]
+  div id="answer-#{answer.id}" class="#{answer.starred ? 'answer-starred' : ''}"
+    .row
+      .col-xs-12
+        - if answer.starred
+          p.best-answer
+            strong Best Answer:
+        .pull-right id="answer-buttons-#{answer.id}"
+        - if comet
+          javascript:
+            $("#answer-buttons-#{answer.id}").html(JST["answer_buttons"]({
+              question_id: "#{answer.question.id}",
+              question_user_id: "#{answer.question.user.id}",
+              answer_id: "#{answer.id}",
+              answer_user_id: "#{answer.user.id}"
+            }));
+        - else
+          - if policy(answer).destroy?
+            => link_to 'Delete', answer_path(answer), id: "delete-answer-#{answer.id}", class: 'btn btn-danger btn-sm', method: :delete, remote: true
+          - if policy(answer).edit?
+            => link_to 'Edit', '#', id: "edit-answer-link-#{answer.id}", class: 'btn btn-info btn-sm edit-answer-link', data: {answer_id: answer.id}
+          - if policy(answer).star?
+            = link_to 'Star', star_answer_path(answer), id: "star-answer-link-#{answer.id}", class: 'btn btn-warning btn-sm star-answer-link', data: {answer_id: answer.id}, method: :patch, remote: true
+        = render 'shared/rating', rateable: answer
+        blockquote
+          = answer.body
+          = render 'questions/attachments', attachable: answer
+          = render 'comments/list', commentable: answer, comet: false
+          - if policy(answer).edit?
+            div
+              = form_for answer, remote: true do |f|
+                = f.label :body, 'Answer'
+                .little id="answer-errors-#{answer.id}"
+                = f.text_area :body, class: 'form-control'
+                = f.submit 'Save', class: 'btn btn-info btn-sm pull-right'
+        hr

app/views/questions/_attachments.slim

@@ -2,8 +2,9 @@
   hr
   p
     | Attachments:
-    - attachable.attachments.each do |a|
-      div id="attachment-#{a.id}"
-        => glyph :paperclip
-        => link_to a.file.filename, a.file.url
-        = link_to '×'.html_safe, attachment_path(a), remote: true, method: :delete, id: "delete-attachment-#{a.id}", style: 'font-size:1.3em;font-weight:bold;color:red'
+    - attachable.attachments.each do |attachment|
+      - cache attachment do
+        div id="attachment-#{attachment.id}"
+          => glyph :paperclip
+          => link_to attachment.file.filename, attachment.file.url
+          = link_to '×'.html_safe, attachment_path(attachment), remote: true, method: :delete, id: "delete-attachment-#{attachment.id}", style: 'font-size:1.3em;font-weight:bold;color:red'

app/views/questions/_question.slim

@@ -1,30 +1,32 @@
-div id="question-#{question.id}"
-  row
-    .col-sm-10
-      p.lead
-        = link_to question_path(question)
-          = question.topic
-        - if policy(question).update?
-        div
-          = form_for question, remote: true do |f|
-            .little id="question-errors-#{question.id}"
-            = f.label :topic, 'Topic'
-            = f.text_field :topic, class: 'form-control'
-            = f.label :body, 'Question'
-            = f.text_area :body, class: 'form-control'
-            = f.submit 'Save', class: "btn btn-info btn-sm pull-right"
-    .col-sm-2
-      .pull-right id="question-buttons-#{question.id}"
-      - if comet
-        javascript:
-          $("#question-buttons-#{question.id}").html(JST["question_buttons"]({
-            question_id: "#{question.id}",
-            question_user_id: "#{question.user.id}"
-          }));
-      - else
-        - if policy(question).edit?
-          = link_to 'Edit', '#', id: "edit-question-link-#{question.id}", class: "btn btn-info btn-sm edit-question-link pull-right", data: {question_id: question.id}
-      = render 'shared/rating', rateable: question
-  row
-    .col-xs-12
-      hr
+- cache [question, policy(question).update?, comet]
+  div id="question-#{question.id}"
+    .row
+      .col-sm-10
+        p.lead
+          = link_to question_path(question)
+            = question.topic
+          - if policy(question).update?
+          div
+            = form_for question, remote: true do |f|
+              .little id="question-errors-#{question.id}"
+              = f.label :topic, 'Topic'
+              = f.text_field :topic, class: 'form-control'
+              = f.label :body, 'Question'
+              = f.text_area :body, class: 'form-control'
+              = f.submit 'Save', class: "btn btn-info btn-sm pull-right"
+      .col-sm-2
+        .pull-right id="question-buttons-#{question.id}"
+        - if comet
+          javascript:
+            $("#question-buttons-#{question.id}").html(JST["question_buttons"]({
+              question_id: "#{question.id}",
+              question_user_id: "#{question.user.id}"
+            }));
+        - else
+          - if policy(question).edit?
+            = link_to 'Edit', '#', id: "edit-question-link-#{question.id}", \
+              class: 'btn btn-info btn-sm edit-question-link pull-right', data: {question_id: question.id}
+        = render 'shared/rating', rateable: question
+    .row
+      .col-xs-12
+        hr