Add caching

Gemfile

@@ -71,6 +71,8 @@ gem "mini_racer", "~> 0.6.2"
 
 gem "unicorn", "~> 6.1"
 
+gem "redis-rails", "~> 5.0", ">= 5.0.2"
+
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem "byebug", platforms: [:mri, :mingw, :x64_mingw]

Gemfile.lock

@@ -330,6 +330,22 @@ GEM
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     redis (4.6.0)
+    redis-actionpack (5.3.0)
+      actionpack (>= 5, < 8)
+      redis-rack (>= 2.1.0, < 3)
+      redis-store (>= 1.1.0, < 2)
+    redis-activesupport (5.3.0)
+      activesupport (>= 3, < 8)
+      redis-store (>= 1.3, < 2)
+    redis-rack (2.1.4)
+      rack (>= 2.0.8, < 3)
+      redis-store (>= 1.2, < 2)
+    redis-rails (5.0.2)
+      redis-actionpack (>= 5.0, < 6)
+      redis-activesupport (>= 5.0, < 6)
+      redis-store (>= 1.2, < 2)
+    redis-store (1.9.1)
+      redis (>= 4, < 5)
     regexp_parser (2.1.1)
     representable (3.1.1)
       declarative (< 0.1.0)
@@ -497,6 +513,7 @@ DEPENDENCIES
   rack-mini-profiler (~> 2.0)
   rails (~> 6.1.3)
   rails-controller-testing (~> 1.0, >= 1.0.5)
+  redis-rails (~> 5.0, >= 5.0.2)
   rspec-rails (~> 5.0, >= 5.0.2)
   sass-rails (>= 6)
   selenium-webdriver

app/helpers/application_helper.rb

@@ -1,2 +1,8 @@
 module ApplicationHelper
+  def collection_cache_helper_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 < ApplicationRecord
   include Votable
   include Commentable
 
-  belongs_to :question
+  belongs_to :question, touch: true
   belongs_to :author, class_name: "User"
   has_many :links, dependent: :destroy, as: :linkable
 

app/models/comment.rb

@@ -1,6 +1,6 @@
 class Comment < ApplicationRecord
   belongs_to :user
-  belongs_to :commentable, polymorphic: true
+  belongs_to :commentable, polymorphic: true, touch: true
 
   validates :body, presence: true
 end

app/models/link.rb

@@ -1,5 +1,5 @@
 class Link < ApplicationRecord
-  belongs_to :linkable, polymorphic: true
+  belongs_to :linkable, polymorphic: true, touch: true
 
   validates :name, :url, presence: true
   validates :url, format: URI::regexp(%w[http https])

app/models/subscription.rb

@@ -1,6 +1,6 @@
 class Subscription < ApplicationRecord
   belongs_to :user
-  belongs_to :question
+  belongs_to :question, touch: true
 
   validates :user, uniqueness: { scope: :question_id }
 end

app/models/vote.rb

@@ -1,6 +1,6 @@
 class Vote < ApplicationRecord
   belongs_to :user
-  belongs_to :votable, polymorphic: true
+  belongs_to :votable, polymorphic: true, touch: true
 
   validates :status, presence: true
   validates :user, uniqueness: { scope: %i[votable_type votable_id] }

app/views/answers/_answer.html.slim

@@ -1,33 +1,34 @@
-li id="answer-li-#{answer.id}"
-  p = answer.body
-  - if (can? :destroy, answer) && (can? :update, answer)
-    p = link_to 'Delete answer', answer_path(answer), method: :delete, data: { confirm: "Are you sure?" }, remote: true
-    p = link_to "Edit", "#", class: "edit-answer-link", data: { answer_id: answer.id }
-    = form_with model: answer, local: false, class: 'hidden', html: {id: "edit-answer-#{answer.id}"} do |f|
-      = f.label :body
-      = f.text_area :body
-      p
-        = f.label :files
-        = f.file_field :files, multiple: true
-      p Links: 
-      p 
-        = f.fields_for :links do |link|
-          = render 'link_fields', f: link
-        .links
-          = link_to_add_association 'Add link', f, :links
-      = f.submit 'Save'
-  - if can?(:mark_as_best, @question)
-    p = link_to 'Mark answer as best', mark_answer_as_best_question_path(@question, answer_id: answer.id), method: :patch
-  = render 'shared/attached_files', resource: answer
-  .answer-links
-    = render 'shared/attached_links', resource: answer
-  .answer-vote 
-    = render 'shared/vote', resource: answer
-  div id="answer-#{answer.id}-comments"
-    - if answer.comments.first
-      h4 = "Comments:"
-    ul 
-      = render answer.comments
-    - if user_signed_in?     
-        p = link_to 'Add comment', "#", class: "add-comment", data: { answer_id: answer.id }
-        = render 'comments/form', commentable: answer
+- cache answer do
+  li id="answer-li-#{answer.id}"
+    p = answer.body
+    - if (can? :destroy, answer) && (can? :update, answer)
+      p = link_to 'Delete answer', answer_path(answer), method: :delete, data: { confirm: "Are you sure?" }, remote: true
+      p = link_to "Edit", "#", class: "edit-answer-link", data: { answer_id: answer.id }
+      = form_with model: answer, local: false, class: 'hidden', html: {id: "edit-answer-#{answer.id}"} do |f|
+        = f.label :body
+        = f.text_area :body
+        p
+          = f.label :files
+          = f.file_field :files, multiple: true
+        p Links: 
+        p 
+          = f.fields_for :links do |link|
+            = render 'link_fields', f: link
+          .links
+            = link_to_add_association 'Add link', f, :links
+        = f.submit 'Save'
+    - if can?(:mark_as_best, @question)
+      p = link_to 'Mark answer as best', mark_answer_as_best_question_path(@question, answer_id: answer.id), method: :patch
+    = render 'shared/attached_files', resource: answer
+    .answer-links
+      = render 'shared/attached_links', resource: answer
+    .answer-vote 
+      = render 'shared/vote', resource: answer
+    div id="answer-#{answer.id}-comments"
+      - if answer.comments.first
+        h4 = "Comments:"
+      ul 
+        = render answer.comments
+      - if user_signed_in?     
+          p = link_to 'Add comment', "#", class: "add-comment", data: { answer_id: answer.id }
+          = render 'comments/form', commentable: answer

app/views/comments/_comment.html.slim

@@ -1,3 +1,4 @@
-li id="comment-#{comment.id}"
-  p = comment.body 
-  p = "Author: #{comment.user.email}"
+- cache comment do
+  li id="comment-#{comment.id}"
+    p = comment.body 
+    p = "Author: #{comment.user.email}"

app/views/questions/index.html.slim

@@ -2,15 +2,16 @@ p= link_to 'Ask question', new_question_path
 
 h2 Questions list
 
-table class="questions-index-table"
-  tr
-    th
-      p Question title
-    th
-      p Question Body
-    th 
-      p View question
-  = render @questions
+-cache collection_cache_helper_for :question do
+  table class="questions-index-table"
+    tr
+      th
+        p Question title
+      th
+        p Question Body
+      th 
+        p View question
+    = render @questions
 
 - if current_user
   p = link_to 'View Awards', awards_path

app/views/questions/show.html.slim

@@ -1,80 +1,81 @@
-.question
-  .question-errors
-  h1 Question title
-  h3 id="question-title-#{@question.id}" = @question.title
-  - if can?(:update, @question)
-    p = link_to 'Edit title', "#", class: "edit-question-title-link", data: { question_id: @question.id }
-    = form_with model: @question, local: false, class: 'hidden', html: {id: "edit-question-title-#{@question.id}"} do |f|
-      = f.label :title
-      = f.text_area :title
-      = f.submit 'Save'
+- cache @question do
+  .question
+    .question-errors
+    h1 Question title
+    h3 id="question-title-#{@question.id}" = @question.title
+    - if can?(:update, @question)
+      p = link_to 'Edit title', "#", class: "edit-question-title-link", data: { question_id: @question.id }
+      = form_with model: @question, local: false, class: 'hidden', html: {id: "edit-question-title-#{@question.id}"} do |f|
+        = f.label :title
+        = f.text_area :title
+        = f.submit 'Save'
 
-  h1 Question body
-  h3 id="question-body-#{@question.id}" = @question.body
-  - if can?(:update, @question)
-    p = link_to 'Edit body', "#", class: "edit-question-body-link", data: { question_id: @question.id }
-    = form_with model: @question, local: false, class: 'hidden', html: {id: "edit-question-body-#{@question.id}"} do |f|
-      = f.label :body
-      = f.text_area :body
-      p
-        = f.label :files
-        = f.file_field :files, multiple: true
-      p Links: 
-      p 
-        = f.fields_for :links do |link|
-          = render 'link_fields', f: link
-        .links
-          = link_to_add_association 'Add link', f, :links
-      = f.submit 'Save'
+    h1 Question body
+    h3 id="question-body-#{@question.id}" = @question.body
+    - if can?(:update, @question)
+      p = link_to 'Edit body', "#", class: "edit-question-body-link", data: { question_id: @question.id }
+      = form_with model: @question, local: false, class: 'hidden', html: {id: "edit-question-body-#{@question.id}"} do |f|
+        = f.label :body
+        = f.text_area :body
+        p
+          = f.label :files
+          = f.file_field :files, multiple: true
+        p Links: 
+        p 
+          = f.fields_for :links do |link|
+            = render 'link_fields', f: link
+          .links
+            = link_to_add_association 'Add link', f, :links
+        = f.submit 'Save'
 
-  .question-files-list
-    = render 'shared/attached_files', resource: @question
+    .question-files-list
+      = render 'shared/attached_files', resource: @question
 
-  .question-links
-    = render 'shared/attached_links', resource: @question
-  .question-award
-    = render 'shared/attached_award', resource: @question.award
-  .question-vote
-    = render 'shared/vote', resource: @question
-  div id="question-#{@question.id}-comments"
-    - if @question.comments.first
-        h4 = "Comments:"
-    ul
-      = render @question.comments
-    - if user_signed_in?     
-        p = link_to 'Add comment', "#", class: "add-comment", data: { question_id: @question.id }
-        = render 'comments/form', commentable: @question 
-  .question-subscribed 
-    - if user_signed_in?
-      = render 'shared/subscription', resource: @question
+    .question-links
+      = render 'shared/attached_links', resource: @question
+    .question-award
+      = render 'shared/attached_award', resource: @question.award
+    .question-vote
+      = render 'shared/vote', resource: @question
+    div id="question-#{@question.id}-comments"
+      - if @question.comments.first
+          h4 = "Comments:"
+      ul
+        = render @question.comments
+      - if user_signed_in?     
+          p = link_to 'Add comment', "#", class: "add-comment", data: { question_id: @question.id }
+          = render 'comments/form', commentable: @question 
+    .question-subscribed 
+      - if user_signed_in?
+        = render 'shared/subscription', resource: @question
 
-h2 = "Answers list"
-.answer-errors
-.answers
-  ol
-    - if @best_answer.present?
-      .best-answer
-        = render @best_answer
-    = render @other_answers
+  h2 = "Answers list"
+  .answer-errors
+  .answers
+    ol
+      - if @best_answer.present?
+        .best-answer
+          = render @best_answer
+      = render @other_answers
 
-- if current_user
-    h2 Create new answer
-    .answer-errors-create
-    = form_with model: [@question, @answer], local: false do |f|
-      = f.label :body
-      = f.text_area :body
-      p
-        = f.label :files
-        = f.file_field :files, multiple: true
-      p Links: 
-      p 
-        = f.fields_for :links do |link|
-          = render 'link_fields', f: link
-        .links
-          = link_to_add_association 'Add link', f, :links
-      = f.submit 'Create'
+  - if current_user
+      h2 Create new answer
+      .answer-errors-create
+      = form_with model: [@question, @answer], local: false do |f|
+        = f.label :body
+        = f.text_area :body
+        p
+          = f.label :files
+          = f.file_field :files, multiple: true
+        p Links: 
+        p 
+          = f.fields_for :links do |link|
+            = render 'link_fields', f: link
+          .links
+            = link_to_add_association 'Add link', f, :links
+        = f.submit 'Create'
 
-p = link_to 'Back to questions list', questions_path
+  p = link_to 'Back to questions list', questions_path
 
-- if can?(:destroy, @question)
-  p = link_to 'Delete', question_path(@question), method: :delete, data: { confirm: "Are you sure?" }
+  - if can?(:destroy, @question)
+    p = link_to 'Delete', question_path(@question), method: :delete, data: { confirm: "Are you sure?" }

app/views/shared/_attached_links.html.slim

@@ -1,10 +1,11 @@
-- if resource.links.first
-  h4 = "Links attached:"
-  ul
-    - resource.links.each do |link|
-        - if link.gist?
-            li = javascript_include_tag link.url+".js"
-        - else 
-            li = link_to link.name, link.url
-        = link_to 'Remove', link_path(link.id), method: :delete, data: { confirm: 'Are you sure?' } if current_user&.author_of?(link.linkable)
+-cache resource do
+  - if resource.links.first
+    h4 = "Links attached:"
+    ul
+      - resource.links.each do |link|
+          - if link.gist?
+              li = javascript_include_tag link.url+".js"
+          - else 
+              li = link_to link.name, link.url
+          = link_to 'Remove', link_path(link.id), method: :delete, data: { confirm: 'Are you sure?' } if current_user&.author_of?(link.linkable)
 

config/application.rb

@@ -24,6 +24,8 @@ class Application < Rails::Application
     config.active_job.queue_adapter = :sidekiq
     config.autoload_paths += [config.root.join("app")]
 
+    config.cache_store = :redis_store, "redis://localhost:6379/0/cache", { expires_in: 90.minutes }
+
     config.generators do |g|
       g.test_framework :rspec,
                        view_specs: false,

config/environments/development.rb

@@ -25,9 +25,11 @@
       "Cache-Control" => "public, max-age=#{2.days.to_i}",
     }
   else
-    config.action_controller.perform_caching = false
+    config.action_controller.perform_caching = true
 
     config.cache_store = :null_store
+
+    config.action_controller.enable_fragment_cache_logging = true
   end
 
   # Store uploaded files on the local file system (see config/storage.yml for options).