Agile Web Development with Rails, Edition 4

22 Caching

Restart the server.

curl --silent --dump - --output /dev/null http://localhost:3000/

HTTP/1.1 200 OK

X-Frame-Options: SAMEORIGIN

X-Xss-Protection: 1; mode=block

X-Content-Type-Options: nosniff

X-Xhr-Current-Location: /

Content-Type: text/html; charset=utf-8

X-Ua-Compatible: IE=Edge

Etag: "5bb3f6b40f80c80451f647aa7ed3d133"

Cache-Control: max-age=0, private, must-revalidate

X-Request-Id: a38f0caf-5c72-42d9-9bfc-c5863a2020c1

X-Runtime: 0.331800

Content-Length: 6205

Server: WEBrick/1.3.1 (Ruby/2.0.0/2012-12-10)

Date: Mon, 10 Dec 2012 01:00:53 GMT

Connection: Keep-Alive

Set-Cookie: _depot_session=blVaOHZ4RWpRaDNYbzg1Mkl3UVFEWEhoOVhwT3d5THdlWFNXL1NNTFYwbVI2d3VMZkgyTXNYRjRTSnZLVkVFa0huTk5uYW9YRGNad1ZzaG1ZRnVJdzNTa3c3ck1LQnFKeUJYZmg1VW1sYldDTU9OM3V6N29idERqcElCTXJIWkpiUmNRRjR3RUFieVBrS0NUcTF1TE5GbnowUGZESHgrbFI4S0hZUGZLN0RnNWRqajFuOTF0Z3FYSGJHTUx6R0t3eUYzZlhHc1pKZGJsbWR5UlJXSWVydz09LS1EWEZsMldvZGVLb080US9lNStjWStnPT0%3D--3acbc565a26311e06faa20edb38b2cfe4c0c50c0; path=/; HttpOnly

add a method to return the latest product

edit app/models/product.rb

  def self.latest

    Product.order('updated_at desc').limit(1).first

end

set ETAG and LastModified headers on the response

edit app/controllers/store_controller.rb

class StoreController < ApplicationController

  skip_before_filter :authorize

  def index

    if params[:set_locale]

      redirect_to store_path(locale: params[:set_locale])

    else

      @products = Product.order(:title)

      @cart = current_cart

end

    latest = Product.latest

    fresh_when etag: latest, last_modified: latest.created_at.utc

    expires_in 10.minutes, public: true

end

end

curl --silent --dump - --output /dev/null http://localhost:3000/

HTTP/1.1 200 OK

X-Frame-Options: SAMEORIGIN

X-Xss-Protection: 1; mode=block

X-Content-Type-Options: nosniff

X-Xhr-Current-Location: /

Etag: "1c3e833cf0a378d3337f01528bb0a240"

Last-Modified: Mon, 10 Dec 2012 00:51:47 GMT

Date: Mon, 10 Dec 2012 01:00:53 GMT

Content-Type: text/html; charset=utf-8

Cache-Control: max-age=600, public

X-Ua-Compatible: IE=Edge

X-Request-Id: edbb246d-2673-4b05-8285-a47e1d6389a2

X-Runtime: 0.549744

Content-Length: 6205

Server: WEBrick/1.3.1 (Ruby/2.0.0/2012-12-10)

Connection: Keep-Alive

Set-Cookie: _depot_session=WDE5N2dmRTFpV2UwbnY0d004MDJ3NlhGTnN0UEpLbVZSMEZBczRleElJOVNPL2tOU05SbzZqQzV4QTBLT0Q1am5NeHAyRXp6NjFWSGl3YkE4VXBXdy9CY2p6UGlMWGlDWDhJbGZiVjRlbTV5M2hjMVJXQ3QxNFRheFRkU1RDMzBpY2hoRVBkQzMwM3F2czV4TDhkVk85Sjg1dE1nRGFINU83WHZZQTNmRnlqT0ZhU0lDTC9iYWNJbHowZVE4WERDUjJJRko2cWoyZkVQaS9Ic2FlN2pDQT09LS1uWmxBTTdKdXRaTnU1Tzk5QUJrOUh3PT0%3D--dc12f83652c0c4cdc13d93bbe04cdbb4df29cdf8; path=/; HttpOnly

curl --silent --dump - --output /dev/null http://localhost:3000/ -H 'If-None-Match: "1c3e833cf0a378d3337f01528bb0a240"'

HTTP/1.1 304 Not Modified

X-Frame-Options: SAMEORIGIN

X-Xss-Protection: 1; mode=block

X-Content-Type-Options: nosniff

X-Xhr-Current-Location: /

Etag: "1c3e833cf0a378d3337f01528bb0a240"

Last-Modified: Mon, 10 Dec 2012 00:51:47 GMT

Date: Mon, 10 Dec 2012 01:00:54 GMT

Cache-Control: max-age=600, public

X-Ua-Compatible: IE=Edge

X-Request-Id: 71c2c554-d6f3-4c76-912d-323b890ff1e0

X-Runtime: 0.147894

Server: WEBrick/1.3.1 (Ruby/2.0.0/2012-12-10)

Connection: Keep-Alive

Set-Cookie: _depot_session=V3hlSGt4dmtuRHFGVHV2VUVBdml6TFVqTUlDdlIwUDZpbkZaU09kOFR6Vm5oblU1cFEydkdXVkVWNGxIbGdQUi9DRTVJaWxJMU1JT3gxMit4SGJ0d2FzeGhuMXBGVWJoZ0wyYUVFd1ZTL2s9LS1XbStLR1RQcjErSEV4TWdVenhMbi9RPT0%3D--854c64005c9fb61e461a6eb853f0ca99db116758; path=/; HttpOnly

curl --silent --dump - --output /dev/null http://localhost:3000/ -H 'If-Modified-Since: Mon, 10 Dec 2012 00:51:47 GMT'

HTTP/1.1 304 Not Modified

X-Frame-Options: SAMEORIGIN

X-Xss-Protection: 1; mode=block

X-Content-Type-Options: nosniff

X-Xhr-Current-Location: /

Etag: "1c3e833cf0a378d3337f01528bb0a240"

Last-Modified: Mon, 10 Dec 2012 00:51:47 GMT

Date: Mon, 10 Dec 2012 01:00:54 GMT

Cache-Control: max-age=600, public

X-Ua-Compatible: IE=Edge

X-Request-Id: 42ab7c5f-f6d8-43da-be76-0a4e3be65eb4

X-Runtime: 0.114905

Server: WEBrick/1.3.1 (Ruby/2.0.0/2012-12-10)

Connection: Keep-Alive

Set-Cookie: _depot_session=NXBTYTRPcW8rdFpmVEs2cWlPT3RpSlpuYjJCcjlZTjN4VlpUZGp3TkR3K0VnNkhhRHpoZWNFdEZwUFFnc1lEVGhCbFFudnVyekYwc3pwRUd3cFhXUnl0dWV2aXNwV2M3enVuMkQ4ZnViaEE9LS1DZFBGM2ZJUUQ0NmRZc2dqTEpIZk5nPT0%3D--85343fd2b49ba0d31a399bf24f3ea3c34b50237a; path=/; HttpOnly

Turn on caching in development

edit config/environments/development.rb

Depot::Application.configure do

  # Settings specified here will take precedence over those in config/application.rb.

  # In the development environment your application's code is reloaded on

  # every request. This slows down response time but is perfect for development

  # since you don't have to restart the web server when you make code changes.

  config.cache_classes = false

  # Do not eager load code on boot.

  config.eager_load = false

  # Show full error reports and disable caching.

  config.consider_all_requests_local       = true

  config.action_controller.perform_caching = true

  config.action_dispatch.rack_cache = true

  # Don't care if the mailer can't send.

  config.action_mailer.raise_delivery_errors = false

  # Don't actually send emails

  config.action_mailer.delivery_method = :test

  # Alternate configuration example, using gmail:

  #   config.action_mailer.delivery_method = :smtp

  #   config.action_mailer.smtp_settings = {

  #     address:        "smtp.gmail.com",

  #     port:           587,

  #     domain:         "domain.of.sender.net",

  #     authentication: "plain",

  #     user_name:      "dave",

  #     password:       "secret",

  #     enable_starttls_auto: true

  #   }

  # Print deprecation notices to the Rails logger.

  config.active_support.deprecation = :log

  # Only use best-standards-support built into browsers.

  config.action_dispatch.best_standards_support = :builtin

  # Log the query plan for queries taking more than this (works

  # with SQLite, MySQL, and PostgreSQL).

  config.active_record.auto_explain_threshold_in_seconds = 0.5

  # Raise an error on page load if there are pending migrations

  config.active_record.migration_error = :page_load

  # Debug mode disables concatenation and preprocessing of assets.

  config.assets.debug = true

end

add 'rack-cache' to the bundle

edit Gemfile

gem 'rack-cache'

bundle install

Using rake (10.0.2)

Using i18n (0.6.1)

Using minitest (4.3.3)

Using multi_json (1.4.0)

Using tzinfo (0.3.35)

Using activesupport (4.0.0.beta)

Using builder (3.1.4)

Using erubis (2.7.0)

Using journey (2.0.0.20120723141804)

Using rack (1.4.1)

Using rack-test (0.6.2)

Using actionpack (4.0.0.beta)

Using mime-types (1.19)

Using polyglot (0.3.3)

Using treetop (1.4.12)

Using mail (2.5.3)

Using actionmailer (4.0.0.beta)

Using activemodel (4.0.0.beta)

Using activerecord-deprecated_finders (0.0.1)

Using arel (3.0.2.20120819075748)

Using activerecord (4.0.0.beta)

Using activeresource (4.0.0.beta)

Using bcrypt-ruby (3.0.1)

Using bundler (1.2.3)

Using highline (1.6.15)

Using net-ssh (2.6.2)

Using net-scp (1.0.4)

Using net-sftp (2.0.5)

Using net-ssh-gateway (1.1.0)

Using capistrano (2.13.5)

Using coffee-script-source (1.4.0)

Using execjs (1.4.0)

Using coffee-script (2.2.0)

Using json (1.7.5)

Using rdoc (3.12)

Using thor (0.16.0)

Using railties (4.0.0.beta)

Using coffee-rails (4.0.0.beta)

Using hike (1.2.1)

Using jquery-rails (2.1.4)

Using kaminari (0.14.1)

Using mysql2 (0.3.11)

Using rack-cache (1.2)

Using tilt (1.3.3)

Using sprockets (2.8.1)

Using sprockets-rails (2.0.0.rc1)

Using rails (4.0.0.beta)

Using sass (3.2.3)

Using sass-rails (4.0.0.beta)

Using sqlite3 (1.3.6)

Using turbolinks (0.6.1)

Using uglifier (1.3.0)

Updating files in vendor/cache

Could not find activesupport-4.0.0.beta.gem for installation

Restart the server.

rake middleware

use Rack::Cache

use ActionDispatch::Static

use Rack::Lock

use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x000000029cb3a8>

use Rack::Runtime

use Rack::MethodOverride

use ActionDispatch::RequestId

use Rails::Rack::Logger

use ActionDispatch::ShowExceptions

use ActionDispatch::DebugExceptions

use ActionDispatch::RemoteIp

use ActionDispatch::Reloader

use ActionDispatch::Callbacks

use ActiveRecord::Migration::CheckPending

use ActiveRecord::ConnectionAdapters::ConnectionManagement

use ActiveRecord::QueryCache

use ActionDispatch::Cookies

use ActionDispatch::Session::EncryptedCookieStore

use ActionDispatch::Flash

use ActionDispatch::ParamsParser

use Rack::Head

use Rack::ConditionalGet

use Rack::ETag

use ActionDispatch::BestStandardsSupport

run Depot::Application.routes

curl --silent --dump - --output /dev/null http://localhost:3000/

HTTP/1.1 200 OK

X-Frame-Options: SAMEORIGIN

X-Xss-Protection: 1; mode=block

X-Content-Type-Options: nosniff

X-Xhr-Current-Location: /

Etag: "1c3e833cf0a378d3337f01528bb0a240"

Last-Modified: Mon, 10 Dec 2012 00:51:47 GMT

Date: Mon, 10 Dec 2012 01:01:06 GMT

Content-Type: text/html; charset=utf-8

Cache-Control: max-age=600, public

X-Ua-Compatible: IE=Edge

X-Request-Id: 391d702c-8062-4068-8187-b1e7c4d49bb8

X-Runtime: 1.077676

X-Content-Digest: 829cb4ba20376043707a20f34957dd6fb3012824

Content-Length: 6205

Age: 5

X-Rack-Cache: fresh

Server: WEBrick/1.3.1 (Ruby/2.0.0/2012-12-10)

Connection: Keep-Alive

curl --silent --dump - --output /dev/null http://localhost:3000/ -H 'If-None-Match: "1c3e833cf0a378d3337f01528bb0a240"'

HTTP/1.1 304 Not Modified

X-Frame-Options: SAMEORIGIN

X-Xss-Protection: 1; mode=block

X-Content-Type-Options: nosniff

X-Xhr-Current-Location: /

Etag: "1c3e833cf0a378d3337f01528bb0a240"

Date: Mon, 10 Dec 2012 01:01:06 GMT

Cache-Control: max-age=600, public

X-Ua-Compatible: IE=Edge

X-Request-Id: 391d702c-8062-4068-8187-b1e7c4d49bb8

X-Runtime: 1.077676

X-Content-Digest: 829cb4ba20376043707a20f34957dd6fb3012824

Age: 5

X-Rack-Cache: fresh

Server: WEBrick/1.3.1 (Ruby/2.0.0/2012-12-10)

Connection: Keep-Alive

25.1 rack 21.2 Form Helpers