Rails ガイド

$ rails --help
Usage: rails COMMAND [ARGS]

The most common rails commands are:
 generate    Generate new code (short-cut alias: "g")
 console     Start the Rails console (short-cut alias: "c")
 server      Start the Rails server (short-cut alias: "s")
 ...

All commands can be run with -h (or --help) for more information.

In addition to those commands, there are:
 about                               List versions of all Rails ...
 assets:clean[keep]                  Remove old compiled assets
 assets:clobber                      Remove compiled assets
 assets:environment                  Load asset compile environment
 assets:precompile                   Compile all the assets ...
 ...
 db:fixtures:load                    Loads fixtures into the ...
 db:migrate                          Migrate the database ...
 db:migrate:status                   Display status of migrations
 db:rollback                         Rolls the schema back to ...
 db:schema:cache:clear               Clears a db/schema_cache.yml file
 db:schema:cache:dump                Creates a db/schema_cache.yml file
 db:schema:dump                      Creates a db/schema.rb file ...
 db:schema:load                      Loads a schema.rb file ...
 db:seed                             Loads the seed data ...
 db:structure:dump                   Dumps the database structure ...
 db:structure:load                   Recreates the databases ...
 db:version                          Retrieves the current schema ...
 ...
 restart                             Restart app by touching ...
 tmp:create                          Creates tmp directories ...

$ rails new commandsapp
    create
    create README.md
    create Rakefile
    create config.ru
    create .gitignore
    create Gemfile
    create app
    ...
    create  tmp/cache
    ...
        run bundle install

$ cd commandsapp
$ rails server
=> Booting Puma
=> Rails 5.1.0 application starting in development on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.0.2 (ruby 2.3.0-p0), codename: Plethora of Penguin Pinatas
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://localhost:3000
Use Ctrl-C to stop

$ rails server -e production -p 4000

$ rails generate
Usage: rails generate GENERATOR [args] [options]

...
...

Please choose a generator below.

Rails:
  assets
  channel
  controller
  generator
  ...
  ...

$ rails generate controller
Usage: rails generate controller NAME [action action] [options]

...
...

Description:
    ...

    To create a controller within a module, specify the controller name as a path like 'parent_module/controller_name'.

    ...

Example:
    `rails generate controller CreditCards open debit credit close`

    Credit card controller with URLs like /credit_cards/debit.
        Controller: app/controllers/credit_cards_controller.rb
        Test:       test/controllers/credit_cards_controller_test.rb
        Views:      app/views/credit_cards/debit.html.erb [...]
        Helper:     app/helpers/credit_cards_helper.rb

$ rails generate controller Greetings hello
     create  app/controllers/greetings_controller.rb
      route  get 'greetings/hello'
     invoke  erb
     create    app/views/greetings
     create    app/views/greetings/hello.html.erb
     invoke  test_unit
     create    test/controllers/greetings_controller_test.rb
     invoke  helper
     create    app/helpers/greetings_helper.rb
     invoke    test_unit
     invoke  assets
     invoke    scss
     create      app/assets/stylesheets/greetings.scss

class GreetingsController < ApplicationController
  def hello
    @message = "Hello, how are you today?"
  end 
end 

<h1>A Greeting for You!</h1>
<p><%= @message %></p>

$ rails server
=> Booting Puma...

$ rails generate model
Usage:
  rails generate model NAME [field[:type][:index] field[:type][:index]] [options]

...

Active Record options:
      [--migration]            # Indicates when to generate migration
                               # Default: true

...

Description:
    Create rails files for model generator.

$ rails generate scaffold HighScore game:string score:integer
    invoke  active_record
    create    db/migrate/20130717151933_create_high_scores.rb
    create    app/models/high_score.rb
    invoke    test_unit
    create      test/models/high_score_test.rb
    create      test/fixtures/high_scores.yml
    invoke  resource_route
     route    resources :high_scores
    invoke  scaffold_controller
    create    app/controllers/high_scores_controller.rb
    invoke    erb
    create      app/views/high_scores
    create      app/views/high_scores/index.html.erb
    create      app/views/high_scores/edit.html.erb
    create      app/views/high_scores/show.html.erb
    create      app/views/high_scores/new.html.erb
    create      app/views/high_scores/_form.html.erb
    invoke    test_unit
    create      test/controllers/high_scores_controller_test.rb
    invoke    helper
    create      app/helpers/high_scores_helper.rb
    invoke    jbuilder
    create      app/views/high_scores/index.json.jbuilder
    create      app/views/high_scores/show.json.jbuilder
    invoke  test_unit
    create    test/system/high_scores_test.rb
    invoke  assets
    invoke    coffee
    create      app/assets/javascripts/high_scores.coffee
    invoke    scss
    create      app/assets/stylesheets/high_scores.scss
    invoke  scss
   identical    app/assets/stylesheets/scaffolds.scss

$ rails db:migrate
==  CreateHighScores: migrating ===============================================
-- create_table(:high_scores)
   -> 0.0017s
==  CreateHighScores: migrated (0.0019s) ======================================

$ rails server

$ rails console -e staging

$ rails console --sandbox
Loading development environment in sandbox (Rails 5.1.0)
Any modifications you make will be rolled back on exit
irb(main):001:0>

>> app.root_path
=> "/"

>> app.get _
Started GET "/" for 127.0.0.1 at 2014-06-19 10:41:57 -0300
...

>> helper.time_ago_in_words 30.days.ago
=> "about 1 month"

>> helper.my_custom_helper
=> "my custom helper"

$ rails runner "Model.long_running_method"

$ rails runner -e staging "Model.long_running_method"

$ rails runner lib/code_to_be_run.rb

$ rails generate model Oops
      invoke  active_record
      create    db/migrate/20120528062523_create_oops.rb
      create    app/models/oops.rb
      invoke  test_unit
      create      test/models/oops_test.rb
      create      test/fixtures/oops.yml

$ rails destroy model Oops
      invoke  active_record
      remove    db/migrate/20120528062523_create_oops.rb
      remove    app/models/oops.rb
      invoke  test_unit
      remove      test/models/oops_test.rb
      remove      test/fixtures/oops.yml

$ rails about
About your application's environment
Rails version             6.0.0
Ruby version              2.5.0 (x86_64-linux)
RubyGems version          2.7.3
Rack version              2.0.4
JavaScript Runtime        Node.js (V8)
Middleware:               Rack::Sendfile, ActionDispatch::Static, ActionDispatch::Executor, ActiveSupport::Cache::Strategy::LocalCache::Middleware, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, ActionDispatch::RemoteIp, Sprockets::Rails::QuietAssets, Rails::Rack::Logger, ActionDispatch::ShowExceptions, WebConsole::Middleware, ActionDispatch::DebugExceptions, ActionDispatch::Reloader, ActionDispatch::Callbacks, ActiveRecord::Migration::CheckPending, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, Rack::Head, Rack::ConditionalGet, Rack::ETag
Application root          /home/foobar/commandsapp
Environment               development
Database adapter          sqlite3
Database schema version   20180205173523

$ rails notes
(in /home/foobar/commandsapp)
app/controllers/admin/users_controller.rb:
  * [ 20] [TODO] any other way to do this?
  * [132] [FIXME] high priority for next deploy

app/models/school.rb:
  * [ 13] [OPTIMIZE] refactor this code to make it faster
  * [ 17] [FIXME]

$ rails notes --annotations FIXME RELEASE
app/controllers/admin/users_controller.rb:
  * [101] [RELEASE] We need to look at this before next release
  * [132] [FIXME] high priority for next deploy

lib/school.rb:
  * [ 17] [FIXME]

config.annotations.register_tags("DEPRECATEME", "TESTME")

$ rails notes
app/controllers/admin/users_controller.rb:
  * [ 20] [TODO] do A/B testing on this
  * [ 42] [TESTME] this needs more functional tests
  * [132] [DEPRECATEME] ensure this method is deprecated in next release

config.annotations.register_directories("spec", "vendor")

$ rails notes
app/controllers/admin/users_controller.rb:
  * [ 20] [TODO] any other way to do this?
  * [132] [FIXME] high priority for next deploy

lib/school.rb:
  * [ 13] [OPTIMIZE] Refactor this code to make it faster
  * [ 17] [FIXME]

spec/models/user_spec.rb:
  * [122] [TODO] Verify the user that has a subscription works

vendor/tools.rb:
  * [ 56] [TODO] Get rid of this dependency

config.annotations.register_extensions("scss", "sass") { |annotation| /\/\/\s*(#{annotation}):?\s*(.*)$/ }

$ rails notes
app/controllers/admin/users_controller.rb:
  * [ 20] [TODO] any other way to do this?
  * [132] [FIXME] high priority for next deploy

app/assets/stylesheets/application.css.sass:
  * [ 34] [TODO] Use pseudo element for this class

app/assets/stylesheets/application.css.scss:
  * [  1] [TODO] Split into multiple components

lib/school.rb:
  * [ 13] [OPTIMIZE] Refactor this code to make it faster
  * [ 17] [FIXME]

spec/models/user_spec.rb:
  * [122] [TODO] Verify the user that has a subscription works

vendor/tools.rb:
  * [ 56] [TODO] Get rid of this dependency

desc "I am short, but comprehensive description for my cool task"
task task_name: [:prerequisite_task, :another_task_we_depend_on] do
  # マジックをここに書く
  # 有効なRubyコードなら何でも書ける
end 

task :task_name, [:arg_1] => [:prerequisite_1, :prerequisite_2] do |task, args|
  argument_1 = args.arg_1
end

namespace :db do 
  desc "何もしないたすく"
  task :nothing do
    # マジ何もしない
  end 
end 

$ rails task_name
$ rails "task_name[value 1]" # entire argument string should be quoted
$ rails db:nothing

$ mkdir gitapp
$ cd gitapp
$ git init
Initialized empty Git repository in .git/
$ rails new . --git --database=postgresql
      exists
      create  app/controllers
      create  app/helpers
...
...
      create  tmp/cache
      create  tmp/pids
      create  Rakefile
add 'Rakefile'
      create  README.md
add 'README.md'
      create  app/controllers/application_controller.rb
add 'app/controllers/application_controller.rb'
      create  app/helpers/application_helper.rb
...
      create  log/test.log
add 'log/test.log'

$ cat config/database.yml
# PostgreSQL. Versions 9.1 and up are supported.
#
# Install the pg driver:
#   gem install pg
# On macOS with Homebrew:
#   gem install pg -- --with-pg-config=/usr/local/bin/pg_config
# On macOS with MacPorts:
#   gem install pg -- --with-pg-config=/opt/local/lib/postgresql84/bin/pg_config
# On Windows:
#   gem install pg
#       Choose the win32 build.
#       Install PostgreSQL and put its /bin directory on your path.
#
# Configure Using Gemfile
# gem 'pg'
#
default: &default
  adapter: postgresql
  encoding: unicode
  # For details on connection pooling, see Rails configuration guide
  # https://guides.rubyonrails.org/configuring.html#database-pooling
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

development:
  <<: *default
  database: gitapp_development
...
...