Rails チュートリアル 1章 勉強メモ13

Rails チュートリアル

Rails チュートリアルの勉強メモ

railstutorial.jp

rails server を追ってみる

bin/rails

- hello_app/bin/rails

     1: #!/usr/bin/env ruby
     2: begin
     3:   load File.expand_path('../spring', __FILE__)
     4: rescue LoadError => e
     5:   raise unless e.message.include?('spring')
     6: end
     7: APP_PATH = File.expand_path('../config/application', __dir__)
     8: require_relative '../config/boot'
     9: require 'rails/commands'
  • require 'rails/commands' から読む

rails/commands

require "rails/command"
  
aliases = {
  "g"  => "generate",
  "d"  => "destroy",
  "c"  => "console",
  "s"  => "server",
  "db" => "dbconsole",
  "r"  => "runner",
  "t"  => "test"
}

command = ARGV.shift
command = aliases[command] || command

Rails::Command.invoke command, ARGV
  • aliases で コマンドの省略に対応
  • Rails::Command.invoke command, ARGV でコマンド実行

  • invoke で server コマンドを見つけて実行

    • Rails::Command::ServerCommand

  • thor/command.rb の run にて

[13] pry(#<Thor::Command>)> instance.method(:server).source_location
=> ["$HOME/.rbenv/versions/2.6.2/lib/ruby/gems/2.6.0/gems/railties-5.1.7/lib/rails/commands/server/server_command.rb", 128]
[14] pry(#<Thor::Command>)> instance.method(:server).original_name
=> :perform

gems/railties-5.1.7/lib/rails/commands/server/server_command.rb @ line 129 Rails::Command::ServerCommand#perform:

    128: def perform
 => 129:   set_application_directory!
    130:   Rails::Server.new(server_options).tap do |server|
    131:     # Require application after server sets environment to propagate
    132:     # the --environment option.
    133:     require APP_PATH
    134:     Dir.chdir(Rails.application.root)
    135:     server.start
    136:   end
    137: end
  • set_application_directory! をみる
gems/railties-5.1.7/lib/rails/command/actions.rb @ line 8 Rails::Command::Actions#set_application_directory!:

    7: def set_application_directory!
 => 8:   Dir.chdir(File.expand_path("../../", APP_PATH)) unless File.exist?(File.expand_path("config.ru"))
    9: end

  • config.ru がないところにいるのであれば rails アプリのディレクトリへ戻る

    • APP_PATH = (rails new したとこ)/hello_app/config/application"
    • File.expand_path("../../", APP_PATH) = (rails new したとこ)/hello_app

  • Rails::Server.new(server_options).tap

  • tap について少し調べた

tap (Object) - Rubyリファレンス

tap 面白いよ tap - Qiita

  • ブロックにレシーバ自身を入れてブロックを実行するらしい
  • ここでは Rails::Server.new(server_options) をブロックに入れている
[1] pry(#<Rails::Command::ServerCommand>)> server
=> #<Rails::Server:0x00007fde42bedb60
 @default_options=
  {:user_supplied_options=>[],
   :server=>nil,
   :log_stdout=>true,
   :Port=>3000,
   :Host=>"localhost",
   :DoNotReverseLookup=>true,
   :config=>"config.ru",
   :environment=>"development",
   :daemonize=>false,
   :pid=>"(rails newしたとこ)/hello_app/tmp/pids/server.pid",
   :caching=>nil,
   :restart_cmd=>"bin/rails server  "},
 @ignore_options=[],
 @options=
  {:user_supplied_options=>[],
   :server=>nil,
   :log_stdout=>true,
   :Port=>3000,
   :Host=>"localhost",
   :DoNotReverseLookup=>true,
   :config=>"config.ru",
   :environment=>"development",
   :daemonize=>false,
   :pid=>"(rails newしたとこ)/hello_app/tmp/pids/server.pid",
   :caching=>nil,
   :restart_cmd=>"bin/rails server  "},
 @use_default_options=false>
  • APP_PATH = hello_app/config/application
require_relative 'boot'
  
require 'rails/all'

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module HelloApp
  class Application < Rails::Application
    # Initialize configuration defaults for originally generated Rails version.
    config.load_defaults 5.1

    # Settings in config/environments/* take precedence over those specified here.
    # Application configuration should go into files in config/initializers
    # -- all .rb files in that directory are automatically loaded.
  end
end
  • アプリの root へ移動し、server をスタート
  • 奥までは追えない気がしたので一旦 rails チュートリアルに戻る

おまけ server.start

gems/railties-5.1.7/lib/rails/commands/server/server_command.rb @ line 38 Rails::Server#start:

    37: def start
 => 38:   print_boot_information
    39:   trap(:INT) { exit }
    40:   create_tmp_directories
    41:   setup_dev_caching
    42:   log_to_stdout if options[:log_stdout]
    43: 
    44:   super
    45: ensure
    46:   # The '-h' option calls exit before @options is set.
    47:   # If we call 'options' with it unset, we get double help banners.
    48:   puts "Exiting" unless @options && options[:daemonize]
    49: end