Rails generators are an essential tool if you plan to improve your workflow. With this guide you will learn how to create generators and customize existing ones.

http://guides.rubyonrails.org/generators.html#creating-generators-with-generators

rails generate generator --help
rails generate generator setup_config

First, notice that we are inheriting from Rails::Generators::NamedBase instead of Rails::Generators::Base. This means that our generator expects at least one argument, which will be the name of the initializer, and will be available in our code in the variable name.

define SetupConfigGenerator

class SetupConfigGenerator < Rails::Generators::Base
  desc "Creates nginx, unicorn, mongoid etc configuration file"
  source_root File.expand_path('../templates', __FILE__)

  argument :app_name, type: :string, optional: true, default: "#{Rails::Application.subclasses.first.parent.to_s.underscore}"

  class_option :app_root,     type: :string, desc: "The Root directory for current application", default: "#{Rails.root}"
  class_option :unicorn_port, type: :string, desc: "The port unicorn use", default: "7788"
  class_option :unicorn_worker_processes, type: :string, desc: "sets the current number of worker_processes to nr", default: 5


  def create_mongoid_yml
    copy_file 'mongoid.yml', File.join('config', "mongoid.yml")
  end

  def create_nginx_config
    template 'nginx.conf', File.join('config', "nginx.conf")
  end

  def create_unicorn_config
    template 'unicorn.conf.rb', File.join('config', "unicorn.conf.rb")
    template 'unicorn_init.sh', File.join('config', "unicorn_init.sh")
  end
end

sudo ln -nfs /home/gxdevelop/dev/guanxime_mobile_felix/config/nginx.conf /etc/nginx/conf.d/guanxime_mobile_felix.conf

sudo ln -nfs /home/gxdevelop/dev/guanxime_mobile_felix/config/unicorn_init.sh /etc/init.d/guanxime_mobile_felix

rails g setup_config guanxime_mobile_felix --unicorn-port=7890

class SetupConfigGenerator < Rails::Generators::NamedBase

The class created by the generator inherits from Rails::Generators::NamedBase. This means that a name will be required when running the generator in the same way as we had to provide a name when we ran the generator generator. We can see this by running our new generator with the --help option.

class SetupConfigGenerator < Rails::Generators::Base

We want the NAME option to be optional and to have a default of application. We can do this by having the class inherit from Rails::Generators::Base, instead of NamedBase. This will make all of the arguments optional and therefore give us more flexibility to customize the generator to our needs.

We can define the arguments that the generator takes by using the argument method. Defining our own arguments instead of using the default NAME option means that we can define a default value for each argument. We’ll add a layout_name argument with a default value of application.

jhjguxin/rails_generate_generate.md

define SetupConfigGenerator