Making Generators in Rails

http://railscasts.com/episodes/218-making-generators-in-rails-3?view=asciicast

class LayoutGenerator < Rails::Generators::Base
  source_root File.expand_path('../templates', __FILE__)
  argument :layout_name, :type => :string, :default => "application"
  class_option :stylesheet, :type => :boolean, :default => true, :description => "Include stylesheet file"

  def generate_layout
    copy_file "stylesheet.css", "public/stylesheets/#{file_name}.css" if options.stylesheet?
    template "layout.html.erb", "app/views/layouts/#{file_name}.html.erb"
  end

  private
  def file_name
    layout_name.underscore
  end

end

every public method in the class (Rails::Generators::Base) will be executed when the generator runs

• arguments optional:  we can define a default value for each argument. We’ll add a layout_name argument with a default value of application
• template method: which takes similar arguments to copy_file but which will parse any erb in the template before copying it to the destination directory
• class_option: the ability to pass an option that will stop the stylesheet file being generated. We can do this by using the class_option method