deviseのコードを少し読んだ

code: Ruby

# Define authentication filters and accessor helpers based on mappings.

# These filters should be used inside the controllers as before_actions,

# so you can control the scope of the user who should be signed in to

# access that specific controller/action.

# Example:

#

# Roles:

# User

# Admin

#

# Generated methods:

# authenticate_user! # Signs user in or redirect

# authenticate_admin! # Signs admin in or redirect

# user_signed_in? # Checks whether there is a user signed in or not

# admin_signed_in? # Checks whether there is an admin signed in or not

# current_user # Current signed in user

# current_admin # Current signed in admin

# user_session # Session data available only to the user scope

# admin_session # Session data available only to the admin scope

#

# Use:

# before_action :authenticate_user! # Tell devise to use :user map

# before_action :authenticate_admin! # Tell devise to use :admin map

#

mapping = mapping.name

class_eval <<-METHODS, __FILE__, __LINE__ + 1

def authenticate_#{mapping}!(opts = {})

warden.authenticate!(opts) if !devise_controller? || opts.delete(:force)

end

!!current_#{mapping}

end

def current_#{mapping}

@current_#{mapping} ||= warden.authenticate(scope: :#{mapping})

end

current_#{mapping} && warden.session(:#{mapping})

end

METHODS

ActiveSupport.on_load(:action_controller) do

if respond_to?(:helper_method)

helper_method "current_#{mapping}", "#{mapping}_signed_in?", "#{mapping}_session"

end

end

end

code: Ruby

# Small method that adds a mapping to Devise.

def self.add_mapping(resource, options)

mapping = Devise::Mapping.new(resource, options)

@@default_scope ||= mapping.name

@@helpers.each { |h| h.define_helpers(mapping) }

mapping

end

code: Ruby

# Responsible for handling devise mappings and routes configuration. Each

# resource configured by devise_for in routes is actually creating a mapping

# object. You can refer to devise_for in routes for usage options.

#

# The required value in devise_for is actually not used internally, but it's

# inflected to find all other values.

#

# map.devise_for :users

#

# # is the scope used in controllers and warden, given in the route as :singular.

#

# # how the mapping should be search in the path, given in the route as :as.

#

# # is the class to be loaded from routes, given in the route as :class_name.

#

# # is the modules included in the class

#

code: Ruby

def devise_for(*resources)

@devise_finalized = false

raise_no_secret_key unless Devise.secret_key

options = resources.extract_options!

resources.map!(&:to_sym)

resources.each do |resource|

mapping = Devise.add_mapping(resource, options)

begin

raise_no_devise_method_error!(mapping.class_name) unless mapping.to.respond_to?(:devise)

rescue NameError => e

raise unless mapping.class_name == resource.to_s.classify

next

rescue NoMethodError => e

raise unless e.message.include?("undefined method `devise'")

raise_no_devise_method_error!(mapping.class_name)

end

unless mapping.omniauthable?

raise ArgumentError, "Mapping omniauth_callbacks on a resource that is not omniauthable\n" \

end

end

routes = mapping.used_routes

devise_scope mapping.name do

with_devise_exclusive_scope mapping.fullpath, mapping.name, options do

routes.each { |mod| send("devise_#{mod}", mapping, mapping.controllers) }

end

end

end

end

この記事にもっと詳しく書かれていた

では、なぜ動的に定義されたメソッドがすべてのコントローラーで使えるようになるかというと、ApplicationControllerにincludeされる、Devise::Controllers::Helpersにメソッドが作成されるからっぽい

ただ、これコード上どうApplicationControllerにモジュールがincludeされることになるかっていうのがよくわかってない...