railsのgem deviseのログインページを開くコントローラを読解してみた

def new
  self.resource = resource_class.new(sign_in_params)
  clean_up_passwords(resource)
  yield resource if block_given?
  respond_with(resource, serialize_options(resource))
end

self.resource = resource_class.new(sign_in_params)

clean_up_passwords(resource)

yield resource if block_given?

def new
  super
end

def new
  super { |resource| ... }
end

  respond_with(resource, serialize_options(resource))

# File actionpack/lib/action_controller/metal/mime_responds.rb, line 323
    def respond_with(*resources, &block)
      raise "In order to use respond_with, first you need to declare the formats your "              "controller responds to in the class level" if self.class.mimes_for_respond_to.empty?

      if collector = retrieve_collector_from_mimes(&block)
        options = resources.size == 1 ? {} : resources.extract_options!
        options[:default_response] = collector.response
        (options.delete(:responder) || self.class.responder).call(self, resources, options)
      end
    end

class DeviseController < Devise.parent_controller.constantize

def resource_class
  devise_mapping.to
end

def devise_mapping
  @devise_mapping ||= request.env["devise.mapping"]
end

class Mapping #:nodoc:
  attr_reader :singular, :scoped_path, :path, :controllers, :path_names,
              :class_name, :sign_out_via, :format, :used_routes, :used_helpers,
              :failure_app, :router_name

def to
  @klass.get
end