Rails 5、#<Devise on line devise_parameter_sanitizer.forの未定義メソッド `for '
Rails 5を使用しています 新しいフィールドusernameをモデルUserに追加しました。 class Users::RegistrationsController < Devise::RegistrationsController before_action :configure_permitted_parameters protected def configure_permitted_parameters devise_parameter_sanitizer.for(:sign_up).push(:username) end end 登録中にエラーが表示されます:#の未定義メソッド「for」フォーク 痕跡: NoMethodError(#の未定義メソッド「for」ですか?フォーク?): app/controllers/users/registrations_controller.rb:7:in `configure_permitted_parameters' Rendering /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout Rendering /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_source.html.erb Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_source.html.erb (5.0ms) Rendering /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (2.9ms) Rendering /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.2ms) Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout (118.1ms) 誰が助けることができますか?この問題をどのように解決しますか?