Rails无法自动加载常量

Question

I have the following folder structure:

- models/
  - mappings/
    - user.rb
  - mapping.rb
  - service.rb
  - user.rb
  - ...

In mappings/user.rb, I have the following:

module Mappings
  class User < Mapping

  end
end

And mapping.rb is:

class Mapping < ActiveRecord::Base

end

In config/application.rb, I am autoloading the models as follows:

config.autoload_paths += %W(#{config.root}/lib #{config.root}/app/presenters)

Unfortunately, I am getting this load_missing_constant error:

/home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:481:in `load_missing_constant': Unable to autoload constant User, expected /vagrant/app/models/mappings/user.rb to define it (LoadError)

Any help would be greatly appreciated. I'm not sure what I'm missing!

UPDATE:

Full trace:

16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:180:in const_missing' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/inflector/methods.rb:238:in const_missing' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/inflector/methods.rb:238:in const_get' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/inflector/methods.rb:238:in block in constantize' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/inflector/methods.rb:236:in block in constantize' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/inflector/methods.rb:236:in each' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/inflector/methods.rb:236:in inject' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/inflector/methods.rb:236:in inject' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/inflector/methods.rb:236:in constantize' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:552:in get' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:583:in get' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:583:in constantize' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise.rb:302:in get' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/mapping.rb:80:in get' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/mapping.rb:80:in to' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/mapping.rb:75:in modules' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/mapping.rb:92:in modules' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/mapping.rb:92:in routes' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/mapping.rb:159:in default_used_route' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/mapping.rb:69:in default_used_route' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/mapping.rb:69:in initialize' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise.rb:336:in new' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise.rb:336:in new' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise.rb:336:in add_mapping' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/rails/routes.rb:224:in block in devise_for' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/rails/routes.rb:223:in block in devise_for' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/rails/routes.rb:223:in each' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/devise-3.4.1/lib/devise/rails/routes.rb:223:in devise_for' 16:53:48 jobs.1 | from /vagrant/config/routes.rb:93:in devise_for' 16:53:48 jobs.1 | from /vagrant/config/routes.rb:93:in block in ' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/actionpack-4.1.9/lib/action_dispatch/routing/route_set.rb:344:in instance_exec' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/actionpack-4.1.9/lib/action_dispatch/routing/route_set.rb:344:in instance_exec' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/actionpack-4.1.9/lib/action_dispatch/routing/route_set.rb:344:in eval_block' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/actionpack-4.1.9/lib/action_dispatch/routing/route_set.rb:322:in draw' 16:53:48 jobs.1 | from /vagrant/config/routes.rb:1:in draw' 16:53:48 jobs.1 | from /vagrant/config/routes.rb:1:in ' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:241:in load' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:241:in load' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:241:in block in load' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:232:in load_dependency' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:241:in load_dependency' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:241:in load' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:40:in block in load_paths' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:40:in block in load_paths' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:40:in each' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:40:in load_paths' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:16:in load_paths' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:16:in reload!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:26:in block in updater' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/file_update_checker.rb:75:in block in updater' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/file_update_checker.rb:75:in call' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/file_update_checker.rb:75:in execute' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:27:in execute' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:27:in updater' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/routes_reloader.rb:7:in execute_if_updated' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/finisher.rb:71:in execute_if_updated' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application/finisher.rb:71:in block in ' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/initializable.rb:30:in instance_exec' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/initializable.rb:30:in instance_exec' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/initializable.rb:30:in run' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/initializable.rb:55:in block in run_initializers' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:226:in block in run_initializers' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:226:in block in tsort_each' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:348:in block (2 levels) in each_strongly_connected_component' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:427:in block (2 levels) in each_strongly_connected_component' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:427:in each_strongly_connected_component_from' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:347:in block in each_strongly_connected_component' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:345:in block in each_strongly_connected_component' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:345:in each' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:345:in call' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:345:in call' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:345:in each_strongly_connected_component' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:224:in tsort_each' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:205:in tsort_each' 16:53:48 jobs.1 | from /home/vagrant/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/tsort.rb:205:in tsort_each' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/initializable.rb:54:in run_initializers' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application.rb:300:in run_initializers' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application.rb:300:in initialize!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/railtie.rb:194:in public_send' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/railtie.rb:194:in public_send' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/railtie.rb:194:in method_missing' 16:53:48 jobs.1 | from /vagrant/config/environment.rb:8:in <top (required)>' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:247:in <top (required)>' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:247:in require' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:247:in block in require' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:232:in block in require' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:232:in load_dependency' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/activesupport-4.1.9/lib/active_support/dependencies.rb:247:in require' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application.rb:276:in require' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/application.rb:276:in require_environment!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands/runner.rb:52:in <top (required)>' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands/commands_tasks.rb:128:in <top (required)>' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands/commands_tasks.rb:128:in require' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands/commands_tasks.rb:128:in require_command!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands/commands_tasks.rb:95:in require_command!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands/commands_tasks.rb:95:in require_command!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands/commands_tasks.rb:95:in runner' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands/commands_tasks.rb:40:in run_command!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands.rb:17:in run_command!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands.rb:17:in run_command!' 16:53:48 jobs.1 | from /home/vagrant/.rvm/gems/ruby-2.1.1/gems/railties-4.1.9/lib/rails/commands.rb:17:in ' 16:53:48 jobs.1 | from bin/rails:8:in require' 16:53:48 jobs.1 | from bin/rails:8:in require' 16:53:48 jobs.1 | from bin/rails:8:in '

So it looks like the issue is because I have to classes named User , even though one is namespaced inside a Module.

Answer 1

I believe it's because you're defining the User class within the Mapping module. It looks at user.rb , doesn't see the User class and errors out. Try removing the module call and see if that works.

Edit: In response to the comment, perhaps you should make that explicit in the class name then. Mappings::User . You'll likely need to inherit it accordingly.