activeadmin with rails API app errors：Admin :: DashboardController #index中的ArgumentError

Question

I am trying to incorporate active admin with a rails_api app.

Details:

Because it is an API, with no cookies and stuffs, I am using devise_auth_token for authentication ( not devise ).

The authentication is working perfectly. However, I'm now trying to incorporate active admin with this, and followed the steps:

gem 'activeadmin', '1.0.0.pre2'
$ bundle install
$ rails g active_admin:install 
$ rake db:migrate db:seed
$rails server

On going to http://localhost:3000/admin , it blew up with following error:

ArgumentError in Admin::DashboardController#index
wrong number of arguments (given 1, expected 0)

pointing to a line: define_method(name) do in:

 if instance_reader
    remove_possible_method name
    define_method(name) do
      if instance_variable_defined?(ivar)
        instance_variable_get ivar
      else

Note however that going directly to http://localhost:3000/admin/login opens the login page, but after login, it redirects back to http://localhost:3000/admin with same error message.

Gemfile:

gem 'pg'
gem 'devise'
gem 'devise_token_auth'
gem 'omniauth'
gem 'money-rails'
gem 'swagger-docs'
gem 'activeadmin', '1.0.0.pre2'gem 'pg'
gem 'devise'
gem 'devise_token_auth'
gem 'omniauth'
gem 'money-rails'
gem 'swagger-docs'
gem 'activeadmin', '1.0.0.pre2'

Routes.rb:

Rails.application.routes.draw do
  devise_for :admin_users, ActiveAdmin::Devise.config
  ActiveAdmin.routes(self)
  namespace :api do
    namespace :v1 do
      mount_devise_token_auth_for 'User', at: 'auth'
      ...
    end
  end
  root to: "home#index"
end

Dependencies:

• Ruby: 2.3.0
• Rails: 4.2.4
• Active Admin: 1.0.0.pre2
• Rails API: 0.4.0
• Devise: 3.5.6
• Devise token auth: 0.1.37

Stack trace:

ArgumentError (wrong number of arguments (given 1, expected 0)):
  activesupport (4.2.4) lib/active_support/core_ext/class/attribute.rb:106:in `block (2 levels) in class_attribute'
  devise_token_auth (0.1.37) app/controllers/devise_token_auth/concerns/set_user_by_token.rb:21:in `set_user_by_token'
  devise_token_auth (0.1.37) lib/devise_token_auth/controllers/helpers.rb:117:in `current_admin_user'
  devise_token_auth (0.1.37) lib/devise_token_auth/controllers/helpers.rb:105:in `authenticate_admin_user!'
  activeadmin (1.0.0.pre2) lib/active_admin/base_controller.rb:39:in `authenticate_active_admin_user'
  activesupport (4.2.4) lib/active_support/callbacks.rb:432:in `block in make_lambda'
  activesupport (4.2.4) lib/active_support/callbacks.rb:164:in `block in halting'
  activesupport (4.2.4) lib/active_support/callbacks.rb:504:in `block in call'
  activesupport (4.2.4) lib/active_support/callbacks.rb:504:in `each'
  activesupport (4.2.4) lib/active_support/callbacks.rb:504:in `call'
  activesupport (4.2.4) lib/active_support/callbacks.rb:92:in `__run_callbacks__'
  activesupport (4.2.4) lib/active_support/callbacks.rb:778:in `_run_process_action_callbacks'
  activesupport (4.2.4) lib/active_support/callbacks.rb:81:in `run_callbacks'
  actionpack (4.2.4) lib/abstract_controller/callbacks.rb:19:in `process_action'
  actionpack (4.2.4) lib/action_controller/metal/rescue.rb:29:in `process_action'
  actionpack (4.2.4) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
  activesupport (4.2.4) lib/active_support/notifications.rb:164:in `block in instrument'
  activesupport (4.2.4) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
  activesupport (4.2.4) lib/active_support/notifications.rb:164:in `instrument'
  actionpack (4.2.4) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
  actionpack (4.2.4) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
  activerecord (4.2.4) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
  actionpack (4.2.4) lib/abstract_controller/base.rb:137:in `process'
  actionview (4.2.4) lib/action_view/rendering.rb:30:in `process'
  actionpack (4.2.4) lib/action_controller/metal.rb:196:in `dispatch'
  actionpack (4.2.4) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
  actionpack (4.2.4) lib/action_controller/metal.rb:237:in `block in action'
  actionpack (4.2.4) lib/action_dispatch/routing/route_set.rb:76:in `dispatch'
  actionpack (4.2.4) lib/action_dispatch/routing/route_set.rb:45:in `serve'
  actionpack (4.2.4) lib/action_dispatch/journey/router.rb:43:in `block in serve'
  actionpack (4.2.4) lib/action_dispatch/journey/router.rb:30:in `each'
  actionpack (4.2.4) lib/action_dispatch/journey/router.rb:30:in `serve'
  actionpack (4.2.4) lib/action_dispatch/routing/route_set.rb:821:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/flash.rb:260:in `call'
  warden (1.2.6) lib/warden/manager.rb:35:in `block in call'
  warden (1.2.6) lib/warden/manager.rb:34:in `catch'
  warden (1.2.6) lib/warden/manager.rb:34:in `call'
  rack (1.6.4) lib/rack/etag.rb:24:in `call'
  rack (1.6.4) lib/rack/conditionalget.rb:25:in `call'
  rack (1.6.4) lib/rack/head.rb:13:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
  activerecord (4.2.4) lib/active_record/query_cache.rb:36:in `call'
  activerecord (4.2.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:653:in `call'
  activerecord (4.2.4) lib/active_record/migration.rb:377:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
  activesupport (4.2.4) lib/active_support/callbacks.rb:88:in `__run_callbacks__'
  activesupport (4.2.4) lib/active_support/callbacks.rb:778:in `_run_call_callbacks'
  activesupport (4.2.4) lib/active_support/callbacks.rb:81:in `run_callbacks'
  actionpack (4.2.4) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/reloader.rb:73:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
  railties (4.2.4) lib/rails/rack/logger.rb:38:in `call_app'
  railties (4.2.4) lib/rails/rack/logger.rb:20:in `block in call'
  activesupport (4.2.4) lib/active_support/tagged_logging.rb:68:in `block in tagged'
  activesupport (4.2.4) lib/active_support/tagged_logging.rb:26:in `tagged'
  activesupport (4.2.4) lib/active_support/tagged_logging.rb:68:in `tagged'
  railties (4.2.4) lib/rails/rack/logger.rb:20:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/request_id.rb:21:in `call'
  rack (1.6.4) lib/rack/runtime.rb:18:in `call'
  activesupport (4.2.4) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
  rack (1.6.4) lib/rack/lock.rb:17:in `call'
  actionpack (4.2.4) lib/action_dispatch/middleware/static.rb:116:in `call'
  railties (4.2.4) lib/rails/engine.rb:518:in `call'
  railties (4.2.4) lib/rails/application.rb:165:in `call'
  rack (1.6.4) lib/rack/lock.rb:17:in `call'
  rack (1.6.4) lib/rack/content_length.rb:15:in `call'
  rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
  /Users/Sunday/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/webrick/httpserver.rb:140:in `service'
  /Users/Sunday/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/webrick/httpserver.rb:96:in `run'
  /Users/Sunday/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/webrick/server.rb:296:in `block in start_thread'

I am suspecting it may have to do with the fact that rails_api does not include several rails middleware by default... but really, I don't know what it is, or how I can go about it. Please anyone, I need help on this.

Will my combination even work at all?

Answer 1

This is an issue while using the devise_auth_token with active_admin

This is the Work around given in the devise_token_auth gem itself.

For some odd reason, ActiveAdmin extends from your own app's ApplicationController. This becomes a problem if you include the DeviseTokenAuth::Concerns::SetUserByToken concern in your app's ApplicationController.

The solution is to use two separate ApplicationController classes - one for your API, and one for ActiveAdmin. Something like this:

app/controllers/api_controller.rb

API routes extend from this controller

class ApiController < ActionController::Base
  include DeviseTokenAuth::Concerns::SetUserByToken
end

app/controllers/application_controller.rb

leave this for ActiveAdmin, and any other non-api routes

class ApplicationController < ActionController::Base
end

This is the reference

Answer 2

This is defiantly not a very good combo.

Rails API is meant as a scaled down version of Rails for applications which do not have a normal web interface - its faster because it strips out components which are needed for classical web apps such as sessions.

These components are known as middleware.

• http://guides.rubyonrails.org/rails_on_rack.html

ActiveAdmin is a quick and easy web interface for doing CRUD on your models. So that human can edit data by clicking buttons instead of by using an API.

What you might want to do instead is have two separate rails apps - one that serves data via the API and a web app that lets humans use ActiveAdmin. This is a rather common solution when you need a web app but don't want it to burden down your API.

Each would live in its own GIT repository and be served by different servers. You would share components such as models by extracting them into gem(s).