Undefined local variable or `flash 'method for # <Devise :: OmniauthCallbacksController: 0x007fb5d1741e48>

Question

I am creating a Rails-API using Omniauth-facebook and Devise-token-auth with Angular and ng-token-auth for the interface. However, when I log in with facebook, I get an error:

undefined local variable or method `flash' for #<Devise::OmniauthCallbacksController:0x007fd027a51e10> 

Omniauth seems to automatically use the Flash middleware, but rails-api does not enable this, and I unsuccessfully disabled flash using omniauth. My configuration is as follows:

application.rb:

  require File.expand_path('../boot', __FILE__) require "rails" # Pick the frameworks you want: require "active_model/railtie" require "active_job/railtie" require "active_record/railtie" require "action_controller/railtie" require "action_mailer/railtie" require "action_view/railtie" require "sprockets/railtie" # require "rails/test_unit/railtie" # Require the gems listed in Gemfile, including any gems # you've limited to :test, :development, or :production. Bundler.require(*Rails.groups) module PathfinderApi class Application < Rails::Application config.active_record.raise_in_transactional_callbacks = true config.middleware.insert_before 0, "Rack::Cors" do allow do origins '*' resource '*', :headers => :any, :methods => [:get, :post, :options] end end config.api_only = true config.middleware.use ActionDispatch::Flash config.middleware.use ActionDispatch::Cookies config.middleware.use ActionDispatch::Session::CookieStore end end 

devise_token_auth.rb:

 DeviseTokenAuth.setup do |config| Rails.application.secrets.facebook_app_secret config.change_headers_on_each_request = true end 

devise.rb:

 Devise.setup do |config| config.navigational_formats = [:json] end 

omniauth.rb:

 Rails.application.config.middleware.use OmniAuth::Builder do provider :facebook, ENV['APP_KEY'], ENV['APP_SECRET'] end 

I was unable to disable the flash error:

 config.navigational_formats = [:json] 

and dev / tomniauth still uses the Flash middleware and throws an error, any help is appreciated!

Answer 1

There was the same problem. I was looking for development source code for "flash". Found about 17 matches using set_flash_message! (with an exclamation mark), with the exception of the failure method in the OmniauthCallbacksController , which uses set_flash_message (without an exclamation mark). Looking at the definition, we see:

\ application \ controllers \ Develops \ omniauth_callbacks_controller.rb

 # Sets flash message if is_flashing_format? equals true def set_flash_message!(key, kind, options = {}) if is_flashing_format? set_flash_message(key, kind, options) end end 

\ Lib \ Develop \ Controllers \ helpers.rb

 def is_flashing_format? is_navigational_format? end def is_navigational_format? Devise.navigational_formats.include?(request_format) end 

The actual flash message is generated in the method without an exclamation mark (I would do it the other way ...). The missing exclamation mark is the reason that setting navigational_formats , as indicated in other solutions, does not work here.

Conclusion: they forgot the exclamation mark.

Fix : monkey-plan failure method from OmniauthCallbacksController . Do this in the initializer, for example, in

\ Config \ Initializers \ devise.rb

 Rails.application.config.to_prepare do # to_prepare ensures that the monkey patching happens before the first request Devise::OmniauthCallbacksController.class_eval do # reopen the class def failure # redefine the failure method set_flash_message! :alert, :failure, kind: OmniAuth::Utils.camelize(failed_strategy.name), reason: failure_message redirect_to after_omniauth_failure_path_for(resource_name) end end end 

Answer 2

Had the same problem in Rails (5.0.0.1) + devise_token_auth (0.1.39).

Besides overriding in @Koen's answer, in my case the following addition is also needed:

 # in config/application.rb config.middleware.use ActionDispatch::Cookies