Railscasts #241 NoMethodError undefined method `[]' for nil:NilClass
There is a NoMethodError in SessionsController#create. The twitter authentication page occurs but the callback URL is not working. The page is not being rendered to the website after twitter authentication. Here is the code in different files.
In routes.rb
Blog::Application.routes.draw do
root :to => "posts#index"
match "/auth/:provider/callback" => "sessions#create"
match "/signout" => "sessions#destroy", :as => :signout
resources :posts
end
In sessions_controller.rb
class SessionsController < ApplicationController
def create
auth = request.env["omniauth.auth"]
user = User.find_by_provider_and_uid(auth["provider"], auth["uid"]) || User.create_with_omniauth(auth)
session[:user_id] = user.id
redirect_to root_url, :notice => "Signed in!"
end
def destroy
session[:user_id] = nil
redirect_to root_url, :notice => "Signed out!"
end
end
In user.rb
class User < ActiveRecord::Base
def self.create_with_omniauth(auth)
create! do |user|
user.provider = auth["provider"]
user.uid = auth["uid"]
user.name = auth["user_info"]["name"]
end
end
end
Full Trace:
app/models/user.rb:6:in `block in create_with_omniauth'
activerecord (3.2.0) lib/active_record/validations.rb:40:in `create!'
app/models/user.rb:3:in `create_with_omniauth'
app/controllers/sessions_controller.rb:4:in `create'
actionpack (3.2.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (3.2.0) lib/abstract_controller/base.rb:167:in `process_action'
actionpack (3.2.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (3.2.0) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (3.2.0) lib/active_support/callbacks.rb:414:in `_run__168269495__process_action__8122527__callbacks'
activesupport (3.2.0) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.0) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
activesupport (3.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.0) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.2.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (3.2.0) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.2.0) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.0) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.0) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.2.0) lib/action_controller/metal/params_wrapper.rb:205:in `process_action'
activerecord (3.2.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (3.2.0) lib/abstract_controller/base.rb:121:in `process'
actionpack (3.2.0) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.2.0) lib/action_controller/metal.rb:203:in `dispatch'
actionpack (3.2.0) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.2.0) lib/action_controller/metal.rb:246:in `block in action'
actionpack (3.2.0) lib/action_dispatch/routing/route_set.rb:66:in `call'
actionpack (3.2.0) lib/action_dispatch/routing/route_set.rb:66:in `dispatch'
actionpack (3.2.0) lib/action_dispatch/routing/route_set.rb:30:in `call'
journey (1.0.4) lib/journey/router.rb:68:in `block in call'
journey (1.0.4) lib/journey/router.rb:56:in `each'
journey (1.0.4) lib/journey/router.rb:56:in `call'
actionpack (3.2.0) lib/action_dispatch/routing/route_set.rb:570:in `call'
omniauth (1.1.4) lib/omniauth/strategy.rb:401:in `call_app!'
omniauth (1.1.4) lib/omniauth/strategy.rb:363:in `callback_phase'
omniauth-oauth (1.0.1) lib/omniauth/strategies/oauth.rb:58:in `callback_phase'
omniauth (1.1.4) lib/omniauth/strategy.rb:226:in `callback_call'
omniauth (1.1.4) lib/omniauth/strategy.rb:182:in `call!'
omniauth (1.1.4) lib/omniauth/strategy.rb:164:in `call'
omniauth (1.1.4) lib/omniauth/builder.rb:49:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
rack (1.4.5) lib/rack/etag.rb:23:in `call'
rack (1.4.5) lib/rack/conditionalget.rb:25:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/head.rb:14:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/flash.rb:242:in `call'
rack (1.4.5) lib/rack/session/abstract/id.rb:210:in `context'
rack (1.4.5) lib/rack/session/abstract/id.rb:205:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/cookies.rb:338:in `call'
activerecord (3.2.0) lib/active_record/query_cache.rb:64:in `call'
activerecord (3.2.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:443:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.0) lib/active_support/callbacks.rb:405:in `_run__208198798__call__80088063__callbacks'
activesupport (3.2.0) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.0) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
activesupport (3.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/reloader.rb:65:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
railties (3.2.0) lib/rails/rack/logger.rb:26:in `call_app'
railties (3.2.0) lib/rails/rack/logger.rb:16:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/request_id.rb:22:in `call'
rack (1.4.5) lib/rack/methodoverride.rb:21:in `call'
rack (1.4.5) lib/rack/runtime.rb:17:in `call'
activesupport (3.2.0) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.4.5) lib/rack/lock.rb:15:in `call'
actionpack (3.2.0) lib/action_dispatch/middleware/static.rb:53:in `call'
railties (3.2.0) lib/rails/engine.rb:479:in `call'
railties (3.2.0) lib/rails/application.rb:220:in `call'
rack (1.4.5) lib/rack/content_length.rb:14:in `call'
railties (3.2.0) lib/rails/rack/log_tailer.rb:14:in `call'
rack (1.4.5) lib/rack/handler/webrick.rb:59:in `service'
/home/sakshi/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/home/sakshi/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/home/sakshi/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
Console:
NoMethodError (undefined method `[]' for nil:NilClass):
app/models/user.rb:6:in `block in create_with_omniauth'
app/models/user.rb:3:in `create_with_omniauth'
app/controllers/sessions_controller.rb:4:in `create'
Answer
In line 6 of app/models/user.rb:
user.name = auth["user_info"]["name"]
The auth hash doesn't have a value for the "user_info" key, so it returns nil; then you try to call the [] method on nil, which raises the exception.
Try adding a p auth in the block to verify the auth hash contents:
class User < ActiveRecord::Base
def self.create_with_omniauth(auth)
create! do |user|
puts "DEBUG " + "=" * 50
p auth
user.provider = auth["provider"]
user.uid = auth["uid"]
user.name = auth["user_info"]["name"]
end
end
end