#241 Simple OmniAuth (revised)

rails g model user provider uid name
rake db:migrate

gem 'omniauth-twitter'

OmniAuth.config.logger = Rails.logger

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :twitter, ENV['TWITTER_KEY'], ENV['TWITTER_SECRET']
end

match 'auth/:provider/callback', to: 'sessions#create'
match 'auth/failure', to: redirect('/')
match 'signout', to: 'sessions#destroy', as: 'signout'

def create
  user = User.from_omniauth(env["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

def self.from_omniauth(auth)
  where(auth.slice("provider", "uid")).first || create_from_omniauth(auth)
end

def self.create_from_omniauth(auth)
  create! do |user|
    user.provider = auth["provider"]
    user.uid = auth["uid"]
    user.name = auth["info"]["nickname"]
  end
end

private

def current_user
  @current_user ||= User.find(session[:user_id]) if session[:user_id]
end
helper_method :current_user

<% if current_user %>
  Signed in as <%= current_user.name %>!
  <%= link_to "Sign out", signout_path %>
<% else %>
  <%= link_to "Sign in with Twitter", "/auth/twitter" %>
<% end %>