Devise+Twitterのログイン

環境

• Ruby 2.5.0
• Rails 5.1.2

---

やり方

• 以下のGemを入れる

 gem 'devise'
 gem 'omniauth-twitter'
 gem 'omniauth'

• 次に、以下のコマンドを実行

> rails g devise:install

> rails g devise User
 

• db/migrate/***_devise_create_users.rbの以下を編集し、
  rails db:migrateを実行

      ## Database authenticatable
      t.string :provider, null: false
      t.string :uid, null: false
      t.string :image, null: false
      t.string :name, null: false
　   
      ## Rememberable
      t.datetime :remember_created_at
      t.string :remember_token
      
      # 適度にindexを追加
      add_index :users, [:provider, :uid, :name], unique: true

• app/models/user.rbを下記のように編集

devise :rememberable, :trackable, :omniauthable

• app/controllers/users/omniauth_callbacks_controller.rbを作成

class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
  include Devise::Controllers::Rememberable

  def twitter
    auth = request.env['omniauth.auth']
    
    user = User.find_or_create_by(
      provider: auth.provider,
      uid: auth.uid,
      name: auth.info.name
    )
   
    remember_me(user)
    
    sign_in_and_redirect user, event: :authentication
  end
end

• ルーティングを編集するconfing/routes.rb

  devise_for :users, controllers: {
    omniauth_callbacks: 'users/omniauth_callbacks'
  }

  devise_scope :user do
    delete :sign_out, to: 'devise/session#destroy', as: :destroy_user_session
  end

• APIを挿入する

config.omniauth :twitter, 'API', 'secret'

• Viewsにこれを挿入する

<% if user_signed_in? %>
  <%= link_to 'Sign out', destroy_user_session_path, method: :delete %>
  <%= current_user.name %>
  <img src="<%= current_user.image %>" width="30px" height="30px" />
<% else %>
  <%= link_to 'Sign in', user_twitter_omniauth_authorize_path %>
<% end %>

読みづらいけどこんな感じにできました

---

参照元post.simplie.jp