thash/add_name_and_icon_to_users.rb

## add_name_and_icon_to_users.rb
class AddNameAndIconToUsers < ActiveRecord::Migration
  def change
    add_column :users, :name, :string
    add_column :users, :icon, :string
  end
end

## delete_posts.sql
$ sqlite3 db/development.sqlite3
sqlite> delete from posts;

## gem.rb
gem 'sorcery'

## gene_con.sh
$ bundle exec rails generate controller users

## install.sh
$ bundle exec rails generate sorcery:install
      create  config/initializers/sorcery.rb
    generate  model User --skip-migration
      invoke  active_record
      create    app/models/user.rb
      invoke    test_unit
      create      test/models/user_test.rb
      create      test/fixtures/users.yml
      insert  app/models/user.rb
      insert  app/models/user.rb
      create  db/migrate/20140423163942_sorcery_core.rb

## layout.erb
<body>

  <div id="sub">
    <% if logged_in? %>
      <%= image_tag current_user.icon, width: 50, height: 50 %>
      <%= current_user.name %> でログイン中
    <% else %>
      <div id="login_form">
        <%= form_tag signin_users_path, class: 'user_form' do %>
        <label for="email">email:</label><%= text_field_tag :email %><br />
        <label for="password">password:</label><%= password_field_tag :password %><br />
        <div class="actions"><%= submit_tag 'ログイン' %></div>
        <% end %>
        <br />
        <div style="clear: both;"></div>
        もしくは
        <%= link_to '新規登録', new_user_path %>
      </div>
    <% end %>
  </div>
  <div id="main">
    <%= yield %>
  </div>

</body>

## logout.erb
...
<div id="sub">
  <% if logged_in? %>
    <%= image_tag current_user.icon, width: 50, height: 50 %>
    <%= current_user.name %> でログイン中
    <br /><br />
    <%= link_to 'ログアウト', signout_users_path, method: :delete %>
  <% else %>
  ...

## migrate.sh
$ bundle exec rake db:migrate

## models_user.rb
class User < ActiveRecord::Base
  authenticates_with_sorcery!
end

## new.html.erb
<%= link_to '投稿一覧へ', posts_path %><br /><br />

<%= form_for @user, class: 'user_form' do |f| %>
  <label for="name">name:</label> <%= f.text_field :name %><br />
  <label for="email">email:</label> <%= f.text_field :email %><br />
  <label for="password">password:</label> <%= f.password_field :password %><br />
  <label for="icon">icon:</label> <%= f.text_field :icon %><br />
  <div class="actions"><%= f.submit 'ユーザ登録' %></div>
<% end %>

## new_migration.sh
$ bundle exec rails g migration AddNameAndIconToUsers

## post_params.rb
class PostsController < ApplicationController
  #...
  def post_params
    params.require(:post).permit(:body).merge(user_id: current_user.id)
  end

## posts_with_users.erb
  ....
    <% @posts.each do |post| %>
      <tr>
        <td class="icon"><%= image_tag post.user.icon, width: 20, height: 20 %></td>
        <td class="name"><%= post.user.name %></td>
        <td class="body">「<%= post.body %>」</td>
        <td class="created_at"><%= link_to post.created_at, post %></td>
        <% if logged_in? && current_user == post.user %>
          <td class="destroy"><%= link_to '×', post, method: :delete, data: { confirm: 'Are you sure?' } %></td>
        <% end %>
      </tr>
    <% end %>

## relations.rb
# app/models/user.rb
class User < ActiveRecord::Base
  authenticates_with_sorcery!
  has_many :posts
end

# app/models/post.rb
class Post < ActiveRecord::Base
  belongs_to :user
end

## render_form.erb
<% if logged_in? %>
  <%= render 'form' %>
<% end %>

## require_login.rb
class PostsController < ApplicationController
  # ...
  before_action :require_login, only: [:create, :destroy]

## routes.rb
Rwitter::Application.routes.draw do
  # ...
  resources :users, only: [:new, :create] do
    collection do
      post   :signin
      delete :signout
    end
  end

## routes.sh
$ bundle exec rake routes | grep users
 signin_users POST   /users/signin(.:format)   users#signin
signout_users DELETE /users/signout(.:format)  users#signout
        users POST   /users(.:format)          users#create
     new_user GET    /users/new(.:format)      users#new

## signin.rb
def signin
  if login(params[:email], params[:password])
    redirect_to root_path, notice: 'ログインしました'
  else
    redirect_to root_path, alert: 'ログインに失敗しました'
  end
end

## signout.rb
def signout
  if logout
    redirect_to root_path, notice: 'ログアウトしました'
  else
    redirect_to root_path, alert: 'ログアウトに失敗しました'
  end
end

## sorcery_core.rb
class SorceryCore < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.string :email,            :null => false
      t.string :crypted_password, :null => false
      t.string :salt,             :null => false

      t.timestamps
    end

    add_index :users, :email, unique: true
  end
end

## user_first.rb
> User.first
  User Load (0.2ms)  SELECT "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT 1
=> #<User id: 1, email: "hash@example.com", crypted_password: "$2a$10$qjnOIDTS8PwyJCnrFO3GIeY1/B57D.djWsTTJg9CRRUv...", salt: "No7XZBLgYRswjszxmjR3", created_at: "2014-04-27 11:36:17", updated_at: "2014-04-27 11:36:17", name: "Hash", icon: "http://www.gravatar.com/avatar/0c4becc8e557c4876120...">

## user_id.rb
# $ bundle exec rails g migration AddUserIdToPosts で作成
class AddUserIdToPosts < ActiveRecord::Migration
  def change
    add_column :posts, :user_id, :integer
  end
end

## users.sql
$ sqlite3 db/development.sqlite3

sqlite> .schema users
CREATE TABLE "users" (
"id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
 "email" varchar(255) NOT NULL,
 "crypted_password" varchar(255) NOT NULL,
 "salt" varchar(255) NOT NULL,
 "created_at" datetime,
 "updated_at" datetime,
 "name" varchar(255),
 "icon" varchar(255));
CREATE UNIQUE INDEX "index_users_on_email" ON "users" ("email");

## users_controller.rb
class UsersController < ApplicationController

  def new
    @user = User.new
  end

  def create
    user = User.new(user_params)
    if user.save
      redirect_to root_path, notice: 'ユーザを作成しました。左のフォームからログインしてください'
    else
      render new_user_path, alert: 'ユーザ登録に失敗しました'
    end
  end

  def signin
    # TODO
  end

  def signout
    # TODO
  end

  private

  def user_params
    params.require(:user).permit(:name, :email, :password, :icon)
  end
end
	class AddNameAndIconToUsers < ActiveRecord::Migration
	def change
	add_column :users, :name, :string
	add_column :users, :icon, :string
	end
	end
	$ bundle exec rails generate sorcery:install
	create config/initializers/sorcery.rb
	generate model User --skip-migration
	invoke active_record
	create app/models/user.rb
	invoke test_unit
	create test/models/user_test.rb
	create test/fixtures/users.yml
	insert app/models/user.rb
	insert app/models/user.rb
	create db/migrate/20140423163942_sorcery_core.rb
	<body>

	<div id="sub">
	<% if logged_in? %>
	<%= image_tag current_user.icon, width: 50, height: 50 %>
	<%= current_user.name %> でログイン中
	<% else %>
	<div id="login_form">
	<%= form_tag signin_users_path, class: 'user_form' do %>
	<label for="email">email:</label><%= text_field_tag :email %><br />
	<label for="password">password:</label><%= password_field_tag :password %><br />
	<div class="actions"><%= submit_tag 'ログイン' %></div>
	<% end %>
	<br />
	<div style="clear: both;"></div>
	もしくは
	<%= link_to '新規登録', new_user_path %>
	</div>
	<% end %>
	</div>
	<div id="main">
	<%= yield %>
	</div>

	</body>
	class User < ActiveRecord::Base
	authenticates_with_sorcery!
	end
	<%= link_to '投稿一覧へ', posts_path %><br /><br />

	<%= form_for @user, class: 'user_form' do \|f\| %>
	<label for="name">name:</label> <%= f.text_field :name %><br />
	<label for="email">email:</label> <%= f.text_field :email %><br />
	<label for="password">password:</label> <%= f.password_field :password %><br />
	<label for="icon">icon:</label> <%= f.text_field :icon %><br />
	<div class="actions"><%= f.submit 'ユーザ登録' %></div>
	<% end %>
	class PostsController < ApplicationController
	#...
	def post_params
	params.require(:post).permit(:body).merge(user_id: current_user.id)
	end
	....
	<% @posts.each do \|post\| %>
	<tr>
	<td class="icon"><%= image_tag post.user.icon, width: 20, height: 20 %></td>
	<td class="name"><%= post.user.name %></td>
	<td class="body">「<%= post.body %>」</td>
	<td class="created_at"><%= link_to post.created_at, post %></td>
	<% if logged_in? && current_user == post.user %>
	<td class="destroy"><%= link_to '×', post, method: :delete, data: { confirm: 'Are you sure?' } %></td>
	<% end %>
	</tr>
	<% end %>
	# app/models/user.rb
	class User < ActiveRecord::Base
	authenticates_with_sorcery!
	has_many :posts
	end

	# app/models/post.rb
	class Post < ActiveRecord::Base
	belongs_to :user
	end
	class PostsController < ApplicationController
	# ...
	before_action :require_login, only: [:create, :destroy]
	Rwitter::Application.routes.draw do
	# ...
	resources :users, only: [:new, :create] do
	collection do
	post :signin
	delete :signout
	end
	end