rails auth scaffold

application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery
  helper_method :current_user

  def current_user
    @current_user ||= User.find_by_auth_token(cookies.signed[:auth_token]) if cookies[:auth_token]
  end

  def authenticate_user!
    redirect_to login_url unless current_user
  end
end

gistfile1.txt

rails g model user email:string password_digest:string auth_token:string
rails g controller users new create
rails g controller sessions create
rake db:migrate

layoutsapplication.html.erb

<% if current_user %>
  Logged in as <%= current_user.email %>.
  <%= link_to "Log out", logout_path %>
<% else %>
  <%= link_to "Sign up", signup_path %> or
  <%= link_to "log in", login_path %>.
<% end %>

modelsuser.rb

class User < ActiveRecord::Base
  has_secure_password

  attr_accessible :email, :password, :password_confirmation

  before_create { generate_token(:auth_token) }

  def generate_token(column)
    begin
      self[column] = SecureRandom.urlsafe_base64
    end while User.exists?(column => self[column])
  end

  def to_s
    email
  end
end

routes.rb

get "logout" => "sessions#destroy", :as => "logout"
get "login" => "sessions#new", :as => "login"
get "signup" => "users#new", :as => "signup"
resources :users
resources :sessions

sessions_controller.rb

class SessionsController < ApplicationController
  def new
  end

  def create
    user = User.find_by_email params[:email]
    if user && user.authenticate(params[:password])
      if params[:remember_me]
        cookies.signed.permanent[:auth_token] = user.auth_token
      else
        cookies.signed[:auth_token] = user.auth_token
      end
      redirect_to root_url
    else
      flash.now.alert = "Invalid email or password"
      render :new
    end
  end

  def destroy
    cookies.delete :auth_token
    redirect_to root_url, :notice => "Logged out successfully."
  end
end

sessionsnew.html.erb

<h1>Log in</h1>

<%= form_tag sessions_path do %>
  <p>
    <%= label_tag :email %><br />
    <%= text_field_tag :email, params[:email] %>
  </p>
  <p>
    <%= label_tag :password %><br />
    <%= password_field_tag :password %>
  </p>
  <div class="field">
    <%= check_box_tag :remember_me, 1, params[:remember_me] %>
    <%= label_tag :remember_me %>
  </div>
  <p class="button"><%= submit_tag "Log in" %></p>
<% end %>

users_controller.rb

class UsersController < ApplicationController
  expose :user

  def new
  end

  def create
    if user.save
      cookies.signed.permanent[:auth_token] = user.auth_token
      redirect_to root_url, :notice => "Signed up!"
    else
      render :new
    end
  end
end

usersnew.html.erb

<h1>Sign up</h1>
<%= form_for user do |f| %>
  <% if user.errors.any? %>
    <div class="error_messages">
      <h2>Form is invalid</h2>
      <ul>
        <% for message in user.errors.full_messages %>
          <li><%= message %></li>
        <% end %>
      </ul>
    </div>
  <% end %>
  <div class="field">
    <%= f.label :email %>
    <%= f.text_field :email %>
  </div>
  <div class="field">
    <%= f.label :password %>
    <%= f.password_field :password %>
  </div>
  <div class="field">
    <%= f.label :password_confirmation %>
    <%= f.password_field :password_confirmation %>
  </div>
  <div class="actions"><%= f.submit %></div>
<% end %>