# Gemfile

gem 'bcrypt-ruby'

# config/routes.rb

get 'signup', to: 'users#new', as: 'signup'
get 'login', to: 'sessions#new', as: 'login'
get 'logout', to: 'sessions#destroy', as: 'logout'

resources :users
resources :sessions

# models/user.rb

has_secure_password
attr_accessible :email, :password, :password_confirmation
validates_uniqueness_of :email

# controllers/users_controller.rb

def new
  @user = User.new
end

def create
  @user = User.new(params[:user])
  if @user.save
    session[:user_id] = @user.id
    redirect_to root_url, notice: "Thank you for signing up!"
  else
    render "new"
  end
end

# controllers/sessions_controller.rb

def new
end

def create
  user = User.find_by_email(params[:email])
  if user && user.authenticate(params[:password])
    session[:user_id] = user.id
    redirect_to root_url, notice: "Logged in!"
  else
    flash.now.alert = "Email or password is invalid"
    render "new"
  end
end

def destroy
  session[:user_id] = nil
  redirect_to root_url, notice: "Logged out!"
end

# controllers/application_controller.rb

before_filter :authorize

private

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

def authorize
  redirect_to login_url, alert: "Not authorized" if current_user.nil?
end

# views/users/new.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>
        <% @user.errors.full_messages.each do |message| %>
          <li><%= message %></li>
        <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :email %><br />
    <%= f.text_field :email %>
  </div>
  <div class="field">
    <%= f.label :password %><br />
    <%= f.password_field :password %>
  </div>
  <div class="field">
    <%= f.label :password_confirmation %><br />
    <%= f.password_field :password_confirmation %>
  </div>
  <div class="actions"><%= f.submit "Sign Up" %></div>
<% end %>

# views/sessions/new.html.erb
<h1>Log In</h1>

<%= form_tag sessions_path do %>
  <div class="field">
    <%= label_tag :email %><br />
    <%= text_field_tag :email, params[:email] %>
  </div>
  <div class="field">
    <%= label_tag :password %><br />
    <%= password_field_tag :password %>
  </div>
  <div class="actions"><%= submit_tag "Log In" %></div>
<% end %>

# views/layouts/application.html.erb

Code Along

In Class Solution

iexperience.github.io/exercises/18A.html