Implement basic login

app/assets/javascripts/application.js

@@ -9,7 +9,8 @@
 //
 // Read Sprockets README (https://github.com/rails/sprockets#sprockets-directives) for details
 // about supported directives.
-//
+//= require jquery
+//= require bootstrap
 //= require rails-ujs
 //= require turbolinks
 //= require_tree .

app/assets/javascripts/sessions.coffee

+# Place all the behaviors and hooks related to the matching controller here.
+# All this logic will automatically be available in application.js.
+# You can use CoffeeScript in this file: http://coffeescript.org/

app/assets/stylesheets/sessions.scss

+// Place all the styles related to the Sessions controller here.
+// They will automatically be included in application.css.
+// You can use Sass (SCSS) here: http://sass-lang.com/

app/controllers/application_controller.rb

 class ApplicationController < ActionController::Base
   protect_from_forgery with: :exception
-   def hello
+  include SessionsHelper
+   
+  def hello
       render html: "hello,world!"
    end
 end

app/controllers/sessions_controller.rb

+class SessionsController < ApplicationController
+  def new
+  end
+
+  def create
+    user = User.find_by( email: params[ :session ][ :email ].downcase )
+    if user && user.authenticate( params[ :session ][ :password ] )
+      log_in user
+      redirect_to user
+    else
+      flash.now[ :danger ] = "Invalid email/password combination" 
+      render "new"
+    end
+  end
+
+   def destroy
+    log_out
+    redirect_to root_url
+  end
+end
+

app/controllers/users_controller.rb

@@ -11,8 +11,9 @@ class UsersController < ApplicationController
   def create
     @user = User.new(user_params)  
       if @user.save
-        redirect_to @user
+        log_in @user
         flash[:success] = "Welcome to the Sample App!"
+        redirect_to @user
       else
         render "new"
     end

app/helpers/sessions_helper.rb

+module SessionsHelper
+  # Logs in the given user. 
+  def log_in(user)
+    session[:user_id] = user.id 
+  end
+  # Returns the current logged-in user (if any)
+  def current_user
+    if session[ :user_id]
+      @current_user ||= User.find_by( id: session[ :user_id])
+    end
+  end
+
+  # Return true if the user is logged in, false otherwise . 
+  def logged_in?
+    !current_user.nil?
+  end
+
+  # Logs out the current user
+  def log_out
+    session.delete( :user_id )
+    @current_user = nil
+  end
+end

app/models/user.rb

 class User < ApplicationRecord
+  def User.digest(string)
+    cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
+    BCrypt::Engine.cost
+    BCrypt::Password.create(string, cost: cost)
+  end
+
+# Constant
   VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
 
+# Validation macros
   validates :email, presence: true, length: { maximum: 255 }, format: { with: VALID_EMAIL_REGEX }
   validates :name, presence: true, length: { maximum: 50 }, uniqueness: { case_sensitive: false }
   validates :password, presence: true, length: { minimum: 6 }
 
-  before_save { email.downcase! }
+  before_save { email.downcase! } #Call Backs
   
   has_secure_password
 end

app/views/layouts/_header.html.erb

@@ -5,7 +5,24 @@
       <ul class="nav navbar-nav navbar-right">
         <li><%= link_to "Home",    root_path %></li>
         <li><%= link_to "Help",    help_path %></li>
-        <li><%= link_to "Log in", '#' %></li>
+        <% if logged_in? %>
+          <li><%= link_to "Users", '#' %></li>
+        <li class="dropdown">
+          <a href="#" class="dropdown-toggle" data-toggle="dropdown">
+            Account <b class="caret"></b>
+          </a>
+          <ul class="dropdown-menu">
+            <li><%= link_to "Profile", current_user %></li>
+            <li><%= link_to "Settings", '#' %></li>
+            <li class="divider"></li>
+            <li>
+              <%= link_to "Log out", logout_path, method: :delete %>
+            </li>
+          </ul>
+        </li>
+      <% else %>
+        <li><%= link_to "Log in", login_path %></li>
+      <% end %>
       </ul>
     </nav>
   </div>

app/views/sessions/new.html.erb

+<% provide(:title, "Log in") %>
+<h1>Log in</h1>
+
+<div class="row">
+  <div class="col-md-6 col-md-offset-3">
+    <%= form_for(:session, url: login_path) do |f| %>
+      <%= f.label :email %>
+      <%= f.email_field :email, class: "form-control" %>
+      <%= f.label :password %>
+      <%= f.password_field :password, class: "form-control" %>
+      <%= f.submit "Log in", class: "btn btn-primary" %>
+    <% end %>
+    <p>New user? <%= link_to "Sign up now!", signup_path %></p>
+  </div>
+</div>

app/views/users/new.html.erb

@@ -3,7 +3,7 @@
 
 <div class="row">
   <div class="col-md-6 col-md-offset-3">
-    <%= form_for(@user, url: signup_path) do |f| %>
+    <%= form_for(@user) do |f| %>
       <%= render "shared/error_messages" %>
       <%= f.label :name %>
       <%= f.text_field :name, class: "form-control" %>

config/routes.rb

 Rails.application.routes.draw do
   root "static_pages#home"
-  get "users/new"
   get  "/help",    to: "static_pages#help"
   get  "/about",   to: "static_pages#about"
   get  "/contact", to: "static_pages#contact"
   get  "/signup",  to: "users#new"
-  post "/signup",  to: "users#create"
+  get    "/login",   to: "sessions#new"
+  post   "/login",   to: "sessions#create"
+  delete "/logout",  to: "sessions#destroy"
   resources :users
 end

test/controllers/sessions_controller_test.rb

+require "test_helper"
+
+class SessionsControllerTest < ActionDispatch::IntegrationTest
+
+  test "should get new" do
+    get login_path
+    assert_response :success
+  end
+end

test/controllers/users_controller_test.rb

@@ -2,8 +2,7 @@ require "test_helper"
 
 class UsersControllerTest < ActionDispatch::IntegrationTest
   test "should get new" do
-    get users_new_url
+    get signup_path
     assert_response :success
   end
-
 end

test/fixtures/users.yml

-#  empty
-
+michael:
+  name: Michael Example
+  email: michael@example.com
+  password_digest: <%= User.digest("password") %>

test/integration/users_login_test.rb

+require "test_helper"
+
+class UsersLoginTest < ActionDispatch::IntegrationTest
+  def setup
+    @user = users( :michael )
+  end
+
+  test "login with invalid information"  do  
+    get login_path
+    assert_template "sessions/new"
+    post login_path, params:  { session:  { email:  "", password: ""} }
+    assert_template "sessions/new"
+    assert_not flash.empty?
+    get root_path
+    assert flash.empty?
+  end
+
+  test "login with valid information" do
+    get login_path
+    post login_path, params: { session: { email:    @user.email,password: "password" } }
+    assert_redirected_to @user
+    follow_redirect!
+    assert_template "users/show"
+    assert_select "a[href=?]", login_path, count: 0
+    assert_select "a[href=?]", logout_path
+    assert_select "a[href=?]", user_path(@user)
+    end
+
+  test "login with valid information followed by logout" do
+    get login_path
+    post login_path, params: { session: { email:    @user.email,
+    password: "password" } }
+    assert is_logged_in?
+    assert_redirected_to @user
+    follow_redirect!
+    assert_template "users/show"
+    assert_select "a[href=?]", login_path, count: 0
+    assert_select "a[href=?]", logout_path
+    assert_select "a[href=?]", user_path(@user)
+    delete logout_path
+    assert_not is_logged_in?
+    assert_redirected_to root_url
+    follow_redirect!
+    assert_select "a[href=?]", login_path
+    assert_select "a[href=?]", logout_path,      count: 0
+    assert_select "a[href=?]", user_path(@user), count: 0
+  end
+end

test/integration/user_signup_test.rb → test/integration/users_signup_test.rb

@@ -19,6 +19,6 @@ class UsersSignupTest < ActionDispatch::IntegrationTest
     end
     follow_redirect!
     assert_template "users/show" 
-    assert_not flash.empty?
+    assert is_logged_in?
   end
 end

test/test_helper.rb

@@ -6,5 +6,9 @@ class ActiveSupport::TestCase
   # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
   fixtures :all
   include ApplicationHelper
-  # Add more helper methods to be used by all tests here...
+
+  #Returns true if a test user is logged in. 
+  def is_logged_in?
+    !session[:user_id].nil?
+  end
 end