user login

app/controllers/application_controller.rb

@@ -1,3 +1,12 @@
 class ApplicationController < ActionController::Base
+    include SessionsHelper  #追記
     include Pagy::Backend  #追記
+
+    private
+
+    def require_user_logged_in
+      unless logged_in?
+        redirect_to login_url
+      end
+    end
 end

app/controllers/sessions_controller.rb

@@ -0,0 +1,36 @@
+class SessionsController < ApplicationController
+  def new
+  end
+
+  def create
+    email = params[:session][:email].downcase
+    password = params[:session][:password]
+    if login(email, password)
+      flash[:success] = 'ログインに成功しました。'
+      redirect_to @user
+    else
+      flash.now[:danger] = 'ログインに失敗しました。'
+      render :new
+    end
+  end
+
+  def destroy
+    session[:user_id] = nil
+    flash[:success] = 'ログアウトしました。'
+    redirect_to root_url
+  end
+
+  private
+
+  def login(email, password)
+    @user = User.find_by(email: email)
+    if @user && @user.authenticate(password)
+      # ログイン成功
+      session[:user_id] = @user.id
+      return true
+    else
+      # ログイン失敗
+      return false
+    end
+  end
+end

app/controllers/users_controller.rb

@@ -1,4 +1,6 @@
 class UsersController < ApplicationController
+  before_action :require_user_logged_in, only: [:index, :show]
+
   def index
     @pagy, @users = pagy(User.order(id: :desc), items: 25)
   end

app/helpers/sessions_helper.rb

@@ -0,0 +1,9 @@
+module SessionsHelper
+    def current_user
+    @current_user ||= User.find_by(id: session[:user_id])
+  end
+
+  def logged_in?
+    !!current_user
+  end
+end

app/views/layouts/_navbar.html.erb

@@ -5,12 +5,27 @@
       <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent">
         <span class="navbar-toggler-icon"></span>
       </button>
-
+      
       <div class="collapse navbar-collapse justify-content-end" id="navbarSupportedContent">
+        <% if logged_in? %>
+        <div class="btn-group">
+          <ul class="navbar-nav">
+            <li class="ms-3"><%= link_to 'Users', users_path, class: 'nav-link' %></li>
+          </ul>
+
+          <button type="button" class="btn btn-dark dropdown-toggle" data-bs-toggle="dropdown" aria-expanded="false"><%= current_user.name %></button>
+          <ul class="dropdown-menu dropdown-menu-end">
+            <li class="dropdown-item"><%= link_to 'My profile', user_path(current_user), class: 'nav-link' %></li>
+            <li class="dropdown-divider"></li>
+            <li class="dropdown-item"><%= link_to 'Logout', logout_path, method: :delete, class: 'nav-link' %></li>
+          </ul>
+        </div>
+        <% else %>
         <ul class="navbar-nav">
           <li class="nav-item"><%= link_to 'Signup', signup_path, class: 'nav-link' %></li>
-          <li class="nav-item"><a href="#" class="nav-link">Login</a></li>
+          <li class="nav-item"><%= link_to 'Login', login_path, class: 'nav-link' %></li>
         </ul>
+        <% end %>
       </div>
     </div>
   </nav>

app/views/sessions/create.html.erb

@@ -0,0 +1,2 @@
+<h1>Sessions#create</h1>
+<p>Find me in app/views/sessions/create.html.erb</p>

app/views/sessions/destroy.html.erb

@@ -0,0 +1,2 @@
+<h1>Sessions#destroy</h1>
+<p>Find me in app/views/sessions/destroy.html.erb</p>

app/views/sessions/new.html.erb

@@ -0,0 +1,25 @@
+<div class="text-center">
+  <h1>Log in</h1>
+</div>
+
+<div class="row">
+  <div class="col-sm-6 offset-sm-3">
+
+    <%= form_with(url: login_path, scope: :session) do |f| %>
+
+      <div class="mb-3">
+        <%= f.label :email, 'Email' %>
+        <%= f.email_field :email, class: 'form-control' %>
+      </div>
+
+      <div class="mb-3">
+        <%= f.label :password, 'Password' %>
+        <%= f.password_field :password, class: 'form-control' %>
+      </div>
+
+      <%= f.submit 'Log in', class: 'btn btn-primary w-100' %>
+    <% end %>
+
+    <p>New user? <%= link_to 'Sign up now!', signup_path %></p>
+  </div>
+</div>

config/routes.rb

@@ -1,6 +1,10 @@
 Rails.application.routes.draw do
   root to: 'tasks#index'
 
+  get 'login', to: 'sessions#new'
+  post 'login', to: 'sessions#create'
+  delete 'logout', to: 'sessions#destroy'
+
   get 'signup', to: 'users#new'
   resources :users, only: [:index, :show, :create]
   resources :tasks