4-auth/app/views/layouts/application.html.erb

<%#
  Copyright 2015, Google, Inc.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
%>

<!DOCTYPE html>
<html>
  <head>
    <title>Bookshelf - Ruby on Google Cloud Platform</title>
    <meta charset="utf-8">
    <meta name="viewset" content="width=device-width, initial-scale=1">
    <%= stylesheet_link_tag "//maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" %>
    <%= javascript_include_tag "application" %>
    <%= csrf_meta_tags %>
  </head>
  <body>
    <div class="navbar navbar-default">
      <div class="container">
        <div class="navbar-header">
          <div class="navbar-brand">Bookshelf</div>
        </div>
        <ul class="nav navbar-nav">
          <li><%= link_to "Books", root_path %></li>
          <%# [START mine] %>
          <% if logged_in? %>
            <li><%= link_to "Mine", user_books_path %></li>
          <% end %>
          <%# [END mine] %>
        </ul>
        <p class="navbar-text navbar-right">
          <%# [START user_profile] %>
          <% if logged_in? %>
            <% if current_user.image_url %>
              <%= image_tag current_user.image_url, class: "img-circle", width: 24 %>
            <% end %>
            <span>
              <%= current_user.name %> &nbsp;
              <%# [START logout] %>
              <%= link_to "(logout)", logout_path %>
              <%# [END logout] %>
            </span>
          <%# [END user_profile] %>
          <% else %>
            <%# [START login] %>
            <%= link_to "Login", login_path %>
            <%# [END login] %>
          <% end %>
        </p>
      </div>
    </div>
    <div class="container">
      <% if flash.any? %>
        <% flash.each do |type, message| %>
          <div class="alert alert-<%= type %>"><%= message %></div>
        <% end %>
      <% end %>
      <%= yield %>
    </div>
  </body>
</html>