Agile Web Development with Rails, Edition 5

11.5 Iteration F5: Broadcasting Updates 11.3 Iteration F3: Highlighting Changes

11.4 Iteration F4: Hide an Empty Cart

Expected at least 1 element matching ".total_cell", found 0.
<0> was expected to be
>=
<1>.

Traceback:
  /home/rubys/git/awdwr/edition4/checkdepot.rb:277:in `block in <class:DepotTest>'

Add a blind down visual effect on the first item

Look at the app/helpers directory

ls -p app
assets/
channels/
controllers/
helpers/
jobs/
mailers/
models/
views/
ls -p app/helpers
application_helper.rb
carts_helper.rb
line_items_helper.rb
products_helper.rb
store_helper.rb

Call a render_if helper

edit app/views/layouts/application.html.erb
<!DOCTYPE html>
<html>
  <head>
    <title>Pragprog Books Online Store</title>
    <%= csrf_meta_tags %>
 
    <%= stylesheet_link_tag 'application', media: 'all',
                            'data-turbolinks-track': 'reload' %>
    <%= javascript_include_tag 'application',
                               'data-turbolinks-track': 'reload' %>
  </head>
 
  <body>
    <header class="main">
      <%= image_tag 'logo.svg', alt: 'The Pragmatic Bookshelf' %>
      <h1><%= @page_title %></h1>
    </header>
    <section class="content">
      <nav class="side_nav">
 
        <div id="cart" class="carts">
 
          <%= render_if @cart && @cart.line_items.any?, @cart %>
        </div>
 
        <ul>
          <li><a href="/">Home</a></li>
          <li><a href="/questions">Questions</a></li>
          <li><a href="/news">News</a></li>
          <li><a href="/contact">Contact</a></li>
        </ul>
      </nav>
      <main class='<%= controller.controller_name %>'>
        <%= yield %>
      </main>
    </section>
  </body>
</html>

Implement helper

edit app/helpers/application_helper.rb
module ApplicationHelper
  def render_if(condition, record)
    if condition
      render record
    end
  end
end

hide notice when adding to cart

edit app/views/line_items/create.js.coffee
cart = document.getElementById("cart")
cart.innerHTML = "<%= j render(@cart) %>"
 
notice = document.getElementById("notice")
if notice
  notice.style.display = "none"

Demonstrate emptying and recreating the cart

get /carts/2
The Pragmatic Bookshelf

Your Cart

2 Rails, Angular, Postgres, and Bootstrap $90.00
2 Seven Mobile Apps in Seven Weeks $52.00
Total: $142.00 
post /carts/2
You are being redirected. 
get http://localhost:3000/
The Pragmatic Bookshelf

Your Pragmatic Catalog

  • Rails, Angular, Postgres, and Bootstrap

    Powerful, Effective, and Efficient Full-Stack Web Development As a Rails developer, you care about user experience and performance, but you also want simple and maintainable code. Achieve all that by embracing the full stack of web development, from styling with Bootstrap, building an interactive user interface with AngularJS, to storing data quickly and reliably in PostgreSQL. Take a holistic view of full-stack development to create usable, high-performing applications, and learn to use these technologies effectively in a Ruby on Rails environment.

    $45.00

  • Ruby Performance Optimization

    Why Ruby Is Slow, and How to Fix It You don’t have to accept slow Ruby or Rails performance. In this comprehensive guide to Ruby optimization, you’ll learn how to write faster Ruby code—but that’s just the beginning. See exactly what makes Ruby and Rails code slow, and how to fix it. Alex Dymo will guide you through perils of memory and CPU optimization, profiling, measuring, performance testing, garbage collection, and tuning. You’ll find that all those “hard” things aren’t so difficult after all, and your code will run orders of magnitude faster.

    $46.00

  • Seven Mobile Apps in Seven Weeks

    Native Apps, Multiple Platforms Answer the question “Can we build this for ALL the devices?” with a resounding YES. This book will help you get there with a real-world introduction to seven platforms, whether you’re new to mobile or an experienced developer needing to expand your options. Plus, you’ll find out which cross-platform solution makes the most sense for your needs.

    $26.00 
get /
The Pragmatic Bookshelf

Your Pragmatic Catalog

  • Rails, Angular, Postgres, and Bootstrap

    Powerful, Effective, and Efficient Full-Stack Web Development As a Rails developer, you care about user experience and performance, but you also want simple and maintainable code. Achieve all that by embracing the full stack of web development, from styling with Bootstrap, building an interactive user interface with AngularJS, to storing data quickly and reliably in PostgreSQL. Take a holistic view of full-stack development to create usable, high-performing applications, and learn to use these technologies effectively in a Ruby on Rails environment.

    $45.00

  • Ruby Performance Optimization

    Why Ruby Is Slow, and How to Fix It You don’t have to accept slow Ruby or Rails performance. In this comprehensive guide to Ruby optimization, you’ll learn how to write faster Ruby code—but that’s just the beginning. See exactly what makes Ruby and Rails code slow, and how to fix it. Alex Dymo will guide you through perils of memory and CPU optimization, profiling, measuring, performance testing, garbage collection, and tuning. You’ll find that all those “hard” things aren’t so difficult after all, and your code will run orders of magnitude faster.

    $46.00

  • Seven Mobile Apps in Seven Weeks

    Native Apps, Multiple Platforms Answer the question “Can we build this for ALL the devices?” with a resounding YES. This book will help you get there with a real-world introduction to seven platforms, whether you’re new to mobile or an experienced developer needing to expand your options. Plus, you’ll find out which cross-platform solution makes the most sense for your needs.

    $26.00 
post /line_items?product_id=2
You are being redirected. 
get http://localhost:3000/
The Pragmatic Bookshelf

Your Pragmatic Catalog

  • Rails, Angular, Postgres, and Bootstrap

    Powerful, Effective, and Efficient Full-Stack Web Development As a Rails developer, you care about user experience and performance, but you also want simple and maintainable code. Achieve all that by embracing the full stack of web development, from styling with Bootstrap, building an interactive user interface with AngularJS, to storing data quickly and reliably in PostgreSQL. Take a holistic view of full-stack development to create usable, high-performing applications, and learn to use these technologies effectively in a Ruby on Rails environment.

    $45.00

  • Ruby Performance Optimization

    Why Ruby Is Slow, and How to Fix It You don’t have to accept slow Ruby or Rails performance. In this comprehensive guide to Ruby optimization, you’ll learn how to write faster Ruby code—but that’s just the beginning. See exactly what makes Ruby and Rails code slow, and how to fix it. Alex Dymo will guide you through perils of memory and CPU optimization, profiling, measuring, performance testing, garbage collection, and tuning. You’ll find that all those “hard” things aren’t so difficult after all, and your code will run orders of magnitude faster.

    $46.00

  • Seven Mobile Apps in Seven Weeks

    Native Apps, Multiple Platforms Answer the question “Can we build this for ALL the devices?” with a resounding YES. This book will help you get there with a real-world introduction to seven platforms, whether you’re new to mobile or an experienced developer needing to expand your options. Plus, you’ll find out which cross-platform solution makes the most sense for your needs.

    $26.00 
rails test
Run options: --seed 64992
 
# Running:
 
...............................
 
Finished in 0.645492s, 48.0254 runs/s, 103.7968 assertions/s.
31 runs, 67 assertions, 0 failures, 0 errors, 0 skips

11.5 Iteration F5: Broadcasting Updates 11.3 Iteration F3: Highlighting Changes