Skip to Content
Agile Web Development with Rails 6
book

Agile Web Development with Rails 6

by Sam Ruby, David B. Copeland, Dave Thomas
February 2020
Intermediate to advanced
496 pages
12h 36m
English
Pragmatic Bookshelf
Content preview from Agile Web Development with Rails 6

Iteration F4: Hiding an Empty Cart with a Custom Helper

The customer has one last request. Right now, even carts with nothing in them are displayed in the sidebar. Can we arrange for the cart to appear only when it has some content? But of course!

In fact, we have a number of options. The simplest is probably to include the HTML for the cart only if the cart has something in it. We could do this totally within the _cart partial:

»<​%​ unless cart​.​line_items​.​empty​?​ ​%​>
 <h2>Your Cart</h2>
 <table>
  <​%=​ render​(​cart​.​line_items​)​ ​%​>
 
  <tr class=​"total_line"​>
  <td colspan=​"2"​>Total</td>
  <td class=​"total_cell"​><​%=​ number_to_currency​(​cart​.​total_price​)​ ​%​></td>
  </tr>
 </table>
 
 <​%=​ button_to ​'​Empty cart​ ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

Agile Web Development with Rails 5.1

Agile Web Development with Rails 5.1

Sam Ruby, David B. Copeland, Dave Thomas

Publisher Resources

ISBN: 9781680507522Errata Page