briancolfer

briancolfer

Agile Web Development with Rails 7: Iteration E2 the add_product method

The add_product method assumes that the default value for the quantity attribute is 0 when it is nil.

I think the code example for add_product:

	​def​ ​add_product​(product)
​ 	  current_item = line_items.​find_by​(​product_id: ​product.​id​)
​ 	  ​if​ current_item
​ 	    current_item.​quantity​ += 1
​ 	  ​else​
​ 	    current_item = line_items.​build​(​product_id: ​product.​id​)
​ 	  ​end​
​ 	  current_item
​ 	​end​

Should be:

  def add_product(product)
​    ​# replace multiple items for a single product in a cart with a​
​    # single item​
    current_item = line_items.find_by(product_id: product.id)
    if current_item
      if current_item.quantity.nil?
        current_item.quantity = 1
      else
        current_item.quantity += 1
      end
    else
      current_item = line_items.build(product_id: product.id, quantity: 1)
    end
    current_item
  end

Marked As Solved

briancolfer

briancolfer

I forgot the default value in the migration.

Where Next?

Popular Pragmatic Bookshelf topics Top

belgoros
Following the steps described in Chapter 6 of the book, I’m stuck with running the migration as described on page 84: bundle exec sequel...
New
ianwillie
Hello Brian, I have some problems with running the code in your book. I like the style of the book very much and I have learnt a lot as...
New
simonpeter
When I try the command to create a pair of migration files I get an error. user=> (create-migration "guestbook") Execution error (Ill...
New
mikecargal
Title: Hands-on Rust: question about get_component (page 295) (feel free to respond. “You dug you’re own hole… good luck”) I have somet...
New
raul
Hi Travis! Thank you for the cool book! :slight_smile: I made a list of issues and thought I could post them chapter by chapter. I’m rev...
New
AndyDavis3416
@noelrappin Running the webpack dev server, I receive the following warning: ERROR in tsconfig.json TS18003: No inputs were found in c...
New
hgkjshegfskef
The test is as follows: Scenario: Intersecting a scaled sphere with a ray Given r ← ray(point(0, 0, -5), vector(0, 0, 1)) And s ← sphere...
New
brunogirin
When running tox for the first time, I got the following error: ERROR: InterpreterNotFound: python3.10 I realised that I was running ...
New
kolossal
Hi, I need some help, I’m new to rust and was learning through your book. but I got stuck at the last stage of distribution. Whenever I t...
New
dtonhofer
@parrt In the context of Chapter 4.3, the grammar Java.g4, meant to parse Java 6 compilation units, no longer passes ANTLR (currently 4....
New

Other popular topics Top

Devtalk
Hello Devtalk World! Please let us know a little about who you are and where you’re from :nerd_face:
New
AstonJ
What chair do you have while working… and why? Is there a ‘best’ type of chair or working position for developers?
New
Exadra37
I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New
PragmaticBookshelf
Build highly interactive applications without ever leaving Elixir, the way the experts do. Let LiveView take care of performance, scalabi...
New
PragmaticBookshelf
Create efficient, elegant software tests in pytest, Python's most powerful testing framework. Brian Okken @brianokken Edited by Kat...
New
PragmaticBookshelf
Use WebRTC to build web applications that stream media and data in real time directly from one user to another, all in the browser. ...
New
PragmaticBookshelf
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
New
New
husaindevelop
Inside our android webview app, we are trying to paste the copied content from another app eg (notes) using navigator.clipboard.readtext ...
New
PragmaticBookshelf
Explore the power of Ash Framework by modeling and building the domain for a real-world web application. Rebecca Le @sevenseacat and ...
New

Latest in Agile Web Development with Rails 7

Agile Web Development with Rails 7 Portal

Sub Categories: