How to add a class inside a module - ruby

Question

So I've made a very simple command line app in Ruby - which loads product data from a JSON file, displays products to user, user can add them to their cart, the cart applies discount and displays the total.
I have the Products and Cart in modules and have managed to refactor the products so they are a class too (Which makes it easier for testing etc).
However I cannot work out how to successfully change the Cart into a class Cart inside the Cart module..
I don't want to create a new cart each time a product is added.. just want to add to the array
Any feedback and guidance is welcome :)
Files (5)
shop
require_relative './app/controller'
shop = Controller.new
shop.run
controller
require_relative './cart'
require_relative './product'
require_relative './menu'
class Controller
def initialize
#menu = Menu.new
end
def run
loop do
#menu.display_menu
end
end
end
menu
require 'tty-prompt'
require_relative './product.rb'
require_relative './cart.rb'
class Menu
puts "Hi, welcome to Bob's Bits the #1 CLI Shop"
def display_menu
puts "--------------------------------------------------------------"
prompt = TTY::Prompt.new
menu_selection = prompt.select("Select a menu item", ["View All Products", "View Shopping Cart", "Exit"])
case menu_selection
when "View All Products"
Products::view_all_products
when "View Shopping Cart"
Cart::view_shopping_cart
when "Exit"
puts "Goodbye"
exit
end
end
end
product
require 'json'
module Products
class Product
attr_accessor :uuid, :name, :price
def initialize(uuid, name, price)
#uuid = uuid
#name = name
#price = price
end
end
def self.view_all_products
# # Open & load products file (parse and read)
file = File.open "./products.json"
product_data = JSON.load file
product_list = product_data.each do | product |
Product.new(product["uuid"], product["name"], product["price"])
end
# Print out each items name for the menu selection
options = []
product_list.each do | item |
details = item["name"] + " $" + ('%.2f' % item["price"]).to_s
options.push(details)
end
# List product names so that user can select
prompt = TTY::Prompt.new
puts `clear`
item_to_add_to_cart = prompt.select("Select which items to add to cart", options)
# Match the name selected with product
product_for_cart = product_list.select do |product |
item_to_add_to_cart.include?(product["name"])
end
Cart::add_to_cart(product_for_cart)
end
end
cart
require 'tty-prompt'
module Cart
#shopping_cart = []
# Add the product selected to the shopping cart array
def self.add_to_cart(product_for_cart)
#shopping_cart.push(product_for_cart).flatten!
puts `clear`
end
def self.view_shopping_cart
# apply promo discounts based on cart subtotal
def self.discount_calc
# calculator subtotal of items in cart
subtotal = #shopping_cart.map {|item| item["price"]}.sum
#cart_data = {}
# track the discount for display & calc later on
if subtotal >= 100.0
#cart_data[:discount] = 20
elsif subtotal >= 50
#cart_data[:discount] = 15
elsif subtotal >= 20.0
#cart_data[:discount] = 10
else
#cart_data[:discount] = 0
end
#cart_data[:total] = (subtotal - (subtotal * #cart_data[:discount] / 100.00))
#cart_data[:savings] = subtotal - #cart_data[:total]
return #cart_data
end
# run the discount calculator
discount_calc
# Output cart to the user
puts ""
puts "Products in Shopping Cart:"
#shopping_cart.each_with_index do | item, i |
puts " #{i + 1}. #{item["name"]} - $#{'%.2f' % item["price"]}\n\n"
end
puts "Discount applied: #{#cart_data[:discount]}% (Total Savings $#{'%.2f' % #cart_data[:savings]}!)\n\n"
puts "Total After Discount: $#{'%.2f' % #cart_data[:total]}\n\n"
end
end

Answer 1

You can pass a cart as a parameter to constructors and methods
class Cart
def initialize
#shopping_cart = []
end
# ...
end
module Products
# ...
def self.view_all_products(cart)
# ...
cart.add_to_cart(product_for_cart)
end
end
class Menu
puts "Hi, welcome to Bob's Bits the #1 CLI Shop"
def initialize(cart)
#cart = cart
end
def display_menu
puts "--------------------------------------------------------------"
prompt = TTY::Prompt.new
menu_selection = prompt.select("Select a menu item", ["View All Products", "View Shopping Cart", "Exit"])
case menu_selection
when "View All Products"
Products::view_all_products(#cart)
when "View Shopping Cart"
#cart.view_shopping_cart
when "Exit"
puts "Goodbye"
exit
end
end
end
class Controller
def initialize
#cart = Cart.new
#menu = Menu.new(#cart)
end
def run
loop do
#menu.display_menu
end
end
end
shop = Controller.new
shop.run