How to get value from other class in Rails - ruby-on-rails

Question

I'm not sure if I am phrasing this question correctly. I am using the Stripe API for a Harry Potter themed Rails online store demo app. I followed the Stripe boilerplate code, so I currently have the amount set at a hardcoded value of $1.00. In my shopping cart, there is a method that displays the total cost of all items in the cart. That works fine, but I can't figure out how to pass that value to the Charges controller so that it sets that as the amount of the payment.
I'm fairly new to Rails, so any helpful explanations would be greatly appreciated.
Here is my charges/new.html.erb file:
<%= form_tag charges_path do %>
<article>
<% if flash[:error].present? %>
<div id="error_explanation">
<p><%= flash[:error] %></p>
</div>
<% end %>
<label class="amount">
<span>Amount: $1.00</span>
</label>
</article>
<script src="https://checkout.stripe.com/checkout.js" class="stripe-button"
data-key="<%= Rails.configuration.stripe[:publishable_key] %>"
data-description="A month's subscription"
data-amount="100"
data-locale="auto"></script>
<% end %>
Here is my Charges controller:
class ChargesController < ApplicationController
include CurrentCart
before_action :set_cart, only: [:new, :create]
def new
end
def create #METHOD IS CALLED AFTER PAYMENT IS MADE
# Amount in cents
#amount = 100
customer = Stripe::Customer.create(
:email => params[:stripeEmail],
:source => params[:stripeToken]
)
charge = Stripe::Charge.create(
:customer => customer.id,
:amount => #amount,
:description => 'Witch or Wizard',
:currency => 'usd'
)
Cart.destroy(session[:cart_id])
rescue Stripe::CardError => e
flash[:error] = e.message
redirect_to new_charge_path
end
end
Here is my carts/show.html.erb file:
<p id="notice"><%= notice %></p>
<h2>My Cart</h2>
<table class="table table-responsive table-striped">
<thead>
<tr>
<th>Item</th>
<th>Quantity</th>
<th>Total Price in Galleons</th>
<th>Total Price in Muggle Currency</th>
</tr>
<tbody>
<%= render(#cart.line_items) %>
<tr>
<td>Total</td>
<td><%= number_to_currency(#cart.total_price * 7.35) %></td>
<td></td>
<td></td>
</tr>
</tbody>
</thead>
</table>
<br>
<div class="row">
<div class="col-md-3">
<div class="row">
<div class="col-md-4">
<%= link_to 'Back', products_path, :class => 'btn btn-primary whiteText' %>
</div>
<div class="col-md-4">
<%= link_to "Checkout", new_charge_path, :class => 'btn btn-success whiteText' %>
</div>
<div class="col-md-4">
<%= link_to 'Empty Cart', #cart, method: :delete, data: {confirm: 'Are you sure you want to empty your cart?'}, :class => 'btn btn-danger whiteText' %>
</div>
</div>
</div>
<div class="col-md-9"></div>
</div>
Here is my Carts controller:
class CartsController < ApplicationController
before_action :set_cart, only: [:show, :edit, :update, :destroy]
rescue_from ActiveRecord::RecordNotFound, with: :invalid_cart
# GET /carts
# GET /carts.json
def index
#carts = Cart.all
end
# GET /carts/1
# GET /carts/1.json
def show
end
# GET /carts/new
def new
#cart = Cart.new
end
# GET /carts/1/edit
def edit
end
# POST /carts
# POST /carts.json
def create
#cart = Cart.new(cart_params)
respond_to do |format|
if #cart.save
format.html { redirect_to #cart, notice: 'Cart was successfully created.' }
format.json { render :show, status: :created, location: #cart }
else
format.html { render :new }
format.json { render json: #cart.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /carts/1
# PATCH/PUT /carts/1.json
def update
respond_to do |format|
if #cart.update(cart_params)
format.html { redirect_to #cart, notice: 'Cart was successfully updated.' }
format.json { render :show, status: :ok, location: #cart }
else
format.html { render :edit }
format.json { render json: #cart.errors, status: :unprocessable_entity }
end
end
end
# DELETE /carts/1
# DELETE /carts/1.json
def destroy
#cart.destroy if #cart.id == session[:cart_id]
session[:cart_id] = nil
respond_to do |format|
format.html { redirect_to root_path, notice: 'Cart was emptied.' }
format.json { head :no_content }
end
end
def update_quantity
#line_item.update_attribute(:quantity)
end
private
# Use callbacks to share common setup or constraints between actions.
def set_cart
#cart = Cart.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def cart_params
params.fetch(:cart, {})
end
def invalid_cart
logger.error "Attempt to access invalid cart #{params[:id]}"
redirect_to root_path, notice: 'Invalid cart'
end
end
Here is my Cart model:
class Cart < ApplicationRecord
has_many :line_items, dependent: :destroy
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
def total_price
line_items.to_a.sum {|item| item.total_price}
end
def convert_to_muggle(galleons)
line_items.to_a.sum {|item| item.convert_to_muggle}
end
end
And here is my routes file:
Rails.application.routes.draw do
resources :charges
resources :orders
resources :line_items
resources :carts
devise_for :users
match 'users/:id' => 'users#destroy', :via => :delete, :as => :admin_destroy_user
resources :users, only: [:index, :show, :edit, :update]
root 'products#index'
resources :products
controller :products do
post '/products/destroy' => 'products#destroy', as: :destroy
get '/products/add_to_cart' => 'products#add_to_cart', as: :add_to_cart
get '/products/remove_from_cart' => 'products#remove_from_cart', as: :remove_from_cart
end
controller :line_items do
post '/line_items/increase_quantity' => 'line_items#increase_quantity', as: :increase_quantity
end
# For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
end

Answer 1

In your charges_controller, change the amount:
#amount = #cart.total_price * 735
And your charges/new.html.erb:
<span>Amount: <%= number_to_currency(#cart.total_price * 7.35) %></span>
and
data-amount="<%= #cart.total_price * 735 %>"
Let me know if that helps.