Question

I am trying to create a basic setup in my cart controller that will allow me to incrementally increase the quantity value of products added to the cart if an Item record already exists.

I currently have:

class ItemsController < ApplicationController

def create  
    @product = Product.find(params[:product_id])

    if @item.new_record?
        @item = Item.create!(:cart => current_cart, :product => @product, :quantity => 1, :unit_price => @product.price)
    else
        @item.increment! :quantity
    end
    redirect_to cart_path(current_cart.id)
end

end

However I keep getting the error undefined methodnew_record?’ for nil:NilClass`

Any help people can offer to solve this really would be much appreciated!

Answer 1

you haven’t anywhere declared @item. before this thats why the error is coming

try this code

def create  
   @product = Product.find(params[:product_id])

if !current_cart.items.exists?(:product_id => @product.id)
    @item = Item.create!(:cart => current_cart, :product => @product, :quantity => 1, :unit_price => @product.price)
else
    current_cart.items.find(:first, :conditions =>{:product_id => @product.id}).increment! :quantity
end
redirect_to cart_path(current_cart.id)
end

This should solve your problem