app.rb

# encoding: utf-8
require 'rubygems'
require 'sinatra'
require 'sinatra/reloader'
require 'sinatra/activerecord'

set :database, 'sqlite3:pizzashop.db'

class Product < ActiveRecord::Base; end

class Order < ActiveRecord::Base
  validates :name, presence: true
  validates :phone, presence: true
  validates :address, presence: true
end

after do
  ActiveRecord::Base.clear_active_connections!
end

get '/' do
  @products = Product.all
  erb :index
end

get '/about' do
  erb :about
end

post '/cart' do
  @orders_input = params[:orders]
  @items = parse_orders_input @orders_input
  if @items.length == 0
    return erb 'Your cart is empty'
  end
  @items.each do |item|
    item[0] = Product.find(item[0])
  end

  erb :cart
end

def parse_orders_input(orders_input)
  s1 = orders_input.split(',')
  arr = []

  s1.each do |x|
    s2 = x.split('=')
    s3 = s2[0].split('_')
    id = s3[1]
    cnt = s2[1]
    arr2 = [id, cnt]
    arr.push arr2
  end
  arr
end

post '/place_order' do
  @o = Order.new params[:order]
  if @o.save
    erb :order_placed
  else
    @error = @o.errors.full_messages.first
    erb 'Error'
  end
end

get '/something' do
  @orders = Order.all
  erb :orders
end