How to add several items in shopping cart in rails?

Question

I have some problem in my simple shop in rails. I want to add group of chosen products in cart, but I don't know how.

I use radio buttons on my 3 groups of products and I want user choose all 3 items and then press the button "add to cart".

In cart it's must by array like this: username-mix(1-id, 2-id, 3-id). But i have one more problem. I can't get id's of my products and don't know why.

Products are all from seed.db with fields: :category_id, :menu_id, :title, :price, :discribe and:path_to_image .

Here is my code:

 class ProductController < ApplicationController
   before_action :admin_user, only: :edit

   def show
     @products = Product.where("category_id = 1").limit(3)
     @products2 = Product.where("category_id = 2").limit(3)
     @products3 = Product.where("category_id = 3").limit(3)
   end

   private

   def product_params
     params.permit(
       :category_id,
       :menu_id,
       :title,
       :discribe,
       :price,
       :path_to_image
     )
   end
 end

My Product model:

class Product < ApplicationRecord
  validates :title, presence: true
  validates :price, presence: true
  belongs_to :category
end

product/show/html.erb

<div class="col-md-4 about-left">
  <table class="tfood">
    <td><p><b>Main</b></p></td>
    <% @products.each do |i| %>
      <tr>
        <td>
          <%= i.title %><%= image_tag i.path_to_image %>
        </td>
        <td>
          <%= i.discribe %>
          <p><b>Price: <%= i.price %></b></p>
          <input name="main" type="radio" value="">
        </td>
      </tr>
    <% end %>
  </table>
</div>
<div class="col-md-4 about-left">
  <table class="tfood">
    <td>
      <p><b>Topping</b></p>
    </td>
    <% @products2.each do |i| %>
      <tr>
        <td>
          <%= i.title %>
          <%= image_tag i.path_to_image %>
        </td>
        <td>
          <%= i.discribe %>
          <p><b>Price: <%= i.price %></b></p>
          <input name="topping" type="radio" value="">
        </td>
      </tr>
    <% end %>
  </table>
</div>
<div class="col-md-4 about-left">
  <table class="tfood">
    <td>
      <p><b>Drink</b></p>
    </td>
    <% @products3.each do |i| %>
      <tr>
        <td>
          <%= i.title %>
          <%= image_tag i.path_to_image %>
        </td>
        <td>
          <%= i.discribe %>
          <p><b>Price: <%= i.price %></b></p>
          <input name="drink" type="radio" value="">
        </td>
      </tr>
    <% end %>
  </table>
</div>
<script>
  function add_to_cart(id){
    var x = window.localStorage.getItem(id);
    x = x * 1 + 1;
    window.localStorage.setItem(id, x);
  }
</script>

Answer 1

It's look like you didn't set value inside your radio-buttons. Maybe it will be better write something like

<input name="drink" type="radio" value=<%= i.id %>>

Note. I didn't check my code in the IDE, it's just thoughts. Actually I worked with ERB about year ago and I'm not sure about syntax.