product_card.html.eex

<div class="product thumbnail">
  <div class="caption">
    <span class="text-muted pull-right"><%= @product.pack_size %></span>
    <h2>
      <div class="product-name"><%= @product.name %></div>
      <span class="pull-right">₹ 
        <small class="product-price"><%= @product.price %></small>
      </span>
    </h2>
    <hr/>
    <!-- add to cart code begins -->
    <%= form_for @conn, "/cart", [as: :cart], fn f -> %>
      <%= hidden_input f, :product_id, value: @product.id %>
      <%= number_input f, :quantity, value: 1  %>
      <%= submit "Add to cart" %>
    <% end %>
    <!-- add to cart code ends -->
  </div>
  <img src="<%= @product.image %>" />
</div>