How to render same form on the same page? - ruby-on-rails

Question

I'm curious to know how this is done. Lets say I have a simple Product model and on one page wanted to click a link and add a product form by AJAX. I than pop up other product forms, finish the first one and submit it and do the same to the others.
Here is the code I will use.
On the index page you can add a product form by the link, create it and see it in a list.
products/index.html.erb
<h1>Products</h1>
<%= link_to "Product", new_product_path, :remote => true %>
<div id="product_form">
<%= render 'form' %>
</div>
<ul id="products">
<%= render :partial => #products.reverse %>
</ul>
products/_form.html.erb
<%= form_for(#product, :remote => true) do |f| %>
<%= f.text_field :name %>
<%= f.text_field :price %>
<%= f.submit %>
<% end %>
products/_product.html.erb
<%= content_tag_for(:li, product) do %>
<p><%= product.name</p>
<p><%= product.price %></p>
<% end %>
ProductsController
def index
#products = Product.all
#product = Product.new
end
def create
#product = Product.new(params[:product])
respond_to do |format|
if #product.save
format.html { redirect_to products_url }
format.js
else
format.html { render action: "index" }
format.js
end
end
end
When it gets created it should show the product in the _product partial.
products/create.js.erb
$('#products').prepend('<%= escape_javascript(render(#product)) %>');
The link when clicked will make the product form appear in the <div id="product_form">
products/new.js.erb
$("#product-form").html("<%= escape_javascript(render(:partial => 'products/form', locals: { product: #product })) %>");
Now this generates one product form but I want to know the code logic behind rendering other product forms on the same page. How would this be done?

Answer 1

Usually I do this with a second object representing the collection of products. This can be an activerecord if it fits your business logic (something like a ProductCategory, or a ShoppingCart) or a simple ActiveModel "Products" with a save method that would save each of its related products.
Active Presenter can give you more details of this mechanism but I wouldn't use that gem since it's activity is quite low.