Value update automatically though javascript is off - ruby-on-rails

Question

In my application I am showing all the products like this
store.html.erb
<% #products.each do |product| %>
<div class="entry" >
<%= image_tag(product.image_url) %>
<h3><%= product.title %></h3>
<%= sanitize(product.description) %>
<div class="price_line" >
<span class="price" ><%= number_to_currency(product.price) %></span>
<%= button_to "add to cart", line_items_path(:product_id => product),
:remote => true %>
</div>
</div>
<% end %>
I am sending ajax request with :remote => true and in my line items controller I don't have any .js format
line_items_controller.rb
def create
#cart = current_cart
product = Product.find(params[:product_id])
#line_item = #cart.add_product(product.id)
respond_to do |format|
if #line_item.save
format.html { redirect_to(store_url) }
format.xml { render :xml => #line_item,
:status => :created, :location => #line_item }
else
format.html { render :action => "new" }
format.xml { render :xml => #line_item.errors,
:status => :unprocessable_entity }
end
end
end
What I understand so far is that, since there is no format.js add to cart should not add any product to the cart and nothing should happen. But when I add .js format in the controller
format.js { #current_item = #line_item }
and update the page I see that add to cart worked behind but did not show the result. after updating the page I see 15 or so items in the cart. How is this happening?

Answer 1

Make changes here
<% #products.each do |product| %>
<div class="entry" >
<%= image_tag(product.image_url) %>
<h3><%= product.title %></h3>
<%= sanitize(product.description) %>
<div class="price_line" >
<span class="price" ><%= number_to_currency(product.price) %></span>
<%= button_to "add to cart", line_items_path(:product_id => product.id),
:remote => true %> #changes line
</div>
</div>
<% end %>
and for update you have to make .js file for that and update elements and onject of html page through jquery or javascript.
And use only one format so controller method go to one responsive area.