Cache only the main content in rails

Question

Using Rails 3.1.1 and Heroku.

I believe this should be a fairly easy fix but I cannot find (and easily verify) how to do this. I have a very slow controller (6 sec)

Answer 1

Use fragment caching, and don't load things in the controller.

If you have a very complex query, let it live in the controller as a scope, and only evaluate it in the view.

If you have a complex process to do so the query must be executed, use a helper method.

If you manage to just load lazy queries in the controller, if the cache is hit none of them will be executed.

Answer 2

You can achieve this with fragment caching like below:

def show

  if !fragment_exist?("main_content")
    @products = Product.all
    @users_count = User.count
  end

  @random_products = Product.order("RANDOM()").limit(10)

end

show.html.erb

<!--MAIN CONTENT-->
<% cache("main_content") do %>
    <%= @users_count %>
    <% @products.each do |product| %>
        <%= product.name %>
    <% end %>
<% end %>

<!--SIDE CONTENT-->
<% @random_products.each do %>
    <%= product.name %>  
<% end %>