Sometimes one layout (application.html.erb) just doesn’t cut it, but you don’t want a separate layout for each controller in your app. You can use the following technique to nest your Rails app’s layouts:

In this example, there are two controllers for a simple todo list manager; lists and tasks

#  application.html.erb
      TODO >> <%= yield(:title) || "Get things done!" %>
    <%= stylesheet_link_tag 'todo' %>
    <div id="container">
      <p style="color: green"><%= flash[:notice] %></p>

      <%= yield :main %>

The key here is the yield :main which means we can use content_for to put our nested layouts’ output inside the yield. Here is the lists layout:

# lists.html.erb
<% content_for :main do %>
  <div id="lists_container">
    <%= yield %>
<% end %>
<%= render :file  => "layouts/application.html.erb" %>

Now your view gets rendered inside this layout’s yield and its all good in the hood. Cheers!